Investigation of greenhouse gas emissions from the production of tin cans - An evaluation of the EcoProIT method Master of Science Thesis in Production Engineering JOAKIM LARSSON MARINETTA TÖRNBERG Department of Product and Production Development Division of Production Systems CHALMERS UNIVERSITY OF TECHNOLOGY Göteborg, Sweden, 2013 Investigation of greenhouse gas emissions from the production of tin cans - An evaluation of the EcoProIT method JOAKIM LARSSON MARINETTA TÖRNBERG Department of Product and Production Development CHALMERS UNIVERSITY OF TECHNOLOGY Göteborg, Sweden 2013 Investigation of greenhouse gas eimissions from the production of tin cans - An evaluation of the EcoProIT method JOAKIM LARSSON MARINETTA TÖRNBERG © JOAKIM LARSSON & MARINETTA TÖRNBERG, 2013 Master of Science Thesis Work Department of Product and Production Development Chalmers University of Technology SE-412 96 Göteborg Sweden Telephone: + 46 (0)31-772 1000 Front cover: Superstudio Caption: EcoProIT Method Chalmers Reproservice Göteborg, Sweden, 2013 Preface This master thesis was carried out during spring term 2012 at the institution for Product and Production Development at Chalmers University of Technology. The Master programme was Production Engineering and the Thesis covers 30 credits. We would like to thank Emballator Ulricehamns Bleck and EcoProIT for the opportunity to participate in this project. The supervisor was Jon Andersson and the examiner was Björn Johansson as a member of the EcoProIT project Anders Skoogh was also available for support during the master thesis. We would like to thank them for their support during this project. We would also like to thank everybody at Emballator Ulricehamns Bleck for answering our many questions with a smile. June 2013, Göteborg Joakim Larsson & Marinetta Törnberg Abstract The interest for the environment among industries has increased in recent years. One reason is the demands from legislations and restrictions getting harsher as well as higher demands from customers. Emballator Ulricehamn’s Bleck is a packaging company with an environmental conscious. They wish to know how much environmental impact their products have, expressed by a Global-warming Potential (GWP) value. EcoProIT (2010-2013) is a project working on combining the increasing use of Discrete-event Simulation (DES) models with Activity-based costing (ABC) to investigate this. Instead of measuring monetary values the ABC and the DES will measure time and consumption of energy to calculate a more dynamic GPW value. This master thesis has evaluated the EcoProIT model by investigating the GWP value of 2.5l – 6l (production line 180-1) cans at Emballator. The conclusions show that the GWP value varies from ~2.37 GWPs for a 2.5l can to ~4,35 for a 6l can. The model shows that the variation for one can vary, for example a 2,5 litres varies between ~2,19 and ~2,88 GWPs. The most significant in house contribution to the GWP value is waste materials and processes and it is recommended to further analyse the waste in the production flow. The conclusions drawn after working with the EcoProIT method is that a pre-study should be performed before embarking on a similar product. The pre-study should focus on which parts of the production system that have the highest impact in terms on GWP value. The study will help when identifying important parameters and accuracy requirements that are needed to move forward in the project as well as deciding how and what parts of an existing DES-model built with production objectives in mind. DES-model need to be modified. This master thesis recommends that the EcoProIT method is evaluated on an existing DES model. Table of Content 1. Introduction ...................................................................................................... 1 1.1 Background ......................................................................................................................... 1 1.2 Purpose and objective .......................................................................................................... 2 1.3 Problem formulation ............................................................................................................ 2 1.4 Delimitations ....................................................................................................................... 3 1.6 Factory description .............................................................................................................. 4 1.7 Disposition ........................................................................................................................... 4 2. Theory .............................................................................................................. 5 2.1 Global warming ................................................................................................................... 5 2.1.1 Greenhouse gases ........................................................................................................ 5 2.2 Life Cycle Assessment ........................................................................................................ 6 2.3 Steel industry ....................................................................................................................... 7 2.4 Ecolabeling .......................................................................................................................... 8 2.4.1 Type I - Environmental labeling .................................................................................. 8 2.4.2 Type II - Self declared environmental claims............................................................... 8 2.4.3 Type III – Environmental declaration .......................................................................... 9 2.5 Activity-based Costing ........................................................................................................ 9 2.6 Discrete-event Simulation ................................................................................................... 9 2.6.1 Demands on input data for a traditional DES project ............................................... 10 2.6.2 Input data management method ................................................................................. 11 3. Method ........................................................................................................... 15 3.1 Description of the EcoProIT method ................................................................................. 15 3.2 Method for evaluating the EcoProIT method .................................................................... 18 3.3 Conduction of the EcoProIT method ................................................................................. 21 3.3.1 Concept ...................................................................................................................... 21 3.3.2 Data gathering ........................................................................................................... 22 3.3.3 Modelling ................................................................................................................... 22 3.3.4 Verify the model traditionally .................................................................................... 23 3.3.5 Validate the model traditionally ................................................................................. 23 3.3.6 Verify the calculations for environmental impact ...................................................... 24 3.3.7 Validate the calculations for environmental impact .................................................. 24 4. System description .......................................................................................... 25 4.1 Information flow ................................................................................................................ 25 4.2 Production flow ................................................................................................................. 25 4.2.1 Surface treatment ....................................................................................................... 27 4.2.2 Main production line .................................................................................................. 27 4.2.3 Post production .......................................................................................................... 28 4.2.4 Lid production ............................................................................................................ 28 4.2.5 Bottom production ...................................................................................................... 29 4.2.6 Ear production ........................................................................................................... 29 4.2.7 Buffer and storage areas ............................................................................................ 29 4.3 Energy flow ....................................................................................................................... 30 4.4 Data gathering and data to information transformation ..................................................... 30 4.4.1 Process data ............................................................................................................... 30 4.4.2 Material data .............................................................................................................. 31 4.4.3 Order, contracts, transportation and buffer data ...................................................... 32 4.4.4 Energy consumption ................................................................................................... 33 4.4.5 Distribution factors .................................................................................................... 34 4.5 Model description .............................................................................................................. 34 4.5.1 Enamel process .......................................................................................................... 35 4.5.2 Printing press ............................................................................................................. 35 4.5.3 Can production line ................................................................................................... 36 4.5.4 Bottom and lid ............................................................................................................ 36 4.5.5 Validation ................................................................................................................... 36 4.5.6 Excel interface ............................................................................................................ 37 4.5.7 Delimitations of the model ......................................................................................... 37 5. Result ............................................................................................................. 39 5.1 Generic Result from Field Notes ....................................................................................... 39 5.1.1 Time Comparison ....................................................................................................... 39 5.1.2 Result Accuracy .......................................................................................................... 40 5.1.3 Possibility to update and maintain model .................................................................. 41 5.2 The Emballator production system and EcoProIT method................................................ 41 5.3 GWP result from the model ............................................................................................... 43 5.3.1 In house contributions ................................................................................................ 