DEPARTMENT OF TECHNOLOGY MANAGEMENT AND ECONOMICS DIVISION OF SUPPLY AND OPERATIONS MANAGEMENT CHALMERS UNIVERSITY OF TECHNOLOGY Gothenburg, Sweden 2025 www.chalmers.se Warehouse automation in the construction material and lumber industry A case study of the Swedish company Derome Bygg & Industri AB Master’s thesis in Supply and Operations Management FRANS BRÄUTIGAM ADAM VIKTOR STJERNSTRÖM ERIKSSON Warehouse automation in the construction material and lumber industry A case study of the Swedish company Derome Bygg & Industri AB FRANS BRÄUTIGAM ADAM VIKTOR STJERNSTRÖM ERIKSSON Department of Technology Management and Economics Division of Supply and Operations Management CHALMERS UNIVERSITY OF TECHNOLOGY Gothenburg, Sweden 2025 Warehouse automation in the construction material and lumber industry A case study of the Swedish company Derome Bygg & Industri AB FRANS BRÄUTIGAM ADAM VIKTOR STJERNSTRÖM ERIKSSON © FRANS BRÄUTIGAM, 2025 © ADAM VIKTOR STJERNSTRÖM ERIKSSON, 2025 Department of Technology Management and Economics Chalmers University of Technology SE-412 96 Gothenburg Sweden Telephone + 46 (0)31-772 1000 Cover: This thesis presents a framework for selecting suitable automation technologies in construction material logistics. The framework is designed to help decision-makers identify automation opportunities that match operational characteristics and strategic priorities. Key insights and recommendations are presented in Chapter 5 Gothenburg, Sweden 2025 Warehouse Automation in the Construction material and lumber Industry A case study of the Swedish company Derome Bygg & Industri AB FRANS BRÄUTIGAM ADAM VIKTOR STJERNSTRÖM ERIKSSON Department of Technology Management and Economics Chalmers University of Technology SUMMARY Suppliers of construction materials face an increasing demand for efficient logistics operations, while the use of automation in their supply chains remains limited. A key challenge lies in the bulky and heavy nature of construction materials, which complicates handling and automation. This study investigates how Derome Bygg & Industri AB (DBI) can improve their logistics through implementation of automation in picking, packing, and loading operations. A mixed-methods approach was employed, including interviews with DBI logistic managers and operational staff, on-site observations, analysis of historical company sales data, and a literature review focusing on warehouse design, automation, and Industry 4.0 technologies. Empirical data was also collected from suppliers of automated equipment. The study examines DBI’s current operations and develops a categorisation of product groups suitable for automation. Several technological solutions were found suitable to DBI’s context. The analysis indicates that wooden planks and sheet materials offer the greatest potential for efficiency gains through automation. The findings provide practical implications to support DBI’s future investment decisions and contribute to a broader understanding of warehouse automation strategies in the construction material sector. . Keywords: Warehouse design, Construction material warehousing, Industry 4.0, Automated picking, Picking construction materials, Automated loading, Internal logistics ACKNOWLEDGEMENTS We would like to express our sincere gratitude to our industrial supervisor, Mathias Hansson at Derome Bygg & Industri AB (DBI), for his dedicated support and valuable guidance throughout this thesis project. His commitment and willingness to share insights have been greatly appreciated. Further on, we are also thankful to the entire team at DBI for their openness and generosity in sharing their time and knowledge with us. Every conversation has contributed meaningfully to our understanding and the development of this work. We would further like to thank our academic supervisor, Altahir Hassan Irshien Ali, at Chalmers for the continuous support, encouragement, and constructive feedback. We also extend our thanks to other faculty members and staff at Chalmers who have taken the time to assist us during this thesis. Lastly, we would like to thank our families and friends for their patience, encouragement, and support throughout this intense and rewarding journey. Frans Bräutigam & Adam Stjernström, Gothenburg, April 2025 Table of Contents List of Figures List of Tables 1 Introduction ............................................................................................................ 1 1.1 Background .................................................................................................... 1 1.2 Problem Statement ......................................................................................... 2 1.3 Aim & Objectives .......................................................................................... 3 1.4 Research Questions ........................................................................................ 4 1.5 Scope & Limitations ...................................................................................... 4 2 Literature Review................................................................................................... 6 2.1 Industry 4.0 in Logistics ................................................................................ 6 2.2 Warehouse Design ......................................................................................... 7 2.3 Picking ........................................................................................................... 8 2.4 Loading .......................................................................................................... 9 2.5 Packing ......................................................................................................... 10 2.6 Automation .................................................................................................. 10 2.7 Summary & Knowledge Gap ....................................................................... 11 3 Methodology ........................................................................................................ 12 3.1 Research Design........................................................................................... 12 3.2 Literature Review......................................................................................... 13 3.3 Empirical data collection ............................................................................. 14 3.4 Data Analysis ............................................................................................... 17 3.5 Research Validity & Reliability ................................................................... 20 4 Results & Analysis ............................................................................................... 21 4.1 DBI’s current system and strategic goals..................................................... 21 4.1.1 Current picking operations ................................................................... 23 4.1.2 DBIs current assortment ...................................................................... 24 4.2 Sales Quantity .............................................................................................. 29 4.2.1 Assortment selection ............................................................................ 29 4.2.2 Baseline Sales Quantity and Number of Order Lines 2024 ................. 33 4.2.3 Sales Quantity and Number of Order Lines 2029 ................................ 35 4.2.4 Sub-category sales analysis.................................................................. 36 4.3 Automation Assessment............................................................................... 44 4.3.1 Automated picking of sheet materials.................................................. 48 4.3.2 Automated picking of planed planks ................................................... 53 4.3.3 Automated picking of thin steel profiles .............................................. 57 4.3.4 Automated packing .............................................................................. 58 4.3.5 Automated loading ............................................................................... 60 5 Discussion ............................................................................................................ 64 5.1 Key Findings ................................................................................................ 64 5.2 Practical Implications................................................................................... 64 5.3 Theoretical Contributions ............................................................................ 64 5.4 Social, Ethical and Ecological considerations ............................................. 65 5.5 Limitations of the Study............................................................................... 65 5.6 Future Research Directions .......................................................................... 66 6 Conclusion ........................................................................................................... 68 References .................................................................................................................... 70 List of Figures Figure 3.1: Illustrating the framework used for warehouse design. ........................... 13 Figure 4.1: Step 1 of the framework, understanding the current system & strategic goals. ............................................................................................................................ 21 Figure 4.2: An overview of DBI’s current logistic center. ......................................... 22 Figure 4.3: Schematic view of the picking process at DBI. ....................................... 24 Figure 4.4: Step 2 from the framework; define, obtain and analyse the data. ............ 25 Figure 4.5: Obtaining and analysing the data from the assortment. ........................... 25 Figure 4.6: Understanding the criteria to select the assortment. ................................. 29 Figure 4.7: The result of the assortment analysis. ...................................................... 31 Figure 4.8: Obtain sales data....................................................................................... 33 Figure 4.9: The first step of the data analysis of the sales. ......................................... 34 Figure 4.10: The framework shows the steps of future sales analysis. ....................... 36 Figure 4.11: The fourth step, to establish unit loads. .................................................. 37 Figure 4.12: The fifth step of the method, determining operating procedures and methods. ....................................................................................................................... 45 Figure 4.13: Illustrating the sixth step of the method in this study. ........................... 50 Figure 4.14: A high-bay storage and picking solution of sheet materials from Systraplan. .................................................................................................................... 51 Figure 4.15: A solution from Systraplan, where order lines can be consolidated on racks before being sent for packaging. ........................................................................ 52 Figure 4.16: A sheet material storage system, shown by Barbaric. ............................ 52 Figure 4.17: A multi-levelled solution for storing and picking sheet materials, shown by Barbaric. .................................................................................................................. 53 Figure 4.18: The figure is a modified screenshot of a video from the company Barbaric and shows an automated wood handling machine ........................................ 57 Figure 4.19: Tentoma. RoRo StretchPack® packaging machine. .............................. 59 Figure 4.20: Tentoma. RoRo StretchPack® packaging machine. .............................. 60 Figure 4.21: Tentoma. RoRo StretchPack® packaging machine ............................... 60 Figure 4.22: Illustration of how a conveyor belt can be used for loading. ................. 61 List of Tables Table 3.1: List of interviews and meetings for the master’s thesis project ................. 16 Table 4.1: DBIs assortment categories with respective most sold sub categories. IND (industry products) is excluded because the sales quantity of IND products is negligible...................................................................................................................... 26 Table 4.2: The table shows examples of DBIs categorization of popular SKUs ........ 26 Table 4.3: DBIs frequency classes. ............................................................................. 30 Table 4.4: The table shows what categories and frequency classes of DBIs existing assortment which will be included in the planned logistics center. X means that it is included and - means that it is excluded. ..................................................................... 31 Table 4.5: The table shows how the assortment selection in table 4.4 affects how many orders can be covered based on historical data. ................................................. 32 Table 4.6: The table shows the number of SKUs which are planned to be included in the logistics centre........................................................................................................ 33 Table 4.7: The table shows the historical sales quantity for 2024 for the warehouses Derome, Trollhättan and Mölndal................................................................................ 35 Table 4.8: The table shows historical data for the DBIs regional warehouses in Mölndal, Derome and Trollhättan combined. This data only considers the assortment selection described in Table 4.4. .................................................................................. 35 Table 4.9: shows the forecast for 2029 based on the historical data. .......................... 36 Table 4.10: The table shows the five greatest sub-categories sorted by sales quantity. ...................................................................................................................................... 38 Table 4.11: The table shows the five greatest sub-categories sorted by number of sales. ............................................................................................................................. 38 Table 4.12: The table includes the most sold sub-categories for each assortment category, sorted from highest sold quantity. It also includes the most sold product category for each sub-category. ................................................................................... 39 Table 4.13: The table includes the most sold product groups for every sub-category at DBI and the sales quantity and number of sales for these product categories. It also shows what sub-category and assortment category these product groups belong to. .. 40 Table 4.14: An evaluation of potential impact from automation of different sub- categories. .................................................................................................................... 46 Table 4.15: Only shows sales quantity for significant product groups. ...................... 49 Table 4.16: Specifying technical specifications of all the product groups in the planed pine and planed pine subcategories. ............................................................................. 53 Table 4.17: The range of technical specifications in the planed pine and planed spruce subcategories. An automated picking solution needs to comply with these requirements to be able to handle all materials in these subcategories........................ 57 Table 4.18: Evaluated dimensions from thin steel profiles. ........................................ 58 Table 4.19: Summarizing the findings of using a conveyor belt for loading (Carlan et al., 2023) compared with current state at DBI. ............................................................ 61 Table 4.20: Analysing how the loading process at DBI can be automated. ............... 63 1 1 Introduction This chapter introduces the context and motivation for the study. It begins with a background to the construction material industry and the challenges faced in its logistics operations. The chapter then presents the problem statement, followed by the aim and objectives of the study. Two research questions are defined to guide the investigation. Finally, the scope and limitations are outlined, specifying the boundaries within which the research was conducted. 1.1 Background Traditionally, businesses have prioritised cost reductions in manufacturing and other business areas. However, logistics has historically not been recognized as a strategic business function on its own (Rushton et al., 2022). In recent decades, the strategic importance of supply chain within businesses has increased. Industry 4.0 and emerging technology such as Internet of Things (IoT) and big data have enabled more comprehensive management of supply chain inputs and outputs (Yavaş & Özkan- Özen, 2020). Additional enablers of modern, efficient warehouses include technology advancements in automation, robotisation and digital communication. The adoption of these innovations enables potential to achieve significantly improved supply chain performance. Nevertheless, Patrucco et al., (2020) identify several challenges associated with implementing such technologies, particularly for the construction materials sector. Despite these challenges, recent technologies have proven essential for improved logistics performance and managing complexity in medium and large-sized enterprises. One of the companies that could benefit from advancing its supply chain in line with Industry 4.0 principles is Derome Bygg & Industri AB (DBI), a Swedish supplier of building materials and tools, mainly serving professional carpenters (M. Hansson, personal communication, January 20, 2025). DBI is part of the Derome group and is distinguished from its competitors by its vertically integrated supply chain. The company derives its name from its founding village, Derome. It operates its own production facilities, warehouses, vehicles and provides support and services to forest owners. Distribution is a core component of DBI’s operations. Customers can either load materials into their own vehicles at DBI’s warehouses or have the orders delivered by DBI directly to construction sites. At the current regional warehouse in Mölndal, customers load their vehicles in the same area where DBI prepares orders for delivery. However, the new warehouse (referred to as the logistics centre throughout this study) will be closed to customers and dedicated exclusively to distribution using DBIs own vehicles. One distinguishing characteristic of the building materials industry is the combination of short lead times, and diverse deliveries in terms of volume and weight (Patrucco et al., 2020). At DBI, deliveries are typically fulfilled the day after an order is placed, as demanded by its customers. This underlines the critical role of logistics in the company’s total cost structure and highlights the high potential return from logistics improvements. According to M. Hansson (personal communication, January 20, 2025), DBI recognises that developing a robust and responsive supply chain is essential in today’s competitive environment. As key competitors are investing heavily in restructuring their logistics operations, DBI seeks to retain their competitiveness. A revised logistics strategy is therefore seen as a key enabler for enhancing logistic performance, increasing profitability, and supporting long-term growth. As part of DBI’s logistics strategy, the company plans to establish a structure with central warehouses that supply logistics centres (M. Hansson, personal communication, January 20, 2025). The preliminary plan also includes connecting each logistics centre to a small number of hubs. These logistics centres are expected to support a range of activities, including storage, consolidation, 2 packing, and picking. Furthermore, the logistics centres are assumed to accommodate several types of building materials, such as those for residential construction, kitchen building, wooden decks, hardware store and workwear. DBI’s vision is to reach state-of-the-art level of operations, which includes implementing recent technologies to enable fast and flexible processes (M. Hansson, personal communication, January 20, 2025). Due to the wide range of stock keeping units (SKUs) in terms of shape and size, the operational complexity is considerable. As a result, several systems are expected to be integrated. The large number and variety of SKUs also necessitate careful storage planning, with different types of storage solutions required to meet diverse material requirements. Furthermore, since various types of vehicles enter the logistics centres, the loading operations must be adaptable to ensure efficiency. The logistics department of DBI is tasked with presenting a new warehousing and logistics strategy, which must be approved by the top management, including the CEO and logistics manager (M. Hansson, personal communication, January 24, 2025). The company has outlined strategic targets. By 2029, DBI aims to increase the sales volume distributed through its delivery service by 50 % compared to 2024 and improve its profit margin by reducing costs through more effective logistics operations. A key component in achieving these goals is the design and implementation of a new, efficient logistics centre. It is assumed that operational costs can be reduced by implementing a purposefully designed logistics centre. A key enabler in this effort is the use of automated technologies, which also can enhance productivity, revenue, and overall output (Hardy and Brougham, 2022). Additional benefits include fewer errors, improved ergonomics, and resilience. These benefits align strongly with DBI’s strategic requirements. 