44 5.3.2 Material GWP contribution ....................................................................................... 45 5.3.3 Waste Contribution .................................................................................................... 46 6. Analysis .......................................................................................................... 49 6.1 Problem identification of the EcoProIT method ................................................................ 49 6.1.1 Suggested improvements ............................................................................................ 49 6.2 Analysis of GWP result ..................................................................................................... 52 6.2.1 Analysis of in house contributions ............................................................................. 53 6.2.2 Analysis of material contribution ............................................................................... 53 7. Discussion ....................................................................................................... 55 7.1 Evaluation method discussion ........................................................................................... 55 7.2 Evaluation result discussion .............................................................................................. 55 7.3 GWP result discussion ....................................................................................................... 56 8. Conclusions and recommendations ................................................................. 59 8.1 Conclusions and recommendations regarding the EcoProIT method ................................ 59 8.2 Conclusions and recommendations from model result ...................................................... 59 9. References ...................................................................................................... 61 Appendix I .............................................................................................................. Appendix II ............................................................................................................. Definitions and abbreviations ABC – Activity-based Costing AGV - Automated Guided Vehicle DES – Discrete-event Simulation EcoProIT method – Method developed by the EcoProIT project (2010-2013) EcoProIT model – The model created using the EcoProIT method GWP - Global-warming Potential ISO – International Standard Organisation LCA - Life Cycle Assessment LCI - Life Cycle Inventory LPG - Liquefied Petroleum Gas MTTF - Mean time to failure MTTR - Mean time to repair SOU - Statens Offentliga Utredningar SMHI - Sveriges Metrologiska och Hydrologiska Institut 1 1. Introduction In recent years there has been an increased focus on environmental research and sustainable production. Government restrictions as well as EU regulations are issued regularly for a variety of industries, most prominent among the car industry controlling the CO2 emissions etc (Cuenot 2009). EcoProIT is an on-going project at Chalmers and the main objective is to enable labelling of products and a tool for evaluating the environmental footprints during the lifecycle of a product. To then be able to connect several steps in the product lifecycle and get a final dynamic environmental impact. Different EcoProIT models should create a cluster or a chain as work together to support each other’s GWP calculations. A part of EcoProIT’s project aims to develop a new tool and methodology (the EcoProIT method) for environmental evaluations using DES. The thought behind the EcoProIT method is that is should be possible to implement on an existing DES model (Andersson et al 2011). 1.1 Background Emballator is a market leading packaging manufacturer with strong environmental and quality focus. They provide metal and plastic packages to food, paint and technical chemistry industries. The packages range from bottles, bottle caps to cans and containers. Emballator Ulricehamn's Bleck, here after referred to as Emballator, produce cans ranging from 0,33l to 25l where the majority of the customers are in the paint industry. As a mean toward becoming an even more sustainable company, Emballator wish to label their products with environmental metrics. This would enhance their environmental profile among their customers as well as create and advantage against their competitors (Gallego-Álvarez et al. 2010). Emballator anticipates similar restrictions and regulations, as those in the car industry, within their own field, as well as their customers' field. They view this master thesis as a proactive measure. Traditionally Discrete-event Simulation (DES) has been used to evaluate the relationship between monetary units, materials, time and other resources (Banks 2004, Banks 1999). With an Activity-based Costing calculation (ABC), activities in an organization are identified and indirect and direct costs are allocated to the product or services in accordance to their respective consumption of these activities (Skärvad & Olsson). Both are traditionally used separately, von Beck and Nowak (2000) showed that an ABC calculation can be implemented in a DES model. Emblemsvåg (2001) showed that ABC calculations suit well when performing an environmental impact analysis (Life Cycle Assessment, LCA). This is supported by a recent study by Andersson et al (2011) that conclude that ABC calculations in a DES model is a suitable combination to perform a LCA for a manufacturing system. This master thesis aims to implement this in a real world scenario by using the EcoProIT method that is under development. 2 1.2 Purpose and objective The purpose of this master thesis is to analyse green house gas emissions, expressed as Global-warming Potential (GWP) to provide Emballator with relevant environmental data that can be used as a basis for an ecolabel on their product or in a product catalogue. This master thesis will also provide researchers from the EcoProIT project with a test implementation of environmental metrics in DES for enabling the development of a new methodology and tool for environmental evaluations using DES here after referred to as the EcoProIT method. The objectives of this master thesis are:  To find the amount of greenhouse gases produced in the current state, measured per product.  To find all sources of greenhouse gases for the product and identify the most significant sources, contributing with at least 80% of the total GWP value.  To use and evaluate the EcoProIT method. 1.3 Problem formulation This master thesis will answer the three main-questions below. To help Emballator improve their GWP value this master thesis will also answer sub question 1a. For Emballator's environmental commitment to reach out to their customers it is important that they (Emballator) know how they can and are allowed to use the GWP values. MQ1 How much greenhouse gases (expressed in GWP) are omitted to produce one product (can + lid)? SQ1 What can Emballator do to reduce their greenhouse gas emissions? There is no current method to follow when working with environmental factors and DES. This is one of the questions EcoProIT is trying to solve. The insecurities regarding the EcoProIT model is investigated by answering the sub-questions. MQ2 Is EcoProIT’s method suitable when investigating GWP impact? SQ2a What are the differences between the input data management for the EcoProIT method and the data for a LCA or a traditional DES? SQ2b What are the difficulties when verifying and validating a model created with the EcoProIT method in terms of environmental aspects? These questions will be investigated with the focus on the following areas:  Time consumption  Result accuracy  Possibility to maintain and update the model. 3 1.4 Delimitations The following points define the general delimitations for this master thesis.  This thesis will consider all activities inside the factory until the products leave Emballator (gate to gate). Environmental metrics from preproduction, scrap in production, usage and recycling and the end of the product life cycle will be taken into consideration but will not be investigated further.  Measurements for energy consumption on the machines/processes were done during the spring 2012 and are assumed to be valid for the whole year.  DES model will only analyze products produced at the 180-1 production line at Emballator.  The DES-model will be based on process and production data but will not be used to make production analysis or consider economic factors.  The EcoProIT method is still under development and the description available so far will be followed. Changes to the method during the time of this thesis will be taken into consideration if they are possible or applicable.  The EcoProIT method will be evaluated by execution, focusing on the questions in the problem formulation (SQ2a and SQ2b).  Comparisons between the EcoProIT method and similar or related methods will only regard SQ2a and SQ2b. Delimitations concerning the model will be further described in chapter 4.5.7 Delimitations of the model. 4 1.6 Factory description Emballator's factory in Ulricehamn produces a wide range of metal cans in different sizes. The cans are slightly conical to improved decrease storage volume and stack ability. There are many ways to design the cans to fit customer’s needs. For example; handles or no handles, a range of different lids and the printing on the cans can be specific for each batch. Emballator manufacture several different can sizes. The size focused on in this master thesis has the top diameter 180mm and is a conical can. The line where the cans are produced is one of two manufacturing this size, 180-1 and 180-2. Depending on the height of the can different volumes are achieved. The 180-1 production line manufacture 2.5l, 3l, 4l, 5l and 6l cans. The cans are produced from metal sheets stored in a raw material buffer. The sheets are processed through an enamel paint machine and a printing press before stored in the printed sheet buffer. The sheets are stored in this buffer until Emballator receives an order for those cans. The sheets are moved to the 180-1 production line where they are cut and formed into cans. A bottom and an optional gripping wire are attached. The system will be described in further detail in chapter 4. System description. 1.7 Disposition This master thesis will continue with a theoretical framework describing important aspects for the purpose of this project. Thereafter the EcoProIT method will be described. This will be followed by a system description, which includes the information flow, the production flow, the energy flow, and a model description. After that the results from the EcoProIT model will be presented followed by an analysis of the result and evaluation of the EcoProIT method. The discussion will handle the above-mentioned chapters and which results in the conclusions and recommendations. Lid Bottom Gripping wire Ear Mantel area Plastic handle Figure 1 The different components of a can that will be discussed in the report 5 2. Theory To be able to answer the questions asked in the introduction a theoretical framework will be presented in this chapter. The theoretical framework consists of theory about global warming, life cycle assessment, steel industry, Activity-based Costing, Discrete-event Simulation and input data management 2.1 Global warming The greenhouse effect is a process where the thermal radiation from the earth’s surface is absorbed by the atmospheric greenhouse gases and bounced back to the surface of the earth. Increases in concentration of greenhouse gases in the atmosphere have lead to what is referred to as global warming. Global greenhouse gases due to human activities have grown with 70 % between 1970 and 2004. Since the early 20 th century the Earths average temperature has increased by 0.8°C and about two thirds of the increase has occurred after 1980 (Climate change synthesis report 2007). 2.1.1 Greenhouse gases There are several gases that contribute to the greenhouse effect. The most significant are:  Carbon dioxide (CO2)  Methane (CH4)  Nitrous oxide (N2O) Each of these have different ability to reflect thermal radiation back to earth and also different residence times. Because of the different residence times it is impossible to find a measurement to compare greenhouse effect potential of the gases without defining the time horizon. (Lashof, Ahuja 1990) The GWPs are therefore calculated with different time interval, commonly 20, 100 and 500 years. The residence time is not always known and therefore the values should not be considered exact. GWP is expressed as a factor of carbon dioxide, which has a GWP of one as per definition. See Table 1 below with GWP calculations with different time interval for some common greenhouse gases. (Climate change synthesis report 2007) Greenhouse gas GWP value Common name Chemical formula 20 years 100 years 500 years Carbon dioxide CO2 1 1 1 Methane CH4 72 25 7,6 Dinitrogen oxide N2O 289 298 153 CFC-11 CCl3F 6730 4750 1620 Carbon Tetrachloride CCl4 2700 1400 435 Methyl Chloroform CH3CCl3 506 146 45 Table 1 GWP values for some greenhouse gases (Forster et al, 2007). 6 2.2 Life Cycle Assessment Life Cycle Assessment (LCA) is a systematic tool to evaluate the impact on the environment of a product, process or activity. LCA takes the whole life cycle in to consideration, from cradle to grave (Curran 2004). It includes material extraction, manufacture, usage and end of life. An LCA does not only consider CO2 but all kinds of environmental emissions such as atmospheric emissions, waterbourne wastes, solid wastes etc. See Figure 2 below. The principles and framework for conducting an LCA is described by the International Standard Organisation (ISO), in ISO 14040. In the ISO framework there are four steps to conduct an LCA described in ISO 14041-14044. ISO 14041 Goal and scope definitions – Define and describe the product, process or activity. Establish the boundaries and the context in which the assessment is to be made. Find which environmental effects will be reviewed. This is an important phase and will have a strong influence on the result. ISO 14042 Inventory analysis – Identify and quantify air emissions, solid waste disposal and waste water discharges. This stage is described in ISO 14042. ISO 14043 Impact assessment – Assess the potential effects of the releases identified in ISO 14042. ISO 14044 Interpretation – Evaluate the results from the inventory analysis and the impact assessment. Consider the uncertainties and assumptions used to generate the results. (Rebitzer et al 2004). Raw material acqusistion Manufacturing Use/resuse/ maintanance Recycle/Waste management Raw material Energy Inputs Outputs Atmospheric emissions Waterbourne wastes Solid wastes Coproducts Other releases System boundary Figure 2 Input, output and system boundary in an LCA 7 Figure 3 Life Cycle Assessment Framework - phases of LCA (Rebitzer et al 2004). According to Curran (2004) LCA faces three key barriers. 1. Lack of awareness of the need to look holistically at the overall impacts of actions. 2. Difficulties finding reliable and publicly available data. 3. Lack of an agreed upon life-cycle impact assessment model. 2.3 Steel industry Iron is a common element in our environment and essential for many living things. Most of the iron is compound in the crust of the earth as magnetite (Fe3O4) and hematite (Fe2O3). Iron takes part of a natural cycle where it transforms through different compounds. When iron is removed from natural steel cycle and processed to steel it enters into the technical steel cycle. The steel is then manufactured into a product and when that product is used up or in another way consumed it can be recycled and made into new products. There are two ways for the steel to exit the technical steel cycle. It could be too polluted with other materials to be used in existing industry processes or it can go back to the natural steel cycle through corrosion (Widman 2001). Today about 35-40 % of all steel is produced from recycled steel. To produce steel from recycled material is a an easier and less energy consuming process than using iron ore. To produce one ton of steel from iron ore consumes 23 GJ while only 7 GJ is consumed to make the same amount out of recycled steel (Widman 2001). It is difficult to find figures for the national recyclability for steel cans and even if it were possible to find these it would be impossible to separate Emballator’s product from the rest. However World Steel Association (2011) has calculated that about 68 % of steel cans where recycled in 2007 worldwide. According to SOU, 62 % of all steel was recycled in 1999 (SOU 2001 – 102). The figures from SOU are calculated as recycled steel divided by the amount of steel products produced that year. Interpretation Goal and scope definition Inventory analysis Impact assessment Direct applications:  Product development and improvement  Strategic planning  Public policy making  Other Other aspects:  Technical  Economical  Market  Social 8 According to Jernkontoret's research on the steel cycle, a lot of the application and products using steel, such as bridges and cars, are used for a much longer time, than for instance a can, before they are recycled. If the median time until recycling, for steel products, is twenty years the amount of steel recycled that year should be compared to the production of steel products twenty years ago. Since the total production of steel today is higher than it was twenty years ago it is impossible to reach 100 % by using the same calculations as SOU (Ekerot 2003). 2.4 Ecolabeling Ecolabeling is attracting more and more companies who see this as an essential factor to consider in their industrial and commercial strategies. In 1998 and 1999, ISO standardized ecolabeling practises and adopted the ISO 14020 series in which three different types of ecolabels are proposed (Lavalle & Plouff 2004). 2.4.1 Type I - Environmental labeling Type I environmental label is standardized by ISO 14024 and the goal is to identify overall environmental performance of a product or service within a particular product or service category. This performance should be based on life cycle considerations. Many countries, including Sweden has adopted this environmental labelling type. Al type I labels include two steps. First a committee of the ecolabel program establishes a set of minimum requirements needed to obtain the label. The second step is that companies are given a certification to use the label on products that fulfil the requirements (Lavalle & Plouff 2004). 2.4.2 Type II - Self declared environmental claims Type II environmental label is standardized by ISO 14021 and describes the environmental claim as an “environmental declaration made without certification from an independent third party, on the part of manufacturers, importers, distributers, retailers or any other entity able to gain benefit from this declaration”. The goals for type II of environmental labels are to promote environmental performance, to reduce inaccurate claims, to decrease confusion, to facilitate international trades and to allow customers to make informed decisions (Lavalle & Plouff 2004). In the ISO standard a set of requirements are established which must be followed. These requirements say that the information must be accurate and not misleading. It also says that the information must be true for the finished product as well as it must also take the life cycle into account. This is to identify a potential increase in an environmental impact pursuant to the decrease in another (Lavalle & Plouff 2004). Frequently used terms in this kind of declaration are:  Compostable  Degradable  Designed for disassembly 9 2.4.3 Type III – Environmental declaration Type III product declaration is described in ISO 14025. The declaration consist of environmental information such as percentage of recycled material, information on toxic substances and other information about a product´s environmental impact on a simplified performance report card. This declaration does not usually contain comparative claims but the information in the declaration may be used for such a comparison. If the information should be used for comparative claims the ISO standard 14040 must be followed (Lavalle & Plouff 2004). The information on a type III environmental declaration must be based on procedures and results from a quantified life cycle assessment compliant with ISO 14040 standards. For many small and medium size businesses a complete life cycle assessment is too expensive and requires too much time investment (Lavalle & Plouff 2004). 2.5 Activity-based Costing ABC is a financial method to assign costs of activities or resources in an organization to all products or services based on the actual consumption by each. In ABC two types of costs are identified. These are:  Direct costs – Costs that can be traced directly to a product or service. Examples of these costs are material costs and machines that are only used for one product.  Indirect costs – Costs that cannot be traced directly to a product. These costs are also called overhead costs. Examples of these costs are resources used for more than one product or services such as forklifts and heating of facility. To get the true cost for each product or service the indirect costs has to be divided among the products or services manufactured. Cost drivers are identified to distribute the indirect costs. It is important to identify the correct cost driver and this is sometimes difficult since there may be several causes for one indirect cost. (Skärvad and Olsson 2008) 2.6 Discrete-event Simulation Discrete-event Simulation (DES) is used to model the real world or a conceptual idea that is to be built or created in the real world. The models are often built in the image of production systems where the need for testing before implementing is needed or where system/process improvement is needed. DES can also be used to improve other areas such as healthcare, military or service sectors (for example hospitals and restaurants). The difficulties of predicting how a system of processes will behave and how they dynamically affect one another is one of the benefits of using DES (Banks 1999). Traditionally Banks method is used when working with a simulation project, there are several steps included. Two of the steps are especially relevant for this project and are discussed in more detail in the two following subchapters. For further reading and information about the other steps and on Banks method please see Banks (1999). 