1.2 Problem Statement Efficient logistics is crucial to become competitive for construction material suppliers; however, the warehouse management remains low in adaptation of recent technology (Demirkesen & Tezel, 2022). This is also clearly noticed from DBI in practice (M. Hansson, personal communication, 20 January 2025). For companies, such as DBI, with operations characterised by short lead times and high customer requirements, in combination with a varied assortment, inefficient warehouse picking and loading are considerable cost drivers. Currently, DBI’s picking and packing operations are handled manually, which indicates that the staff must handle heavy and bulky products, such as plaster- and wooden boards. This results in a low picking frequency to avoid injuries. Lack of performance in this area risks driving costs and decreased service level to customers. In an interview with M. Hansson (personal communication, January 24, 2025), it was stated that the current picking operations at DBI have reach its full potential within the existing working method, indicating that new methods are required. Furthermore, based on real world observations of loading and unloading operations at DBI’s main warehouse in Mölndal, and from the interview with M. Hansson, the logistics responsible of DBI (personal communication, January 20, 2025), it becomes apparent that loading construction materials is time consuming. This is likely caused by the high complexity and varied goods characteristics. DBI has developed their manual processes to support efficient operations and high customer satisfaction, however, there are generally drawbacks of manual handling compared to automated handling. For example, manual handling can result in high personnel and operations costs, and decreased customer satisfaction, if the delivery precision is affected negatively. In addition, delays can occur because of inefficient operations. In this context and based on the literature and empirical data collected (more details in Results & Analysis chapter 4), picking and loading appears to have the largest impact on the overall logistics performance. Thus, the main focus in this study is on the picking and loading operations at DBI logistics centre. At DBI, the packing is performed by the 3 picker between the picking and loading process. Therefore, packing is also studied to ensure a complete process solution from picking to loading and avoiding bottlenecks related to packing. As previously stated, automation offers many benefits with a strong match to DBIs strategic requirements (Hardy and Brougham, 2022). The challenge is that there are also many barriers that must be overcome to gain these benefits, otherwise there is a risk of costly errors. The technical aspects are one of these barriers (Rathore et al., 2022). The challenge is that automated solutions are often designed to handle a specific job and lack flexibility in handling a diverse range of products. DBIs assortment vary widely in shape and weight and many different unit loads are used. Therefore, to enable automation the assortment was separated in different product categories, and these categories were then matched with suitable technology. Since not a single automated solution can be used for the whole assortment, an analysis of relative sales quantity corresponding to each product category was conducted to ensure automation is applied where it has the highest total performance impact. Automation within warehousing is addressed in previous research, with extensive literature covering areas such as picking technologies, storage systems, and overall system integration (Roodbergen & Vis, 2009; Boysen et al., 2019; Faccio et al., 2020). However, there is a notable gap in research within automation of large and irregular sized construction materials, such as wooden planks and sheet materials. Thus, there is a lack of knowledge about automated technology and its effect on performance and efficiency within DBI’s future logistics centre. To remain competitive, many businesses must face changes in their supply chain, which require decisions regarding investments and thorough planning before implementation. Even though there is much research about warehouse layout design in the literature, there is limited research within the area of construction materials. In the article from Demirkesen & Tezel (2022), it is explained that in practice, automation processes within construction materials face a distinct set of challenges compared to other industries. Therefore, little is known regarding how automation processes and designs could fit into the requirements of different material categories in warehousing of the construction industry. Existing research within automation in warehouse design focuses on standardised and smaller products. Seidlova & Sourek (2010) addresses the challenge of designing warehouses for materials that are difficult to handle, like building materials, however it does not address automation. The issue of designing warehouses utilizing the technology of Industry 4.0 has also been addressed in previous studies (Yavaş & Özkan-Özen, 2020), however only a few studies have focused on the construction material industry. One study indicated that automation in the construction materials industry in Nigeria is underutilized, which implies increased cost and delays in delivery (Alumbugu et al., 2022). The underutilization could be caused by a lack of understanding in how to apply technology in this area. It can therefore be concluded that there is an apparent lack of knowledge in how to implement the automation in the construction material logistics, and to a varied assortment in general. 1.3 Aim & Objectives The aim of this study is to develop a better understanding of how automation can be utilised and implemented in warehouses in the construction material industry. According to Baker & Canessa (2009) and Yavaş & Özkan-Özen (2020), technology is crucial when designing a new warehouse. This study aims to contribute new insights in an area where knowledge is currently limited. To narrow down the scope, the study focuses on processes where the highest potential performance impact from automation could be expected. Previous literature indicates that picking drives most of the warehousing cost, and therefore this will be a focus of the study (De Koster et al., 2007). 4 The study addressed the categorisation of DBI’s assortment to identify the physical characteristics and logistical requirements of the products. An investigation and evaluation of feasible automation solutions was also conducted for picking, packing, and loading processes corresponding to the distinct product categories. Successful implementation of automation may be crucial for DBI, as the company are targeting a 50% increase in sales volume through its delivery services, combined with a reduction in logistics cost relative to revenue by 2029. By a clearly identifying which product categories are suitable for automation, this study aims to provide a decision basis for DBI’s future investments. In summary the objectives of this study are to: • Identify and categorise the SKUs within a construction material warehouse that are most feasible for automation. • Identify, evaluate, and match suitable automated solutions for picking, packing, and loading processes based on the selected SKU categories. 1.4 Research Questions As a logical consequence of the problem statement and aim of the following research questions was defined. RQ1: What SKU categories in construction material warehouses are most suitable for automation, and for which of these categories do automation offer the greatest potential improvement in overall warehouse performance (productivity, cost-efficiency, and quality)? From the literature it appears that automation may bring benefits that strongly match the strategic goals of DBI (Hardy and Brougham, 2022). However, automated solutions are often highly limited in their ability to handle a varied assortment; therefore, the problem becomes deciding what product categories are suitable for automation. RQ2: In what ways can automation be implemented within the picking, packing, and loading processes of a construction material warehouse, specifically targeting the SKU categories identified as most suitable? After identifying the product categories most suitable for automation, the subsequent challenge is to determine suitable technical solutions that align effectively with these specific categories. 1.5 Scope & Limitations The study focuses on the aspects of warehouse design that have the greatest impact on overall logistics performance. The authors initially intended to examine all processes and SKU categories at DBI, the scope was later narrowed down to enable a more in-depth analysis of selected, relevant aspects of warehouse design. Given the time constraints of the study, the analysis is limited to the automation of picking, packing, and loading processes within the logistics centre. Although order receiving and returns handling are essential, they are not a within the scope of this study. The geographical scope of this study was limited to the Gothenburg area; however, the logistics centre may potentially be replicated into other regions, if DBI decides to. The preliminary service area for the logistics centre is between Strömstad and Halmstad. The optimal placement of the logistics centre, transport solutions, financial considerations, and data handling were not within the scope of this study, as these aspects would require extensive geographical analyses which is beyond the core subject of internal logistics. Furthermore, the influence of the central warehouse and the hubs on the logistics centre was not addressed. 5 The authors aimed to prioritise the investigation of the processes and product groups where improvements would lead to the greatest total performance impact. Detailed economic analyses, such as return of investments and budgeting, were outside the scope of this study. However, the sales quantity analysis and the focus on the most resource-intensive processes aimed to investigate automation where it has the highest potential for cost savings and performance improvements, ensuring a cost-effective design from the bottom up. Another limitation is that a detailed analysis and comparison of specific automation technologies was not conducted due to time constraints and limited data availability. While such an investigation would have added value, the study still contributes new knowledge to the literature, as the topic has not previously been explored in this context. Considering the logistics centre and the proposed automated solutions, the focus has been on the overall concept and the material flows rather than on detailed technical specifications. Due to insufficient reliability of the available sources for certain automatic technologies, these have deliberately been excluded from the analysis. This decision was made to maintain a high validity and reliability of the study’s conclusion and recommendation. Regarding the technologies used for picking, loading, and packing, the emphasis was placed on exploring general concepts rather than conductin a detailed evaluation or comparison. The limitations imply that the results and conclusions of the study are specifically tailored for DBI’s requirements and assortment and may not be generalisable to companies with different product mixes or operational conditions. 