10 2.6.1 Demands on input data for a traditional DES project There is variety of issues concerning input data for DES projects. One in particular is the time aspect. According to Skoogh and Johansson on average 31% of project time is spent on input data management and according to and Trybula (1994) between 10 and 40%. The variations in time depend on the share of each category of data that needs to be collected. Following Robinson and Bhatia (1995) example one can divide the data into three different categories (Table 2). Category Type of Data A Available data B Not available but collectable data C Not available and not collectable data Table 1 (Robinson & Bhatia 1995) Category A represents already available data such as previous time studies or from automated logging systems. Category B represents data that needs to be collected for example through time studies. Category C is neither available nor collectable and needs to be estimated. The estimations have to be carefully done for the sake of the model quality. Depending on the data composition in terms of the three categories time spent working with the data differs. Only 7 % of companies have all data available for DES projects (Skoogh and Johansson 2007). Perera and Liyanage (2000) identified the major causes of inefficient data collection, these are:  Incorrect problem definition  Lack of clear objectives  High system complexity  Higher level of model details  Poor data availability  Difficulty in identifying available data sources  Limited data handling capacity For further reading on major causes of inefficient data collection see Perera and Liyanage (2000). According to Skoogh and Johansson (2007) the most time consuming activities are:  Data collection  Mapping of available data  Data analysis and preparation. In addition their study showed that only 20 % of DES projects finished their input data management according to set plans. The reason for this is that the company where the DES project is performed often overestimate the usability of the data or is unfamiliar with what type of or amount of data that is generally needed in DES projects. This leads to unforeseen work because of re-evaluations, calculations and additional measurements (Skoogh and Johansson 2007). The quality of the model is dependent on the quality of the data, which increases the need for efficient input data management. As the amount and complexity of the data grows so does the need for structure and order in the input data management (Skoogh and Johansson 2008). 11 2.6.2 Input data management method Skoogh and Johansson (2008) developed a structured methodology for the input data management process. The methodology consists of 13 steps, see figure 4, and is a tool to decrease the time and secure the quality of the data management. The method is especially important for those with limited experience of DES projects (Skoogh and Johansson 2008). A. Identify and define relevant parameters. B. Specify accuracy requirements. C. Identify available data. D. Choose methods for gathering of not available data. E. Will all specified data be found? No F. Create data sheet. Yes G1. Compile available data. G2. Gather not available data. H. Prepare statistical or empirical representation. I. Sufficient representation ? No J. Valid data representation Yes K.Validated? No L. Finish final documentation. Yes Figure 4 Input data management (Skoogh & Johansson 2008) 12 A. Identify and define relevant parameters As the headline implies one should identify and define relevant parameters with regard to project objective. It is important to take level of detail into consideration as well as the system complexity to find a appropriate compromise. This should be accomplished by getting to know the system through experienced personnel with system knowledge or company production technicians, or both. With more system knowledge it is possible to define how each parameter should be measured to best be represented in the model. When measuring it is important to define, when or where, to start and stop to the measuring (Skoogh and Johansson 2008). B. Specify accuracy requirements The purpose and objective of the projects together with the knowledge of the system to be modeled will have to be guiding when deciding which accuracy level is needed on the different parameters. A parameter with less influence on the result can be less detailed than one important for the result. This can at a later stage be approved or disapproved by a sensitivity analysis. Skoogh and Johansson (2008) recommend this for all borderline cases. To get a good representation of a process a lot of data needs to be collected. The more variability a process has the more data is needed, in case of processes that are fairly constant, such as robot cycle time etc, only enough data to rule out any unexpected variability is needed (Skoogh and Johansson 2008). C. Identify available data Identify which category (A, B or C in 2.6.1 Demands on input data for a traditional DES project) the desired data belong to, to make the most of all available data. In industry a lot of processes are measured and data collected, but not intended for a DES project. Therefore many companies believe they have enough and sufficient data for a DES projects when this is not the case. It is important to make sure that it is possible to collect the data and that it is on the right form or possible to get the correct form through calculations (Skoogh and Johansson 2008). D. Choose methods for gathering not available data Some of the data in DES projects are almost always not available, either category B or C. In the case of category B data case time studies, video recordings and other types of data collection is necessary. When time studies are made with stopwatches and similar it is important to define where the process measured starts and ends as described in step A. Identify and define relevant parameters, this is especially important if several people are measuring. Category C data is most common in not yet existing processes or systems and needs to be estimated with care. Time studies and video recordings of existing similar processes can be used for these estimation (Skoogh and Johansson 2008). E. Will all specified data be found? “Found” in this step refers not only to finding data but to make sure the data satisfies the demands made in the previous steps B, C and D. If the demands, such as number of data points, data accuracy or data quality are not satisfied problems may occur further down the line. According to Skoogh and Johansson (2008) step I and K are 13 especially vulnerable to this and would result in less quality model. If the demands cannot be fulfilled, the need for future iterations is likely F. Create data sheet Skoogh and Johansson (2008) recommend that a data sheet is created where all raw data as well as all analyzed data is kept. It is discouraged to keep the analyzed data in the interface spreadsheet and the raw data in a temporary document. This less structured method is more time consuming since there is a possible risk of data loss (Skoogh and Johansson 2008). G1. Compile available data The category A data is collected as specified in step C and the amount of data specified in step B. Usually the data needs to be processed and additional efforts made to sort, filter, calculate and convert the data to a desirable form. This to prepare the data for the coming statistical or empirical representation in step H. If the data is previously analyzed it need only be validated as described below in step K. (Skoogh and Johansson 2008). G2. Gather not available data In this step the focus is to make category B or C data category A (Robinson and Bhatia 1995). Category B data that is to be collected is a time consuming task (Skoogh and Johansson 2008), especially if they are gathered from a low frequency system or the product variability is high (high cycle time variability or long cycle time). Time studies on operators are controversial and this is usually solved with video cameras. However this means a doubling in real time measurements to collect data. To gather category C data is less time consuming. Category C data should to the furthest extent be based on assumptions and estimations made by a process expert or highly knowledge of the system. Gathering category C data can be time consuming if it is based on similar systems or processes or historical data (Skoogh and Johansson 2008). When both step G1 and G2 are done it is possible to move onto step H. H. Prepare statistical or empirical representation For the data to be implemented in the simulation model the raw data prepared in G1 and G2 need to be represented by statistical or empirical distribution, traces or bootstrapping (Robinson 2004). I. Sufficient representation? In this step the distributions from step H. are evaluated. There are several ways to do this, for example with a goodness-of-fit test. Goodness-of-fit test can be difficult to pass for large number of samples. Skoogh and Johansson (2008) suggest graphical comparison of the representational and original data. This given that the accuracy requirements regarding level of significance are fulfilled (step B.). This can be ensured at a later stage with a sensitivity analysis for the parts where less satisfying results are present for the graphical comparison (Skoogh and Johansson 2008). 14 If the accuracy requirements are not fulfilled, iteration from the steps G1 and G2 might be necessary. In the worst case scenario the iteration has to start at step B, which could have significant repercussions for the simulation model (Skoogh and Johansson 2008). J. Validate data representation According to Sargent (2010) lack of data validation is most commonly the reason model validation fail. It is also a costly and time consuming process. A validation of the data can save time and further iterations during the model validation (Skoogh and Johansson 2009). It is a difficult process to attain adequate validation quality data. The difficulties lies with the fact that the data for the conceptual model and project is based on is the same data it will be validated against (Sargent 2010). Both Sargent (2010) and Skoogh and Johansson (2008) recommend structure in the data collection process as the best guideline to avoid validation problems. Skoogh and Johansson (2008) recommend that to reach a good enough validity the data collection process should be performed alongside discussions with process experts. A final check is also advised towards the end where the data is reviewed in a structured way. K. Validated? When the data is validated it is ready to be incorporated in the model. The validated data can still cause problems in the model validation. If this problem occurs it is important to reevaluate the data to find the reason for the problem. Skoogh and Johansson (2008) conclude that a lot of the problems occur due to miscalculations in step H but that the problem might stem as far as choice of gathering method, step C and D. (Skoogh and Johansson 2008). L. Finish final documentation This entire method for data input management is focused on documentation, therefore most of the data should at this stage already be documented. To facilitate further studies and future projects as well as maintaining the validation some additional documentation is needed, such as (Skoogh and Johansson 2008):  Gathering methods  Sources of data  Validation results  Assumptions made This should be compiled in a data report and complete data sheet (Skoogh and Johansson 2008) 15 3. Method 3.1 Description of the EcoProIT method EcoProIT 2010-2013 is an ongoing project in the Product and Production Development department at Chalmers University of Technology (Chalmers PPD). As a step towards this master thesis goal, the method used is the EcoProIT method. Parallels can be drawn between this method and Banks method traditionally used for DES projects but there are some important differences. For more information about Banks methodology, see Banks (2004). Among other things Banks model does not facilitate the verification and validation of environmental aspects (Banks 2004). The description below of the EcoProIT model is a summation from unpublished documents by the EcoProIT project. 16 2. Concept 3. Collect data 4. Data to information transformation 5. Modelling 6. Verify the model Traditionally 7. Validate the model Traditionally 8. Verify the environmental calculations 9. Validate the environmental calcualtion 10. Analyse the model 12. Implement into organization 11. Report Good and enough information? Need more information? Verified? Validated? Sensitivity analyse Consumption validation, Reviews Good enough? Calculation and assumptions ok? Concept model, Pre-data collection Logic definitions, detailes specification 1. Set up project Set goals, system bounderies, functional unit, etc. Figure 5 The EcoProIT method 1. Set up project The goal definitions are a crucial part of a project, when these are set satisfactory the goals will help decide the level of detail for the project. They will be useful when defining the system boundaries for the environmental analysis. As a result of the system boundaries and the goals it is possible to define the limitations of a project. 