6 2 Literature Review The purpose of this literature review is to present a theoretical background to warehouse design by explaining how Industry 4.0 can be implemented in a warehouse that is providing construction materials, and to identify research gaps connected to picking, packing, and loading of various construction materials. Furthermore, literature on the implementation of automation is presented. And finally, a summary of the literature review is made together with findings of research gaps. 2.1 Industry 4.0 in Logistics The Fourth Industrial Revolution, Industry 4.0, was introduced in Germany in 2011 to enhance the country’s industrial competitiveness through increased digitisation of manufacturing processes (Kagermann et al., 2013). While Kagermann et al. (2013) introduces the concept of Industry 4.0, Lu (2017) focuses more on the technical integration of physical and digital systems. Industry 4.0 includes merging physical and digital environments via advanced information technologies, such as Internet of Things (IoT), big data, and artificial intelligence (Lu, 2017). This makes it possible to connect machinery, people, and systems in real time, and thereby creating more flexible, efficient, and data-driven value chains. Further on, Kagermann et al. (2013) explain a key component of Industry 4.0, which is cyber-physical systems (CPS), where computer systems interact with physical devices in the supply chain, such as warehouses, factories, and vehicles. Physical objects can be equipped with sensors and communicate with other devices in a network to provide real-time data. Yavaş & Özkan-Özen (2018) in contrast, focus specifically on the role of Industry 4.0 in logistics. It is emphasized that the use of CPS and 4.0 technologies in logistics can streamline information and resources in the supply chain to enhance efficiency and lower the costs of producing customized products. A crucial enabler for industry 4.0 is the real-time data availability. Zhong et al. (2017) describe how IoT-based technologies facilitate real-time monitoring and information sharing across supply chains, providing greater transparency and operational efficiency. Radio-Frequency Identification (RFID) is a core IoT application, enabling accurate tracking and tracing of materials throughout the supply chain. Zhong et al. (2017) stress the role of real-time transparency across the supply chain, whereas Lee et al. (2017) discuss the design and application of an IoT-based warehouse management system for smart logistics and argue that it can increase accuracy and efficiency in picking. Robotics is a key part of modern material management, and through Industry 4.0, Automated Guided Vehicles (AGV) has been introduced for internal material handling and is described in Wang (2016). AGVs can move material between inbound, storage locations and outbound, without human interaction. This can increase both the efficiency and the flexibility in warehouses. Further on, Wang et al., (2016) describes industry is heading towards smart material flows, where the products can communicate with and guide machines. This indicates that a palletised product with a sensor can give a signal to a robot that it is ready to be moved to the next station, decreasing the requirement for manual instructions. According to Wang et al. (2016) the result of IoT and robotics in materials management include increased efficiency, reduced errors, increased productivity and savings. While Wang et al. (2016) examine fully automated systems such as AGVs, Chemweno and Torn (2022) highlight the utility of collaboration between humans and robots. Moreover, Chemweno and Torn (2022) claims that heavy lifts or monotonous tasks can be reduced through modern collaborative robots, or also known as “cobots”, that work together with humans, side-by-side, and thereby flexibility can be increased. As a conclusion, robotics enhance efficiency within material handling where real-time data and automation cooperate. In conclusion, Industry 4.0 technologies, including IoT, CPS, robotics, and real-time data integration, offer significant potential to transform logistics operations. By adopting these technologies, 7 warehouses can achieve higher efficiency, better accuracy, and greater operational flexibility, which is critical for industries with complex supply chains, such as the construction material sector. These technologies are highly relevant to the development of DBI’s logistics operations. 2.2 Warehouse Design In parallel to the evolution of Industry 4.0, warehouse design principles have also developed to address the growing complexity of modern supply chains. In Jones et al. (1997) Lean Logistics is described as identifying and eliminating non-value-added activities, while newer paradigms like Smart Logistics, explained by Lee et al. (2018), utilize real-time data to optimize inventories, and according to Zhong et al. (2017), anticipate demand fluctuations. A foundational approach is provided by Baker & Canessa (2009), who propose a structured step-by-step methodology for designing warehouses, from determining business requirements to finalizing equipment selections and workflows. By integrating lean thinking and advanced digital tools, warehouse design can more effectively respond to volatile demand, improve material handling efficiency, and maintain cost- effective operations in an Industry 4.0 landscape. In warehouse design, research generally define the central processes as receival, put away, storage, picking, packing, and shipping (Tompkins et al., 2010; De Koster et al., 2007), illustrated in Figure 2.1. Construction materials can be more complex in material handling, since they often do not conform to typical unit-load configurations like palletised goods (De Koster et al., 2007; Kasim et al., 2013). Furthermore, Kasim et al. (2013) observe that many traditional or paper-based methods persist, leading to inefficiencies and difficulties in tracking items. De Koster et al. (2007) highlight that order picking implies high costs and labour intensive for warehouse operations. In the construction materials context the processes can vary, because of the complexity of large-scale and bulky items (e.g., lumber, or heavy building materials). When comparing De Koster et al. (2007) and Kasim et al. (2013), both identify inefficiencies in warehousing but Kasim et al (2013) focus on the drawbacks of paper-based systems while De Koster et al. (2007) stress the resource intensity of picking operations. Figure 2.1: Illustrating the general process flow in warehouse design. Note. Retrieved and adapted from Baker & Canessa (2009) 8 The framework and tools for the various steps in warehouse design, as described by Baker & Canessa (2009), has been foundational for the analysis in this thesis. It was not followed exactly, instead it has been adjusted to suit this study and is illustrated in Figure 2.2. The first step of warehouse design is to define the system requirements (Baker & Canessa ,2009). This includes understanding the strategic role of the warehouse. The suggested tools to use for this includes using literature on supply chain strategy and scenario planning. Functions like cross- docking and storage are also considered. The second step is to define and obtain data and the tools used include gathering relevant spreadsheet data from the company database and using checklists to document the current processes (Baker & Canessa, 2009). The data to be gathered include product details, order profiles, goods arrival, dispatch, and cost. It is suggested to extract database data, consult with different stakeholders in the company and then summarize the data in a useful way. The third step includes analysing the data. The tools include spreadsheet models and visualizing the flows and processes of the warehouse. Specifically, SKU popularity distribution and demand, customer order profiles and inventory profiling can be analysed. The fourth step includes establishing the unit loads to be used and for this simulation or mathematical models are commonly used (Baker & Canessa, 2009). It is also suggested to consider the full supply chain and unit load constraints from suppliers. After this, the fifth step involves determining the operating procedures and methods. Moving on, the sixth step includes listing equipment types and their characteristics (Baker & Canessa, 2009). For this it is common to use spreadsheet models, simulation, or decision trees. Equipment can also be evaluated according to the scale of the operation and flexibility requirements. The equipment attributes are evaluated to ensure suitability for the application. Full cost analysis is also described. Further on, equipment capacity and quantities are calculated in spreadsheets. The expected impact on KPIs from implementing distinct types of equipment is analysed. This aims to provide a base for equipment selection. Figure 2.2: Step 1-6 of the warehouse design framework. Note. by Baker & Canessa (2009). 2.3 Picking Picking is typically one of the most labour-intensive and costly activities in warehouse operations, typically accounting for up to 55% of total operating expenses (De Koster et al., 2017). While Industry 4.0 technologies offer significant opportunities for improving warehouse operations it has still not been widely adopted in the construction material sector. Alumbugu et al. (2019) studied 9 manufacturing warehouses for construction materials in Nigeria and found a reliance on manual picking processes, limited barcoding, and minimal real-time data captured, which decreased service- level reliability. The results suggest that mechanized or partially automated solutions could improve the efficiency and reduce long lead times and high labour costs. Further on, automation may enable decreased prices on construction material and delivery delays. The lack of automation in construction material warehouses emphasized by Alumbugu et al. (2019) might be explained by the complexity of this industry as identified by Tompkins et al. (2010) who found that the relative complexity is high because of the large, heavy, and non-standardised items such as wooden planks and steel profiles. The challenging context identified by Tompkins et al. (2010) may also be a contributing reason why previous studies such as Fernandes et al. (2019) have focused on automation of smaller goods in a more standardised format. Previous studies have focused on handling small and medium sized boxes, however there are no studies found about planks or heavy lumber. Automated systems handling heavier and larger items with real-time data integration is not widely documented. This gap is particularly relevant for DBI’s operations, where a sizeable portion of the assortment consist of large and heavy construction materials. The requirement for improving picking efficiency, combined with the specific challenges of non-standardised building materials, highlight the importance of exploring new picking solutions. 2.4 Loading Carlan et al. (2023) researched if automated cargo loading and unloading brings benefits when both purchase cost and operational cost is considered. The findings indicate that increasing cargo volumes, increased labour costs and improved truck fill rate lead to a better Return on Investment (RoI) for automated solutions. Using forklifts in loading was compared to using automated loading technologies such as loading plate and transport belt. When comparing these technologies, the transport belt produced the best economic results when combining project cost and operational cost over a 10-year period. This is mainly because it reduces the costs associated with employees and energy usage. The other automated technologies however incurred a higher cost after 10 years compared to using forklifts. Carlan et al. (2023) researched the long-term cost implications of different automated loading system while Thylén et al. (2025) stress the importance of collaboration within the supply chain for successful implementation of automated loading. Thylén et al. (2025) researched the requirements for automated loading and unloading specifically for autonomous transport. It is stated that automated loading and unloading require close collaboration with the companies operating the loading bay and the trucks. Kembro and Norrman (2020) suggest that when implementing automated solutions new competencies are required from the employees. Technical skills for handling the automated loading and unloading systems become more relevant than manual loading and unloading. When contrasting Thylén et al. (2025) with Agrawal et al. (2023) both studies acknowledge the challenges in automated loading, however, Agrawal et al. (2023) provide a more detailed breakdown of the barriers to address for successful implementation. Agrawal et al. (2023) focused specifically on automation of loading and unloading for autonomous transport. It was indicated that the challenges and requirements which must be addressed for a successful implementation of automated solutions can be divided into five main categories. These include the physical characteristics of the load, the interaction with the information system, the transportation off and onto the trailer, securing and arranging the load to the trailer and the legal aspects. When considering the physical characteristics of the load the non-uniformity of goods must be managed to prevent damaging the goods and ensuring safety. The goods also must be arranged on the trailer in a way that ensures safe and legal weight distribution. Additionally, the non-uniformity creates challenges in automatic 10 detection of the goods weight, type, and size, which is required for correct loading. The interaction with the information system, automatic registering of goods, requires that the identifier tag is placed in the right location. Additionally, efficient communication between different information systems is required. Another issue is establishing clear boundaries on who is responsible for various stages of the loading and unloading. The information system should also be able to plan the optimal loading sequence of the goods. Another main area is moving the goods off and onto the trailer (Agrawal et al., 2023). An issue with this process is that the environment is constantly changing regarding people and goods in the loading area. This must be managed to avoid damage to equipment or people. The mix and interaction between automated and manual work also must be managed to ensure safety and efficiency. The height difference between the trailer and loading bay also must be addressed. The decision-making abilities of the automated system to be able to handle different situations is also described. Another area to address is securing and arranging the goods on the trailer. Optimum fill rate and goods safety can be challenging with automated solutions like AGVs. Correctly aligning the goods must also be addressed. The load must be secured and unsecured through automation. Finally, the legal aspects must be considered. One of the aspects is the traceability in various stages which is required to detect if the load is correctly secured and to detect when damages to the goods have occurred. There are also legal aspects regarding safety for employees in the loading area. Defining accountability in various parts of the process is also suggested. 2.5 Packing Efficient packaging and palletising are critical components of effective logistics operations, especially when handling large materials such as wooden planks or sheet materials. According to Szymonik (2016), well-designed unit loads improve transport, storage, and automation, while reducing damages and labour strain. For DBI, applying these principles to their packaging operations, could enhance flow efficiency, minimize manual workload, and lower operational costs. Szymonik (2016) emphasises that the formation of palletized unit loads should follow predefined procedures, considering factors such as the type and arrangement of packaging, pallet structure, transportation condition, and logistics labelling. 2.6 Automation Rathore et al. (2022) investigated barriers for implementing disruptive technologies in logistics. One of the technologies which was investigated was AI-based robots. The study claims that a diverse product range creates challenges for implementing automated AI robots. The varying product characteristics creates a technical challenge because the robots are not very versatile. The study claims that the Austrian logistics firm KNAPP AG found that the robots can only handle 15 % of the product range successfully. It is therefore not feasible to use one automated system to handle all the product range. Instead, multiple types of automated solutions adapted for the corresponding product types are required. Aside from the technical barrier, the study also found barriers for implementing disruptive technologies which include legal and regulatory framework, lack of top management support, resistance to change and infrastructure. While Rathore et al. (2022) focused on barriers for implementing disruptive technologies, Hardy and Brougham (2022) address the negative and positive effects of implementing automation. More specifically, Hardy and Brougham (2022) researched the impact, barriers, and enablers of automation in firms in telecommunications, energy, manufacturing, and media sectors. One of the identified benefits of automation includes increased productivity which enables higher revenue and work output. The second impact is cost savings. Thirdly, automation enables resiliency and continuity, robots can operate 24/7. Finally, another main benefit is improved data accuracy and reduced number of errors. One of the possible negative impacts from automation includes automation dependency of employees. While depending on the automatic system the employees’ manual skills 11 can erode which is problematic for operational adaptability. Secondly, automating bad processes creates escalated issues, rework, and inefficiencies. Thus, the findings indicate that there is a risk of magnifying underlying flaws through automation. Thirdly, automation can require regular maintenance and updates which can be costly if not managed properly The findings of Hardy and Brougham (2022) indicate that a key enabler of successful automation implementation is executive endorsement and approval, which is necessary to ensure prioritization, set direction and secure resources for the project. Secondly, IT infrastructure and involvement is required. It is foundational for automation projects as automated technology is commonly integrated with the IT system. The features of the automated system are limited to the features enabled by the IT infrastructure. Thirdly, process knowledge and mastery are emphasized. Knowing what process to prioritize and applying the automation correctly is emphasised to avoid costly errors and inefficiencies. Finally, resistance is identified as a barrier. This can be addressed by involving and engaging employees and front-line users in the project it is possible to build trust, leverage operational knowledge and support from the employees which is essential for a successful implementation. 2.7 Summary & Knowledge Gap The findings of the literature review suggests that Industry 4.0 is an enabler for a more efficient warehouse management and design. However, it is concluded that within warehousing of construction materials there are research gaps. For example, He & Turner (2021) suggest that little attention has been made within academia of recent technologies applied to warehousing of forestry products. Therefore, this study aims to contribute to academia by addressing the issue of how recent technologies within construction materials, particularly for forestry products, can be applied to warehousing. Further on, this theoretical review presents recent technologies. Within recent technologies of picking and packing within warehousing, little is found about handling construction material. Finally, the theoretical review highlights key considerations to be addressed for successful implementation of automation. These considerations are crucial when researching a field that is poorly studied previously. 12 3 Methodology The methodology is a mixed methods single-case study. Literature on the topic was systematically reviewed to build a theoretical foundation. The empirical data sources include semi-structured interviews, company presentations, and historical data analysis (e.g. spreadsheets of historical sales and assortment). To improve the reliability of the data, it was validated through reviews by stakeholders at DBI. 3.1 Research Design To address the research questions, a mixed-method, case-based approach was applied. This was chosen because of the practical, complex, and context-specific nature of the research, focused on the logistics operations of Derome Bygg & Industri AB (DBI). Creswell & Clark (2017) suggest using mixed methods when a single data type is not sufficient for answering the research questions. This justifies the choice of a mixed method for this study as analysing quantitative data is central for answering the research questions however qualitative data is required to guide the interpretation of this data and to understand the broader context and operations of DBI. This is also in line with Creswell & Clark (2017) who argue that mixed methods are recommended when the complexity of a real-world problem requires a nuanced understanding. Yin (2017) provides a framework for case study research. The framework justifies case study research when the focus is on a contemporary issue in a bounded system. Our study of DBI focuses on the contemporary issue of warehouse automation and conducts and in-depth exploration of DBI as a bounded system which justifies the case-based approach of this study. Cote (2021) distinguish between descriptive, diagnostic, predictive and prescriptive data analysis. Descriptive analysis creates the foundation other analysis is built on by visualising and summarising what is already known. Diagnostic analysis aims to establish cause and effect by studying what has happened. Predictive analytics are used to make predictions about the future based on analysing historical data and trends. Prescriptive analysis considers multiple factors to choose between different options using a data-driven approach. For RQ1: What SKU categories in construction material warehouses are most suitable for automation, and for which of these categories do automation offer the greatest potential improvement in overall warehouse performance (productivity, cost-efficiency, and quality)? First, a descriptive phase documented the current system using: • Quantitative data (historical sales data) • Qualitative data (semi-structured interviews and direct observations). This aligns with common practice in logistics research where quantitative data is used to analyse flows and capacities, while qualitative insights reveal context and operational complexity. Baker & 13 Canessa (2009) also suggest analysing SKU popularity distribution as a step-in warehouse design, this was conducted by quantitatively analysing the relative sales quantity for every SKU. Further on, the analysis followed a prescriptive approach for assortment selection using historical data. Subsequently, a predictive approach was applied to forecast 2029 material flows. Finally, the categorised flows were evaluated for automation suitability using a prescriptive framework. For RQ2: In what ways can automation be implemented within the picking, packing, and loading processes of a construction material warehouse, specifically targeting the SKU categories identified as most suitable? Building on RQ1, the relevant categories were studied using a descriptive approach to evaluate product characteristics and applicable technologies. Mixed data about the possible technology was then analysed using a descriptive approach. The product categories and their characteristics were also analysed using a descriptive approach interpreting mixed data. A prescriptive approach was then used to compare the findings about the technology and match this to the product characteristics to find the answer for RQ2. The research is structured according to the warehouse design framework by Baker & Canessa (2009), widely cited in logistics and warehouse planning literature, and illustrated in Figure 2.2. This framework supports a structured, step-by-step process for warehouse design, and was chosen because of its alignment with both academic standards and industry practice. Figure 2.2 summarises the research process for the different issues which have been investigated. Not all steps of Baker & Canessa (2009) were followed; instead, the study focused on steps 1–6, as illustrated in Figure 3.1, which emphasise strategic role definition, data collection, analysis, studying the product characteristics to establish unit loads, determining operating procedures, and technology evaluation. The reason for following these steps is that they encompass the scope of the research questions. By following these steps, it was possible to first establish the context needed for adressing the research questions. Further on, the method allowed finding the most suitable SKUs and processes for automation and pairing these with suitable technology and thus answer the research questions. Steps 6-12 of the framework focus on layout design, which is outside the scope of this study. Figure 3.1: Illustrating the framework used for warehouse design. Note. Adapted from Baker & Canessa (2009), adjusted to suit the context of this study. 