2. Concept A conceptual model is a schematic showing the system logic and flow. To develop and verify this, close collaboration with the people in day to day contact with the real system is needed, discuss all assumptions made. The conceptual model develops throughout the project to coincide with the level of detail needed to fulfil the previous set goals. The system boundaries are clarified. A part of creating a conceptual model 17 and moving forward in the project is to define where and what type of data that has to be collected. The concept phase and data gathering is closely linked. 3. Data gathering With the conceptual model as a base it is possible to identify the data needed for the model. The data can be categorized as process data, material data, energy consumption data and energy content data. Process data: Logged data, interviews and measured data, much like in a traditional DES project. Material data: What materials are used, material histories, solvents paints etc. Energy consumption data: How much electricity, Liquefied petroleum gas (LPG), oil, compressed air is consumed etc.? Life Cycle Inventory (LCI)-data: Emissions for the electricity used, LPG content etc. It is possible to gather data and start building the structure of the model simultaneously although, it is necessary to gather some amount of production data before it is possible to start with the model. This is a step towards a complete conceptual model and important not to make unnecessary mistakes (or waste time). 4. Transformation of data to information Usually data straight from a log or measured cycle time need to be filtered, sorted, calculated converted etc. before it can be used in the simulation model. It is useful to represent information, energy and production flows etc. schematic as a complement to the conceptual model. This step includes calculating the different distributions necessary to create a dynamic model. Is the Information enough to implement the model? This question should be possible to answer with the help of the goals and the conceptual model. If the answer is no, more data need to be collected. 5. Modelling The model can be built with software specially developed for DES models or with ordinary languages such as C++. It is important that the code is structured and built in layers with a traditional DES as a foundation and the environmental aspects built as the outer layer. This will facilitate both verification and validation at a later stage as well as make the simulation model more flexible (Banks 1999). 6. Verify the model traditionally The verification ensures that the model is working as the conceptual model, following its logic laws etc. It is also done to ensure that the code is running correctly, no infinity loops etc. The verification of the code is closely connected to the modelling since the verification needs to be done continuously through the modelling. 7. Validate the model traditionally To validate a model is essentially to make sure that it corresponds to reality. It is also essential to be able to trust the models final result enough to use it for an analysis. 18 There are a number of steps that can be taken to ensure this. Through historical data validation, does the model perform according to realty with historical input data compared to historical output data? Does the model perform according to reality during extreme conditions such as breakdowns, overload or under load of the system? A Turing test can be performed, output data from reality and output data from the model is compared by someone familiar to the system. 8. Verify the Calculations for Environmental Impact It is important to make sure the model level of detail corresponds to the goals set. This is done by a sensitivity analysis. A sensitivity analysis makes sure that the data, from the sources that have the most impact on the products, is detailed enough and modelled in corresponding level of detail. An analysis should be performed on the sources that together stand for 80% of the GWP impact. 9. Validate the Calculation for Environmental Impact To validate the environmental part of the DES let a certified reviewer review/validate the analysis. It is possible to compare the result to similar products with similar analysis, keep in mind the different methods (dynamic static and so on) and differences. Another possible way to validate is to compare a cell’s or process’ used consumables to the same in the model. It is important to define the limitations for the analysis and document these together with the analysis. Otherwise the environmental impact analysis becomes invalid (changes etc.). 10. Analyse and use the Model The model is analysed so that the current state is known. This is important when evaluating the different improvement suggestions modelled. 11. Communicate the Results When all experiments and analysis are done and documented the information regarding and answering the projects goal should be compiled. The correct information should be communicated to correct stakeholders. 12. Implementation in organisation The EcoProIT method is still under development and has not yet defined guidelines for how to implement in organisation. The thought is to be able to use both the production analysis and production changes to also see how the GWPs are affected. The case study in this master thesis is a part of the development of the EcoProIT method. 3.2 Method for evaluating the EcoProIT method Evaluation of the EcoProIT method has been done continuously throughout the master thesis work. To have an organized workflow of the evaluation an affinity diagram has been made. This is also called the KJ-method after its originator Jiro Kawakita. Below is the method described as by Bergman and Klevsjö (2003).  The first step is that all kinds of ideas and thoughts are written down on small cards or “post it” notes. Preferably this is done in brainstorming sessions. It is important that everyone is allowed to have his or her say. 19  All notes are gone through to make sure that everybody agrees on what the text says. If necessary new notes are written that better represent the essence.  The notes are then placed in different groups. There may be notes that do not fit together with any other notes and these are then called “lone wolves” or “vagrants”.  A headline is decided for each group. The headline should in some sense sum up the group.  Arrows are drawn between the groups to illustrate the relationship between the groups. The arrows are moved around until the group members agree that they describe the connections correct. Some adjustments had to be made to the method to fit the purpose of this master thesis. Since the ideas and thoughts have come up during the whole project time the affinity diagram has been improved and reworked continuously throughout the project. Discussions have also been held with members of the team working with the EcoProIT project. 20 2. Concept 3. Collect data 4. Data to information transformation 5. Modelling 6. Verify the model Traditionally 7. Validate the model Traditionally 8. Verify the environmental calculations 9. Validate the environmental calcualtion 10. Analyse the model 12. Implement into organization 11. Report Good and enough information? Need more information? Verified? Validated? Sensitivity analyse Consumption validation, Reviews Good enough? Calculation and assumptions ok? Concept model, Pre-data collection Logic definitions, detailes specification 1. Set up project Set goals, system bounderies, functional unit, etc. Analysis of input data managment Comparison of time consumption Analysis of traditional verification and validation Identify possible errors and difficulties with environmental verification and validation A. C. B. D. Identify problems with the EcoProIT method Possible solutions EcoProIT method Figure 6 Method for evaluating the EcoProIT method 21 The focuses of the evaluation were, in accordance with the objective, input data management and verification and validation. These two areas are closely linked and one affects the result of the other which is represented in Figure 6. The evaluation have at times spilled into other areas as well, these have been presented if they are relevant for the EcoProIT method or connected to the focus areas mentioned in the problem formulation. When step three was reached in the execution of the EcoProIT method the time consumption of the environmental part of the input data management were documented for future reference. This step is represented by arrow A in Figure 6. There are several projects performed evaluating for example time consumption (Skoogh and Johansson 2009) and input data management (Skoogh and Johansson 2008) on DES projects. In combination with the theory gathered and previous experience of DES projects a comparison was made. It was possible to compare the time spent collecting and processing data in this project with the evaluations previously done. The analysis of the input data management depends in part on the data validation and the general input data management method used in the EcoProIT method, represented by arrow A in Figure 6. It also depends on the result from the verification and validation analysis (and error identification and difficulties). Therefore the analysis cannot be completed without feedback from this part. This is represented by arrow D in Figure 6. In turn the analysis of the verification and validation depend on the result from the Input data management analysis, represented by arrow B in Figure 6. When the analyses were done, their combined result highlights problems within or relating to the focus areas. Solutions where sought for these problems. The result of this evaluation will be a time chart and identification of possible errors. The analyses will be presented in chapter 6. Analysis together with suggested improvements to the EcoProIT method. 3.3 Conduction of the EcoProIT method In this chapter a description of how the EcoProIT method has been implemented is presented. The result, the EcoProIT model, refers to both a DES model and an excel interface for GWP calculations. 3.3.1 Concept It is important to have a full understanding of the system before embarking on the simulation part of a project. In this master thesis the production flow is important, in addition the energy flow and the material flow is as relevant. Since the GWP is derived from all parts of the system each flow and their logic is necessary to get an understanding of the system. To visualize a conceptual model several softwares are available, in this master thesis Microsoft Office Vision 2007 (Visio) was used. In Visio it is possible to create several different types of schematics both for business and administrative flows and maps, as well as engineering flows. To get a good overview of the system the production leaders explain how and where the products and its components were transported and processed throughout the factory. Blueprints of the factory were also used to get a better understanding of the 22 flow. For the understanding of all the energy sources and resources used, the facility manager gave a thorough description of the energy flow in the factory. The description also included information about some of the processes such as the enamel and printing press ovens and the effect of solvents on the temperature in these. When the conceptual model of the production and material flows was created the production leaders could verify it. The energy flow created was verified by the facility manager. As a step towards a complete conceptual model the system boundaries are set in accordance with the master thesis goals and clarified together with the schematic flows of the factory. In the real system large stock are kept as buffers between the departments. Because of this the ordering system had to be studied carefully to be able to interpret this into the model. The enamel and printing press processes where the ones thought to cause the most impact and was focused on for collecting data. The reason for this is the use of liquefied petroleum gas (LPG) and the burning of the enamel in the ovens. Therefore all the above aspects (material, energy consumption, production process) were taken into consideration. 3.3.2 Data gathering Expert fit was used to find the statistical distribution for a collection of data points, at times empirical data was used. Data gathering should be as objective as possible and should observe the process without affecting it. Methods often used are filming, interviews, observing, time studies etc., see chapter 2.6.2 Input data management method. In this master thesis the existing production data was used as far as possible. At Emballator the production process can be uneven i.e. planned stops on the chosen line, hardly any setup on day to several setups and failures the next, depending on the customer demand and material. This made time studies diverse and data points difficult to collect. The production data was therefore complemented and validated with interviews and observations, see chapter 2.6.2 Input data management method. Several types of data that was gathered, therefore the approach differed. Some data was easily accessible in the production lines process systems, some had to be filtered, sorted, calculated converted etc, and others were measured. To make sure all parts of the facility where included data was gathered mainly for the year 2011, some of the earlier data does not include new additions to the factory and building (latest added 2009). 3.3.3 Modelling The model was built with a software license that was available to the master thesis, AutoMod 12.3.1, which is based on a general purpose simulation language. A special purpose simulation language will generally have fewer errors than that of a general purpose simulation language. On the other hand the opposite is valid for flexibility (Sargent 2010). The EcoProIT method is new and unfamiliar and therefore the choice of software was decided so that not to cause unnecessary work or disruptions to the schedule. Because of its flexibility AutoMod is well suited for modelling a factory as well as the phantom parts of the model keeping track and calculating the environmental aspects. The production part of the model was built first and divided into sub processes according to the conceptual model. Each part was modelled separately and thereafter 23 added to the final model. This minimizes the time spent correcting errors in the entire code as well as simplifies the verification and validation process (Sargent 2010). By using load specific attributes in the model the loads created could be specified according to gathered data described in chapter 3.3.2 Data gathering. These specifications could be number of cans in one order, size of can, number of enamel layers, type of bottom etc. With the help of the attributes the loads move through the system as the real steel sheets, these are divided into cans at the same part in the system that the real cans are created. For the environmental part, attributes where also used to calculate the time each load spent in the different processes, keep track of number of plastic layers etc. This together with the more process specific attributes would then act as a basis for further calculations on GWP. The GWP calculations were done using excel where sheets with relevant process data, material data, LCI data and distributing calculated the GWP values for materials and processes using different excel algorithms. 3.3.4 Verify the model traditionally Verification is necessary to make sure the model is behaving according to the logic of the conceptual model and that no logic choices are missing in the model. Verification of the model is also to make sure that the simulation language is used in the correct way. This is possible to accomplish is several ways for example by structured walkthroughs, trace, input output relation and using the software debugging option (Sargent 2010) One should keep in mind that errors that occur can be caused by the data, conceptual model or other factors regarding the program or software (Sargent 2010). Verification of the model was continuously done while modelling. This to make sure not to build on something that is already faulty and minimize time spent searching for errors. By tracking entities throughout the system errors where made visible and possible to correct. Tracking was in this case done by printing messages in different parts of the process. The AutoMod debugger is also helpful when tracking or in general verifying the program. By sending single loads or very high number of loads through the system errors could also be detected and corrected. When printing the attributes (cycle time etc) to excel, errors or unreasonable times were a good indication of errors in the code. 3.3.5 Validate the model traditionally Validation is important to make sure that the model behaves according to reality or reflects that part of reality that is modelled to a satisfactory extent. In context of the conceptual model it is making sure the conceptual model corresponds to reality (Sargent 2010). When the data collection were made some of the data were saved, others were not applicable. Several of these could be of use for the system validation. For example number of cans produced per shift and utilization of the processes. The time spent in the different processes are important from a GWP stand point, therefore these were viewed as especially important to validate. The excel sheet were the process times etc were printed were useful when validating. The cycle times that were printed served as a good validation point and data for several orders could be compared to the real 24 system. The loads could be traced through the system and distributions and empirical representation could be validated (Sargent 2010). Where insecurities in the data or the model where discovered a sensitivity analysis where performed. This could help validate which factors are important from a GWP perspective. 3.3.6 Verify the calculations for environmental impact The EcoProIt method is still under development and there is limited literature or instructions for verification of the environmental aspects. The LCI data were therefore collected and chosen together with master thesis supervisor, Jon Andersson, and its examiner, Björn Johansson. The material requirements were filled to as large extent as possible and where LCI data were missing substitutes were found that satisfied the requirements as far as possible. When collecting environmental data from the production system it is handled with the same procedure as the ordinary production data. Therefore also going through the same validation process. The data collected and measured by the electrician is assumed to be correct. To verify that the calculations are correct the GWP excel sheet where thoroughly inspected. This was done continuously as it grew and simultaneously as the excel sheet with the AutoMod result was tested and verified, to make sure the units corresponded. The data was also compared to see if the values were reasonable in relation to each other. As described in 3.1 Description of the EcoProIT method a sensitivity analysis should be performed on the sources that together stand for 80% of the GWP impact 3.3.7 Validate the calculations for environmental impact The results from the model should be compared to similar products keeping different methods in mind. No LCA data has been found, therefore this is not possible. The result has been internally reviewed by three people. 25 4. System description In this chapter a description of the production system is presented. The description is complemented with an account of the information and energy flow. These three parts together represent the conceptual model that has been the base during this master thesis. 4.1 Information flow The sales office establishes a contract between Emballator and a customer. These contracts handle questions about size, appearance and number of cans. The contracts can also regulate other commitments such as an obligation for Emballator to keep a safety stock of finished cans. After a contract is established one or several orders for cans will arrive to Emballator in accordance with that contract. There are two kinds of contracts.  Short term contract. Usually the customer is obligated to buy the specified quantity within a year. When the quantity has been shipped the contract have to be renewed.  Long term contract. The contract specifies a yearly quantity. The first order of a contract is delivered within 15 days, but the following parts have a five days delivery guarantee. This means that large quantities of printed sheets are stored in the printed sheet buffer awaiting customer orders. Emballator have recently started contacting customers if their printed sheets have been in the buffer for more than a year. The customers are then obliged to either order cans or hire the storage area. The contracts are sent to the production planning office. A rough planning for the enamel and printing process is done by the planning office for the needed quantity. Depending on the size of the contract the production planning office may divide the contract into two or more printing operations. This is done in order to keep the stock of printed sheets down. This planning is made in SAP and will trigger an in house order to the printing and enamel office. Adjustments of the rough planning from the planning office are made in the printing and enamel office to keep the set up times to a minimum. For example, batches with the same size, colour or enamel is done after each other to reduce the set up times. Orders for cans arrive to the production planning office. When planning the sequence of the order set up times as well as priority is taken into consideration. This means that the operators are not allowed to change the sequence of the orders without first asking the production leader. This is because the operators do not know if the can order is make to stock order or if the customer is already waiting. 4.2 Production flow The cans produced at Emballator are produced in eight different lines. Each production line produces cans with a certain upper and lower diameter. The height of each batch of cans can be varied meaning that the volume of the cans can be changed at each line. The production line focused on in this master thesis is called 180-1 which produce cans with an upper diameter of 180mm and a bottom diameter of 168 mm. In this line five different volumes is produced; 2,5l, 3 l, 4l, 5l, and 6l. The production flow can be seen in figure seven below. Descriptions of the different processes will follow, as well as a description of the important buffer areas used within the facilities. 26 Figure 7 Flow for the 180-1 cans. Enamel Paint Machine Printing Press Raw Material Storage 1. Surface Treatment1. Surface Treatment Enamel Paint Buffer Printed Sheet Buffer Punch Deep Drawing 3. Ears Punch Deep Drawing 4. Handles Flow 180-1 Cut Shape and weld Seal and temper Tapering Role top and bottom edge Attach Bottom Attach ears Attach handle Seal Pressure test Temper Cooling Buffer Robot palletizing Cooling Buffer 2A. Main Production line2A. Main Production line Punch Role 2B. Bottom Production Gumming Temper Punch Role 2C. Lid Production Gumming Temper Storage for finished goods 27 4.2.1 Surface treatment The surface treatment is illustrated in step 1 in figure 7. 1. Metal sheets in different sizes, depending on which size of can will be produced, are transported to Emballator and stored until needed. 