3.2 Literature Review The literature review was conducted systematically to provide a comprehensive understanding of Industry 4.0 technologies, warehouse design principles, and automation challenges in the sector of construction materials. Knowledge of Industry 4.0 was further deepened through targeted research in 14 logistics. Insights into warehouse design were gathered through continuous information collection focused on the construction sector. The literature search strategy combined keyword-based searches and snowballing, following the approach recommended by Webster & Watson (2002). The keywords were used for searching in academic databases such as Google Scholar and Chalmers Library. The keywords contained combinations such as: • “Warehouse design” • “Logistic centre design” • “Industry 4.0 in logistics” • “Construction material logistics” • “Warehouse automation” • “Picking automation” • “Loading automation” • “Challenges in construction supply chain” • “Construction material warehousing” To ensure a balanced searching and finding relevant studies, boolean operators (AND, OR) were used for refinements. Studies made after 2010 were prioritised, however a few older yet significant and foundational works (e.g. Baker & Canessa, 2009; De Koster et al., 2007) were included. To find the current research trends within logistic centre design and warehouse automation, focused on heavy and large building materials, an iterative searching approach was utilised. After a relevant article was found, backward and forward snowballing were used. Backward snowballing, by using the reference list to find additional relevant articles. Forward snowballing, by searching for studies that have cited that article, to find more recent findings. The literature was collected and evaluated and thereafter categorised and prioritised based on its key areas and relevance for this study. In addition, relevant academic books were selected to provide a solid theoretical foundation for the empirical investigation. 3.3 Empirical data collection To develop a comprehensive understanding of DBI’s current operations, empirical data was gathered through a combination of interviews, observations, internal company data analysis, and websites of automation technology providers. From this, it was possible to identify feasible opportunities of improvements for the new logistics centre. Interviews were conducted with logistics managers and operational personnel at DBI to collect information on current challenges and future requirements. The interviews have followed a semi-structured approach, which allows flexibility and simultaneously covers the main subjects, such as picking routines, loading processes, warehouse capacity planning, and automation experiences. The list of interviews and meetings are provided in Table 3.1. Additionally, observations were made during a site visit at DBI’s production facility in Derome and regional warehouses in Mölndal, Derome and Landskrona, as well as the central warehouse in Landskrona. During these visits picking, packing, and loading operations were primarily observed, however bottlenecks, ergonomic challenges, and potential areas of automation were also addressed. Company data, such as historical sales volumes, stock levels, and assortment categorisation were collected and analysed through spreadsheets and pivot tables. This enabled quantitative analysis of sales quantity and frequency categorisation. 15 When collecting data for answering RQ2, the prioritised sources were academic articles, which provided insights about automated packing and loading. However, it was found that little research had been conducted about automation of picking in this field. Thus, other sources were needed to be able to answer RQ2. Google was used to scan the market for automated technologies in this field. The keywords which were used were: 'warehouse automation for construction materials,' 'automated picking for heavy items,' 'automated loading,' 'automated picking of sheet materials' and 'automated packaging', ‘automated picking of lumber/timber.’ While scientific articles on the topic would have been preferred as sources, alternative sources were also used. The authors acknowledge the limitations of these sources, however the use of them is justified for illustrating concepts and start exploring this under-researched field. Case studies and market examples within warehouse automation of construction materials were collected. To develop a better understanding of technological options, solutions from Systraplan, Barbaric and Tentoma were investigated to identify existing technologies that were suitable for handling bulky and heavy materials. The combination of interviews, observations, internal data analysis, and benchmarking provided a triangulation of findings, to achieve validity of the results. 16 Table 3.1: List of interviews and meetings for the master’s thesis project # Title / Description Date Participants Purpose / Key Topics 1 Meeting with logistic responsible - supervisor 2025-01-20 Mathias Hansson Introduction of background, purpose and aim. 2 Meeting with logistic responsible - supervisor 2025-01-24 Mathias Hansson Collecting data, limitations 3 Meeting with logistic responsible - supervisor 2025-01-31 Mathias Hansson Strategic goals, overview of DBI’s operations 4 Meeting with Controller 2025-01-31 Johan Lindblom – Controller Logistics cost structure, KPIs, budgeting, flow metrics 5 Meeting with Transport Planners and Coordinators 2025-02-03 Erik Strand and other internal logistics operators Transport planning, ERP, consolidation, real-time issues 6 Meeting with logistic responsible - supervisor 2025-02-06 Mathias Hansson Technological solutions, logistic operations, DBI’s organisation 7 Meeting with Regional Warehouse Manager – Mölndal 2025-02-06 Daniel Jakobsson Capacity planning, warehouse design, staffing, strategy 8 Meeting with Supply Chain / Procurement 2025-02-11 Daniel Ahrling Inbound flows, supplier deliveries, order handling, procurement strategy 9 Meeting with operation manager at the regional warehouse of Mölndal 2025-02-11 Jens Baitson Packing routines, capacity challenges, planning process 17 # Title / Description Date Participants Purpose / Key Topics 10 Study visit - Central- and regional warehouse of Landskrona 2025-02-13 Mathias Hansson Studies of operations in central warehouse, bottlenecks, future plans 11 Meeting with logistic responsible - supervisor 2025-02-13 Mathias Hansson Bottlenecks in DBI’s logistics, logistical costs, problem statements, sustainable goals, economical perspectives, available resources, storage capacity 12 Meeting with supervisor from Chalmers University of Technology and logistic responsible - supervisor 2025-02-19 Altahir Hassan Irshien Ali, Mathias Hansson Requirements of the new logistics center, research questions 13 Meeting with logistic responsible - supervisor 2025-03-05 Mathias Hansson Assortment analysis and selection 14 Meeting with Regional Warehouse Manager (Derome) 2025-03-12 Roger Sandersson Warehouse operations, staffing, picking/loading processes 15 Interview – Automation Expert 2025-04-07 Per Andersson - automation expert Experiences with automation and its effect on KPIs and logistics 3.4 Data Analysis The data analysis process in this study followed the structured warehouse design framework by Baker & Canessa (2009), focusing on steps 1–6. These include defining system requirements, gathering relevant data, analysing product characteristics, establishing unit loads, and evaluating operating methods and technology. A more detailed illustration of the method used for the data analysis is made in Figure 3.2. The aim was to generate actionable insights for the design of a new logistics centre for DBI, with a focus on automation potential in picking, packing, and loading. The tools used for analysis was: ● Defining System Requirements: The first step was to define system requirements as suggested by Baker & Canessa (2009). Interviews were held to understand the strategic role of the warehouse and were interpreted with strategy literature in mind. Hardy & Brougham 18 (2022) emphasize the importance of detailed process knowledge before implementation of automation. For this reason, process knowledge was gathered and interpreted using the general process flow described in Figure 2.1 (Baker & Canessa, 2022). ● Spreadsheet Analysis (Excel): Baker & Canessa (2009) suggest gathering spreadsheet data on product details, order profiles, SKU demand distribution, etc. It is suggested to use spreadsheet calculation models for analysing the data quantitatively. Excel was the primary tool for quantitative analysis. Historical sales and stock data from DBI were imported into spreadsheets. Pivot tables were used to categorize SKUs by assortment type and frequency class. Calculation models were then applied in Excel. This enabled the identification of high- impact product categories suitable for automation. Figure 3.3 presents an excerpt of the raw excel data. For integrity reasons the complete Excel file is not available and most of the screenshot is blurred. ● Assortment Selection: Baker & Canessa (2009) suggest establishing unit loads using mathematical models. In this study this involves assortment selection. SKUs were classified by order frequency and assortment category, with cutoffs defined through historical data (e.g., fast movers: ≥52 orders/year). By using pivot tables and calculation models it was possible to find the relative sales quantity and number of order lines for each SKU. Category- frequency pairs below 1% of total order lines or sales quantity were excluded to streamline the logistics design. Using the combination of pivot analysis and stakeholder discussions, the number of SKUs in the future logistics centre was reduced while maintaining 99.3% order coverage and significantly reducing complexity. ● Sales quantity calculations: Baker & Canessa (2009) suggest profiling and SKU popularity demand using spreadsheet models and calculating total sales quantity. In this thesis, SKU popularity distribution was analysed by studying historical demand distribution and calculating relative number of order lines for various levels of assortment categorization. Quantitative metrics such as sales quantity and number of order lines were calculated for each SKU class. Adjustments (e.g., 45% reduction of Derome data for specific categories) ensured accuracy in estimating 2024 baseline data. The baseline data was then used to create a forecast for 2029. ● Detailed Category Analysis: By using pivot analysis and spreadsheet calculation models the relative sales quantity and number of order lines could be summarized for different detail levels of assortment categorisation. SKU data and pictures from DBIs website was quantitatively and qualitatively analysed. ● Qualitative Data Interpretation: Baker & Canessa (2009) suggest using both quantitative data and consulting with different stakeholders at the company. Interview notes were coded and cross-referenced with observational data to identify bottlenecks and manual inefficiencies in current operations. For example, specific challenges in picking and loading heavy items were interpreted through both site visits and staff interviews. ● Automation Assessment: As the fourth step, Baker & Canessa (2009) suggest establishing unit loads to be used. As only 5 % of DBIs products are palletised, establishing the unit loads required detailed data analysis as there are almost as many different unit loads as there are SKUs at DBI. Product characteristics at DBI were mapped by studying the spreadsheet data. Individual SKUs were studied in DBIs web shop to determine technical product specifications. Empirical data and literature on automation was studied to analyse impact and 19 technical specifications of automated equipment. An analysis was then made quantitatively and qualitatively to find a match for the DBIs products with automated solutions. This matches the steps five and six of the warehouse design approach by Baker & Canessa (2009), which include determining operating procedures and listing and evaluating equipment types. Automated solutions can commonly only handle a limited part of the assortment (Rathore et al., 2022) which further justifies this analysis. ● Visualisation: Schematic process flows and figures (e.g., current picking flows, layout zones) were used to map operations and identify critical inefficiencies as described by Baker & Canessa (2009). Figure 3.2: Summarization of the analysis process for the issues investigated in the study. Figure 3.3: The figure is a screenshot of the raw spreadsheet data which was used in the quantitative data analysis. 