2. The metal sheets are transported by forklift to the enamel paint machine. There are approximately 22 different types of enamels that can be used in the enamel process. The sheets go through the enamel paint machine at least one time. Depending on whether the sheets should have enamel paint on one or two sides and which enamel paint that should be applied, it may be necessary to run the sheets through the enamel paint machine two or three times. Every cycle includes: o One coating operation o Heating in oven to harden the enamel o Cooling transport 3. After the enamel paint machine the sheets are stored in a buffer next to the enamel paint machine. 4. Depending on the customers' needs the sheets can be printed in a printing press. The printing operation consist three stages. o Two color printing operation o Heating in oven to harden the color o Cooling transport It is possible to apply two colors each run through the printing process. For some prints it is necessary to run through the printing process up to eight different times. On average there are 4.2 colors in each print. After the printing process the sheets are transported by forklift and stored in a buffer until needed. 4.2.2 Main production line The fully automated main production line is illustrated in step 2A in figure 7. 5. The sheets are transported with forklift from the buffer to the can machine. The steps in the can machine are: o The sheets are cut to desired size depending on the height of the can. Each sheet is now corresponding to one can. o The sheets are welded to a cylindrical shape. To make sure the weld damage does not compromise the seal of the can, enamel paint is applied at the seam. The cans are thereafter tempered and transported on a conveyor that works as a cooling buffer. o The cylinders are made conical by applying pressure to the upper part of the cylinder. o The cans are tapered and the top rim is gradually folded to get the desired height and profile of the rim. The can is then turned upside down, to achieve the desired profile on the bottom rim, also by gradually folding the edge. o The bottom is attached by folding the rim. 28 o The ears are attached the cans by spot-welding them to the sides of the cans. o The handles are thereafter attached to the ears. The handles are unrolled and shaped at a sub flow to the main line, here the plastic grips are attached to the handle of some orders of cans. o Enamel paint is applied to the welding points of the ears. o A pressure test is performed to make sure the cans performance is satisfactory. o The cans go through an oven to harden the enamel paint at the welding points. o After the oven the cans are cooled on a conveyor belt and then packed by a robot to a pallet. 4.2.3 Post production 6. The pallets are picked up by an automated guided vehicle (AGV) and transported to a station where the pallets are covered with plastics. 7. After step 7. the pallets are transported with a second AGV to third AGV that transport them to the storage area for finished goods. Here they are picked up by a forklift and transported to the right place. 8. Soon before the truck comes to pick up the pallets they are moved from their place in the storage of finished goods to an area at the pick up place. 4.2.4 Lid production The lid production line is illustrated in step 2C in figure 7. 9. The raw material for lids is metal sheets and these are surface treated with enamel in the same manner as step one, two and three above. On rare occasions they also go through the printing operation in step four. There are several kinds of lids to meet all kinds of customer needs. Emballator uses several different fully automatic lid machines and three of these are used for production line 180-1. o The metal sheets are transported with a forklift to the lid production machine. o Round pieces are punched out of the metal sheet in specific pattern to reduce waste. o Depending on what kind of lid that is produced the lids are rolled in different steps to the finished shape. o A rubber is placed on the side that will be in contact with the can to make sure that the lid will be able to retain he substance in the can. The rubber is liquefied when applied to the lid but will soon harder to a rubber. o When the lids are finished they are they are packaged and transported to the storage area for finished goods. 29 4.2.5 Bottom production The bottom production line is illustrated in step 2B in figure 7. 10. The bottoms are produced in the same manner as lids. As for the lids there are different types of bottoms to meet the customers' needs. The only differences in the production flow between the bottom production and he lid production is that when the bottoms are finished they are stored until needed at the main production line. 4.2.6 Ear production The ear production line is illustrated in step 3 in figure 7. 11. There are two sizes of ears used at Emballator depending on the size of the cans. Both kinds are produced in the same way in similar machines. The cans produced in the 180-1 production line uses the smaller size of ears. o The steel for the ears arrives to Emballator on rolls and stored in the Raw material warehouse. o When the rolls of steel are needed a forklift transfer the ear production line transports them. o A fully automatic machine produces ears in the following steps: o Round pieces are punched out o Every piece get a hole in the middle that the gripping wires later can be attached to. o The pieces are deep-drawn to a small cup. o The machine spits out the finished ear to a container. o The container is picked up by a forklift and stored until needed at the line. 4.2.7 Buffer and storage areas According to Emballator's purchaser the raw material storage that contains about 9000 tons of steel (as of February 2012) and the maximum capacity (to not take up space intended for other purposes) is between 6000-6500 ton. Emballator's desire is to lower the inventory level in this area. The high raw material inventory is partly due to long lead times and insecurities in deliveries, since the raw material is purchased from Asia. In comparison to the raw material buffer there is a small buffer area for the sheets processed in the enamel machine. These are processed regardless of order and works similar to a safety stock so that the printing machine always have available sheets. In the printed sheet buffer every contract has its own space, and every customer can have several contracts. There are also buffers for ears, bottoms, lids etc. Because of the buffers one process does not have to wait for products from another process earlier in the production flow. 30 4.3 Energy flow Emballator uses electrical energy, LPG and solvent in the enamel as energy sources. Emballator uses LPG for heating the facility. Since the ovens at the printing process, enamel process and after the welding operations at the can production line generates heat to the facility Emballator only need to heat the facility during the winter. When the average outside temperature for day and night is above four degrees the production at Emballator is enough to keep room temperature inside the facility. Because of the Swedish climate no cooling of the facility is needed. Finished Can Transportation Enamel paint process Printing press process Forklift AGV Oven LPG Solvents Electricity Electricity Enamel paint machine Enamel paintElectricity Compressed air LPG Solvents Printing press PaintElectricity Compressed air Oven Electricity Electricity Main production line Electricity Compressed air Oven 1 LPG Electricity Oven 2 LPG Electricity Enamel paint Cooling water Lid Bottom Ears Electricity Compressed air LPG Electricity Electricity Compressed air LPG Electricity Electricity Electricity Electricity Electricity Figure 8 Energy flow at Emballator 4.4 Data gathering and data to information transformation Much of the process data were available through the process computer systems used by the production leaders and operators. It was necessary to evaluate the data from a quality perspective. Discrepancies where dealt with by discussing with production leaders and assumptions were documented for the future model. There were also unstructured interviews with operators responsible for the processes. 4.4.1 Process data The enamel machine and the printing press are to a large extent used by products bound for other production lines than that of 180-1. The data not regarding 180-1 was used to find distributions for order sizes, number of incoming raw material, number of printing rounds and number of enamel layers etc for non 180-1 lines. The different lines where not differentiated but treated as one type of sheet and can. Data for the enamel paint machine was retrieved from the machines stop log data for 2011. This included stops, failures and set up times. In the collected data all stops were marked with a cause, i.e. set up time, kind of failure or service action. During the interviews the operators explained that they did not always label the stops with the correct description (i.e. setup marked as failure and vice versa), due to inadequate information. Therefore to a large uncertainty was present to separate the setup time 31 from the failures. Because of this the distribution for mean time to repair (MTTR) includes set up times and the distribution for the mean time to failure (MTTF) represent the time to failure or set up. The stop times in the enamel process and the printing process are considered as indirect costs since the stops are assumed to be related to the machine and not because of the nature of the order. To distribute the GWP contributions due to stops, the total time of all stops for each process was summed up and divided with the total number of sheets that had gone through the process during the same time frame. Each sheet is then given a GWP contribution that is divided among number of cans, bottom or lids that sheet will later becomes. Since the set up times in the enamel process is not possible to separate from the stop times these GWP contributions were also distributed as overhead costs. The stop log for the printing press for 2011 was collected. This include order number for each order, number of times that order had gone through the printing operation, start and end time for each order, start and end time for set up and start and end time of stops because of failure or service. Stops for adjustments or failures in the middle of an order are not recorded. From the collected data the distributions for MTTR and MTTF for the longer stops between orders and set up times could be calculated. To find all short stops, such as minor adjustments, not recorded in the collected data, the speed in sheets per minutes where calculated for each order and then distribution was found. The system to record set up times and stop times, in the 180-1 production line, is considered too complicated by Emballator's employees and is not in use. Therefore it was not possible to find data points for MTTR or MTTF. Instead the time recorded for quality checks for every thousand can were studied. From this data it was possible to find the time between the first quality check on one order, to the first quality check for the next order. From the times between these time points a rate of cans per minute was calculated. In this way the set up and failure times are included in the cans per minute data. Distributions for batch sizes up to 1000 cans, 1001-2000, 2001-3000, 3001-4000 and above 4000 cans were calculated. This separation of batch sizes was done in order to make the set up times more proportional to the number of cans. The data for the lid, bottom, ear and plastic wrapping machine were not considered as important as for the enamel paint machine, printing press and production line. This assumption would have to be validated in the sensitivity analysis. Data for the lid and bottom machines were collected by estimations by operators. The ear machine and plastic wrapping machine were observed for a couple of minutes for estimations of the cycle times. 