20 3.5 Research Validity & Reliability To ensure reliable results, several types of data were used and compared throughout the study. Interviews, internal spreadsheets, company presentations, and literature were all used to cross-check findings throughout triangulation, as explained in Yin (2017), this has strengthened the conclusions. Assumptions were reviewed by DBI’s logistics management, providing relevant expert input. In cases where data was missing or uncertain, conservative assumptions were made and clearly explained in the documentation. The entire process was carried out with transparency in mind, with clear records of how decisions were made and what sources were used. Since the study was conducted within the context of a single organisation, the generalisability of the findings may be limited. However, the results are considered robust and well-grounded within the scope of DBI’s operations. 21 4 Results & Analysis This chapter presents the empirical findings from interviews and the data collection, as well as the analysis based on the literature related to the case and context. This aligns with the framework of Baker & Canessa (2009) that suggest analysing historical data as well as performing interviews with relevant company stakeholders and summarizing them in useful ways for warehouse design. The aim is to explore how automation can be applied in warehouse design for DBI, and to evaluate which product categories and processes are most suitable for improvement. 4.1 DBI’s current system and strategic goals The first step of warehouse design according to Baker & Canessa (2009), as illustrated in Figure 4.1, is to understand the current system and strategic goals. Hardy & Brougham (2022) suggests that knowledge and mastery of the current process is an enabler of successful automation implementation. Otherwise, the risk is to automate an inefficient process and multiply errors. Chapter 4.1 focuses on documenting the strategic role of the warehouse as well as documenting the current processes as this is crucial for answering the research questions. Figure 4.1: Step 1 of the framework, understanding the current system & strategic goals. Note. Adapted from Baker & Canessa (2009). DBI supplies customers with construction material in the southwest part of Sweden. From an interview with M. Hansson (personal communication, January 20, 2025), it was stated that they have three warehouses, which are in Derome, Landskrona and Mölndal. In 2024, they decided to close the warehouse in Trollhättan, because of its excessive costs relative to income. Now, the warehouse in Mölndal covers the geographical area Trollhättan previously supported. In 2029, DBI plans to build a new logistics centre to cover Derome’s geographical area as well. The logistics centre is planned to be state-of-the-art and suit the context of DBI business by being a node in their new efficient supply chain. The logistics centre is going to function as storage, consolidation area and cross-docking to be able to offer express deliveries (M. Hansson, personal communication, February 6, 2025). Right next to the regional warehouse in Derome (a village with the same name as the company) is where Derome group’s main production facility, its sawmill, is located. In the same location as the regional warehouse and the production facility Derome currently has their central warehouse for wooden planks. The production facility and central warehouse will remain after building the logistics centre. However, part of the flow handled by the regional warehouse in Derome is planned to be covered by the logistics centre. In the warehouse of Mölndal, south of Gothenburg, DBI store a significant part of their construction materials, which are going to be supplied to their customers according to M. Hansson (personal communication, January 20, 2025). Based on a visit to the current warehouse in Mölndal, a blueprint 22 of the warehouse and an interview with D. Jakobsson (Personal Communication, February 6, 2025), the authors developed an understanding of the current warehouse, illustrated in Figure 4.2. The east building contains planed planks, wooden boards, plaster boards, and insulation materials etc. Outside of the east building there is an open area where the trucks can park to be unloaded or loaded. At the west building there is a drive-in area, where customers can drive their own vehicles into a storage and pick up the construction material that they require. At the drive-in there is also a section for wooden mouldings, which the customer can pick. Next to the drive-in there is a store for hardware and tools. Figure 4.2: An overview of DBI’s current logistic center. Since DBI has one storage space for only internal use and another storage space shared with customers, they are using double the amount of space for many SKUs. This is one of the observed issues, stated in the interview with M. Hansson (personal communication, January 20, 2025), at DBI in the current situation. This also causes an issue within the interaction of customers in the storage area. The customer can accidently move articles from one storage shelf to another, which results in errors in the inventory. It can also result in issues for the pickers when an order is received. The inventory indicates that there are units left, and the customer that has ordered is promised to get the item delivered when it is not available. This is because other customers may physically pick the units, creating a mismatch in the inventory data and the real-time inventory. Thereby, the shelf can be empty when the picker arrives. The coordinator at DBI will start to search for the missing SKU at another regional warehouse or at a closely located DBI store, which is very time consuming and could have been avoided if customers were not allowed to pick from the same storage inventory. Next to the east building there is an office area, which is called the control tower and consists of operation manager’s offices, and a space for transport leaders and coordinators. The transport leaders plan the routes for the truck drivers, communicate with sellers to fix last minute changes if possible. The coordinators are planning in what order the pickers should prioritise to match the reloading of Control tower 23 the trucks. The coordinators can also plan consolidation of orders. The pickers receive their orders from a computer and print their picking list (transport coordinators at DBI, personal communication, February 3, 2025). Thereafter they walk to the forklift and follow the picking list to drive to the storage location, which is in the picking list for each row, this route is optimised based on the picker’s own experience J. Baitson (personal communication, February 11, 2025). 4.1.1 Current picking operations Since picking is commonly the most resource intensive process in warehousing it was a focus area in this study. The assortment is highly varied at DBI in weight and size, and therefore the picker is required to adapt their methods depending on the SKU to pick, according to J. Baitson (personal communication, 28 March, 2025). Some SKUs are time-consuming to handle, while others are fast and simple. The picking quantity also affects the efficiency because it directly affects the picking time, productivity, and cost. To further explain the dynamics affecting picking time, a practical example from DBI is provided; planed wooden planks are commonly stored in cantilever racks with four levels. Open packages used for partial picking are typically placed on level one and two, while full, unopened packages are stored on level three and four. In one common figuration, level two holds an open package of one SKU, while level four stores a full package of the same SKU. These full packages measure approximately one meter in both width and height, and the picking process depends on whether a full package or only a limited quantity is required. If the required amount exceeds one full package, the picker can use a forklift to retrieve a complete package from the storage area and move it directly to the loading zone. If the order requires a smaller quantity, the picker will instead move the package to a lower shelf, if no open package is already available, and open it manually. The desired number of planks is then picked by hand and placed on the forklift. After picking, the picker drives to the packaging area, where the wooden planks are manually wrapped using plastic film and secured with straps. The packaged goods are then transported to the consolidation area. All the heavy and/or large sized items, such as wooden boards, gypsum boards and thin steel profiles are made in a comparable way, and the process flow is illustrated in Figure 4.2. Other types of goods are picked manually from pallets, such as cement bags. Most of the cement bags are made of paper and weigh 20 kg each. While they are most often carried by hand from the storage area to the loading zone, they can also be placed on pallets and transported by forklift. Hardware and tools are picked by a separate team located in the store area. This team works with a dedicated picking list and collects items either from in-store shelves or nearby storage. The picked items are then packed and transferred to a designated zone, where the main warehouse pickers retrieve and consolidate them with the rest of the order at the loading area. Reinforcement mesh is particularly time-consuming to handle because of their size and weight. Upon arrival, it is offloaded from the delivery truck and placed in a designated storage area. From there, it is picked and loaded directly onto the outgoing truck for delivery. 