4.4.2 Material data Both the mass and specification of content for each material used in production were needed. Some materials, such as plastic handles, are optional and for these materials the share of orders with and without these options were also needed. The amount of each material was collected from SAP. Plastic handles and wrapping plastic are not specified in weight but only pieces per can and length. For these materials a physical example was collected and weighed. 32 It is difficult to find out the exact content for each material. Most of the chemicals are only labelled with the suppliers name and the material safety data sheet only mentions components that are toxic or flammable. Since it would not be possible to find LCI data for supplier specific products, estimations based on the material safety data sheet were considered good enough. Blueprints of the metal sheets were studied to find the exact amount of steel used for all cans. Also the wastes due to the cutting of metal sheets were retrieved from these blueprints. The raw material sheets used for the 6l can are used for other products as well. There are no data available regarding how the 6l sheet is used among other can sizes. The blueprints show a large amount of scrap for the 6l cans. In reality the production use the scrap for other cans as well as using the sheet for other cans when there is a lack of the correct raw sheet. 4.4.3 Order, contracts, transportation and buffer data To find a distribution for batch sizes, data from can production line with reported cans per shift were studied. The contracts divisions into suborders depend on the size of the contract and the customer. The larger the contract the more sub-deliveries, this is usually the case there are of course exceptions. Some contracts stay in the system for a long time sometimes up to a year or more. Because of the contract system it was not possible to find sufficient historical data to support this representation. The data could not be validated and a simplification for the order system had to be made. This simplification is based on the call offs of produced cans statistic. A sensitivity analysis will have to ensure if this is a good enough representation. The sensitivity analysis will also have to rule if the differences in time in buffer because of this simplification have a significant impact on the final model. The theory behind this problem is acknowledged in the theory chapter 2.6.2 Input data management method. To find the distances for transportation of materials to Emballator the purchaser at Emballator named the cities from where the materials are shipped. Google maps and Eniro were used to find the distances from each supplier. Materials shipped from Asia are assumed to be shipped by boat to Göteborg and then shipped by truck to Emballator in Ulricehamn. Shipments from Europe (not including Sweden) are assumed to be shipped by train to Göteborg and then shipped by truck to Ulricehamn. All shipments from Swedish suppliers are assumed to be shipped by truck. Efforts were done trying to find the dynamic of the storage areas. Data from 2011 for the raw sheet buffer, buffer for sheets with enamel, buffer for printed sheets, buffer for finished cans and buffer for bottoms were collected and analysed. The raw sheet buffer data contained information about incoming and outgoing parts for each sheet size. Since the batch sizes are quite large only a few points of data for each sheet size were available. The buffer for sheets with enamel contained information about incoming and outgoing amounts for each kind of sheet with each kind of enamel layers. At most, twelve data points were available for each kind of sheet. 33 Data for the buffer for printed sheets were collected using SAP. Since the sheets in the buffer for printed sheets are custom made for each kind of can the data contained information for incoming and outgoing sheets for each kind of can. Due to the high variety of products it was not possible to draw any useful conclusions. The data collected for the buffer of finished goods contained information of incoming and outgoing amount of cans for every month. Due to the high variety of products it was not possible to draw any useful conclusions. The data collected for the buffer of bottoms contained information about the incoming and outgoing amount of each bottom type for each month. At most, twelve data points were available for each kind bottom. 4.4.4 Energy consumption The energy sources at Emballator are electrical energy, Liquefied Petroleum Gas (LPG) and compressed air. The compressed air is produced by compressors using electrical energy. The electricity consumption for the entire factory is available at the owner of Ulricehamn's power distribution grid. It is measured by the hour. To complement this data Emballator's electrician was able to help with consumption measurements throughout the flow, as well as the forklift batteries/chargers and the compressors producing he compressed air. It was not possible to measure the consumption of compressed air at each place where it is consumed. Instead the facility manager looked at the efficiency of the compressor at a given time when he knew which machines that where active. From this data he could estimate the share of the consumption. The consumption of LPG for heating the ovens at the enamel paint machine and the printing press machine could be collected by observing sensors near the ovens. Attempts were done trying to find the stoichiometry for the combustion of solvents in the enamel and LPG in the enamel process and the LPG in the printing press process. During the autumn of 2011 Emballator exchanged their utility unit, and therefore also their energy source for heating the facilities, from oil to LPG. The consumption of LPG is very much associated to the outside temperature. About twenty data points of LPG consumption could be found and together with temperature data from Sveriges Metrologiska och Hydrologiska Institut (SMHI) an equation could be calculated for the LPG consumption depending on the outside temperature. The equation shows that when the average outside temperature for one day and night rises above 4°C no LPG is consumed for heating the facility. This is because the ovens at the paint machine and enamel paint machine produces so much heat to the rest of the facility. 34 4.4.5 Distribution factors Distribution factors for distributing overhead GWP contributions was calculated by analysing blueprints of the sheets together with number of cans produced for each can size during 2011 and number of cans per pallet for each can size. The distribution factors were calculated both for each can size and for each can production line.  Share of pallets produced  Share of cans produced  Share of metal sheets consumed  Share of weight consumed  Share of cutting waste Also, the blueprint of the facility was studied to find the share of the total area for storage of finished goods, can production line, raw material buffer and so on. The working hours during 2011 for enamel paint machine, printing press and can production line were calculated by analysing data for reported cans or metal sheets. By looking at times the number of shifts at each resource was counted. If there had been any activity during one shift it was assumed that the resource was running during the entire shift. After counting all shifts it was multiplied with the number of minutes for each shift. From the total number of minutes the share of an entire year was calculated for each resource. LCI data for steel, steel wire, enamel paint, alkyd, boat transport, truck transport, train transport, polyethane, polystyrene, production of LPG, combustion of LPG, water, electricity, where collected with support from Björn Johansson and Jon Andersson using SimaPro 7.3. GWP data were collected from Intergovernmental Panel on Climate Change (IPCC) Report of the Intergovernmental Panel on Climate Change 2007. For additional reading about the LCI and GWP data collected please see Appendix. 4.5 Model description The functional unit is the can and its lid, since the system starts with the raw material sheets so does the model. The large inventories on hand throughout the real system acts as buffers between the production processes. The effects the processes have on each other are decreased and in turn the dynamic between them. This is mirrored in the model and supported by the production technicians. The buffers reduces the dynamic in the real world as well as in the model. Each process is only dependent on itself and its breakdowns and setups. The order data is based on the call offs, made when delivering cans, as mentioned in 4.1 Information flow. The order numbers for the cans correspond to the bottoms and lids. The order gets a specification in the beginning of the code which decides what type of bottom and lid. The specification also give number of enamel layers, printing press rounds, speed in 180-1, plastic handle or not, number of plastic packaging layers etc. These factors decide how and how fast the loads move through the processes. 35 4.5.1 Enamel process There are four steel sheets processed for 180-1 production line, these in turn have between one and three enamel layers. All 22 type of enamels or their thicknesses have not been modeled, instead an approximation of one, two or three layers in combination with the four different sheet types have given 12 different types of enameled steel sheets. Nr of Enamel Layer Type of steel sheet 1 2 3 4 1 1 2 3 4 2 5 6 7 8 3 9 10 11 12 Table 3 The different combinations of sheets and enamel. The enamel machine and the printing press are to a large extent used by products bound for other production lines than that of 180-1. The data compiled about non 180- 1 was used to model loads to simulate not available time in the enamel machine and printing press. By this the printing press and enamel machine would be dynamically occupied by non 180-1 sheets. These loads where discarded after the printing press since there is no processes where the 180-1 and other lines share processes after the printing press. The printed sheet buffer accommodates sheets to all lines, but to simulate Emballator's entire product variation in the model is not within the scope of the project. 4.5.2 Printing press Each printing round gets a cycle time and a setup time, a distribution decides whether a failure or maintenance time is appointed to that printing round. Since the print on the can is customer specific a similar simplification as in the enamel process has been done for the sheets processed in the two color printing press. The sheets processed in the printing press intended for the 180-1 line are printed between one and seven rounds. This results in 84 different combinations of sheets. Since the printing press can handle two colors the one and seven rounds correspond to between 1 and 14 colors, there is no historical or other data supporting any assumptions on the number of colors. Nr of printing rounds The different enamelled sheets 1 2 3 4 5 6 7 8 9 10 11 12 1 1 2 3 4 5 6 7 8 9 10 11 12 2 13 14 15 16 17 18 19 20 21 22 23 24 3 25 26 27 28 29 30 31 32 33 34 35 36 4 37 38 39 40 41 42 43 44 45 46 47 48 5 49 50 51 52 53 54 55 56 57 58 59 60 6 61 62 63 64 65 66 67 68 69 70 71 72 7 73 74 75 76 77 78 79 80 81 82 83 84 Table 4 Different combinations of enamelled sheet and printing press rounds 36 4.5.3 Can production line In the 180-1 line the setup and failure time is included in the cycle time, by that logic a larger order has a higher speed per can than a small order. This is specified in the beginning according to order size. The raw material sheets are cut into the metal sheet creating the body of the can. This is represented in the model by cloning the load into the same number of pieces.