24 Figure 4.3: Schematic view of the picking process at DBI. From an interview with DBI’s controller, J. Lindblom (personal communication, January 31, 2025), it was stated that DBI monitors various KPIs, one of them is number of picked order lines per hour. However, this metric can be misleading, because of the high variation in item types. Larger and heavier items are more time consuming to handle compared to smaller ones. This KPI can be compared across different warehouses. For example, in 2024, the number of picked order lines per hour in Mölndal was 34% lower than in Derome. The main reason is that Mölndal typically handles lower order quantities. This becomes even more clear when studying picked volume per worker, which was 17% higher in Mölndal compared to Derome. Additionally, the average quantity per order line is higher in Derome than in Mölndal. These differences highlight the requirement for a more nuanced picking performance measurement at DBI. A classification based on material type would improve the accuracy of performance comparisons and better reflect the nature of the work. For instance, picking single wooden planks or flat steel bars should not be evaluated in the same way as picking small screw packages. To measure this, the RFID-technique would be highly supportive. This is also the case within packaging and loading. 4.1.2 DBIs current assortment Rathore et al. (2022) found that a barrier for implementing automation is that standardised automated solutions cannot handle a varying assortment due to technical constraints. Thus, for being able to implement automation, several automated solutions need to be used, adapted to different parts of the assortment. Baker & Canessa (2009) emphasises analysing the characteristics of products to be handled by the warehouse. For this reason, to further explore the context for answering the research question, DBIs assortment was studied. The planned logistics center will cover the same area as DBIs current regional warehouses in Mölndal, Derome and Trollhättan while Landskrona is outside the geographical scope. The new logistics center will not have the same assortment as the regional warehouses but mostly it will have the same functions as the current regional warehouses. The Mölndal regional warehouse currently has over 7000 SKUs in its assortment. Baker & Canessa (2009) suggests analysing historical spreadsheet data about products, dispatch, order profiles etc as illustrated in Figure 4.3. This is analysed in depth in chapter 4.2, but Table 4.1 25 and Table 4.2 provides an overview. Figure 4.4: Step 2 from the framework; define, obtain and analyse the data. Note. Adapted from Baker & Canessa (2009). DBI has organized each SKU in an assortment category. Every assortment category is further categorised in subcategories. These are further categorised in product categories and finally individual SKUs which is the most detailed level. The analysis follows the framework presented in Figure 4.5. Table 4.1 provides an example overview of DBIs assortment categorization, and Table 4.2 presents examples from DBI’s popular SKUs. Figure 4.5: Obtaining and analysing the data from the assortment. 26 Table 4.1: DBIs assortment categories with respective most sold sub categories. IND (industry products) is excluded because the sales quantity of IND products is negligible. Assortment category Most sold sub categories BM (Building materials) -Sheet materials -Roofing and wall material -Mortar -Rebar and steel -Insulation JV (Hardware and tools) -Screws -Chemicals -Cleaning products SN (Carpentry materials) -Kitchen interior -Tree interior -Doors TR (Wooden planks) -Planed spruce planks -Planed pine planks -Wooden goods Table 4.2: The table shows examples of DBIs categorization of popular SKUs Category/Sub category Product group Figure BM - Sheet material Plasterboards BM - Roofing and wall materials Concrete roof tiles BM - Mortar Dry mortar 27 Category/Sub category Product group Figure BM - Rebar and steel Thin steel profiles BM - Insulation Mineral wool JV - Screws Screws JV - Chemicals Sealant SN - Kitchen interior Kitchen carpentry SN - Wooden interior Wooden moulding 28 Category/Sub category Product group Figure SN - Doors Miscellaneous doors TR - Plane spruce Plane spruce (Construction timber, lath, exterior cladding) 29 4.2 Sales Quantity Continuing with the approach for obtaining and analysing the data in the warehouse design by Baker and Canessa (2009) the next step, shown in Figure 4.5, was to define future sales quantity requirements, by analysing historical sales quantities. 4.2.1 Assortment selection Before calculating the future sales requirements, it was necessary to select the assortment to include in the logistics centre. This step is not defined by Baker & Canessa (2009); however, it was necessary in this case and is illustrated in Figure 4.7 Figure 4.6: Understanding the criteria to select the assortment. If the whole assortment would be included in the logistics centre, the size of the logistics centre would increase, and it would negatively the operational efficiency. Therefore, not all the SKUs will be included in the planned logistic centre. Deciding the number of SKUs to include was conducted by analysing historical sales data from the Mölndal regional warehouse for February 2024 to February 2025. In the analysed spreadsheet each SKU was assigned to a frequency class, fast mover, medium mover, slow mover, and very slow mover according to DBIs definition as defined in Table 4.3. Each SKU was also assigned to an assortment category explained in Chapter 4.1.3. A simplified approach for assortment selection would have been to for cut-off all very slow movers. While this would have been simpler, it fails to manage the complexity of DBIs assortment. For example, JV SKUs can efficiently be transported from DBIs central warehouse to the logistics centre, while other assortment categories are larger and bulkier which justifies including them in the logistics centre assortment. The more detailed analysis in this study ensures an assortment selection which considers DBIs operational dynamics and allow for better performance compared to choosing SKUs purely based on DBIs frequency class. 30 By using a pivot table, it was possible to extract how many SKUs belong to each assortment category and frequency class. The data also included the number of order lines and the total sales quantity for each SKU. Frequency-category pairs were assigned which is presented in Table 4.3. Table 4.3: DBIs frequency classes. Frequency class Order lines per year Very slow movers 0-2 Slow movers 3-11 Medium movers 12-51 Fast movers 52+ When selecting the assortment, each assortment category and frequency class pair was evaluated. The main criteria for selecting the assortment were that if the category-frequency pair was historically included in less than 1 % of order lines or total sold quantity, it was removed from the assortment, as it was negligible. There is also an exception to the assortment selection when choosing the JV (Hardware and tools) assortment. The plan is to supply the JV SKUs from DBIs central warehouse for JV SKUs in Landskrona according to M. Hansson (personal communication, January 31, 2025). Truck deliveries will arrive from Landskrona to the logistics centre every night which indicates that DBI can fulfil their customer promise of delivering the next day without storing the JV articles in the logistics centre. The only purpose of including JV SKUs in the logistics centre is for being able to fulfil express orders, which is defined as delivering the same day as the customer places and order. For this purpose, JV Fast Mover SKUs were included in the assortment. JV medium, slow, and very slow movers were all excluded even if these category-frequency pairs were all above 1 % of total order lines and sold quantity. The reason for this is that DBI can effectively distribute these from their central warehouse which partly eliminates the requirement for including them in the logistics centre assortment. JV SKUs are much smaller in size than other parts of SKU’s assortment, and for this reason a centralised distribution strategy is used by DBI for these products since it is more effective. This is in contrast with the rest of DBIs assortment, which is characterised by large and heavy products with short lead times. A highly centralised approach is ineffective for these product characteristics caused by higher cost per distance for each shipped SKU. A centralised approach can decrease total warehousing cost however also increase the distance the SKUs must be shipped. For smaller SKUs which have a lower cost per distance for each shipped SKU, centralisation leads to lower total cost, while for larger SKUs where shipping prices per unit is higher, a more decentralized approach is preferred. This way of choosing the assortment was decided based on data analysis and discussions with M. Hansson (personal communication, March 5, 2025). The fast mover IND (Industry materials) and fast mover - (unassigned) products are also included in the assortment even though these category- frequency pairs represent very low sales volumes. The reason for including them is that they are expected by customers and required for a complete product offering. This makes these strategically important assortment categories for DBI, and they are thus included. The result of this assortment selection is that the number of SKUs are reduced from 7573 to 2181 while still covering 99.3 % order lines when analysing the historical data from the Mölndal regional warehouse. 31 The included category-frequency pairs and assortment selection is presented in Table 4.4. Table 4.4: The table shows what categories and frequency classes of DBIs existing assortment which will be included in the planned logistics center. X means that it is included and - means that it is excluded. Assortment Category and Frequency Class Fast Mover Medium Mover Slow Mover Very Slow Mover BM (Building materials) X X X - JV (Hardware and tools) X - - - TR (Wooden planks) X X X - SN (Carpentry Materials) X X X - IND (Industry Materials) X - - - - (Unassigned) X - - - The chosen assortment, defined in Table 4.4 as the result from the data analysis of the assortment, together with JV SKUs shipped from the Landskrona central warehouse can cover 99.3 % of DBIs order lines and 99.7 % delivered quantity fulfilling the customer promise of delivering the next day. This number could be even higher assuming SKUs which are not stored in the logistics centre can be delivered the next day through a different method of distribution. Figure 4.7: The result of the assortment analysis. 32 This choice of assortment can also cover 74 % of express orders measured in complete order lines and 96.6 % express orders measured in covered order quantity, as defined in Table 4.5. Express orders are defined as delivering the same day as customers place an order which is only possible if the SKU is included in the logistics centre assortment. This is not a calculation of the expected service level but only how many customer orders are covered by the proposed assortment selection logistics. This is also based only on historical data without forecasting; therefore, the number might also be lower when considering that the customer demand for different SKUs changes over time. Table 4.5: The table shows how the assortment selection in table 4.4 affects how many orders can be covered based on historical data. Parameter Before After (% covered by new assortment + % available through different means of distribution) Number of SKUs 7573 2181 Covered order lines 100 % 99.3 % + 0.7 % Covered order quantity 100 % 99.7 % + 0.3 % Covered express order lines 100 % 74 % + 36 % Covered express order quantity 100 % 99.6 % + 0.4% Customer satisfaction Baseline Maintained Cost-efficiency Baseline Improved Productivity Baseline Improved While the proposed assortment for the planned logistics centre cannot cover all orders compared to the current assortment, it is expected to improve productivity and cost efficiency by reducing complexity through decreasing the number of SKUs. The SKUs which are missing in the planned logistics centre can still be delivered through a different means of distribution, for example through shipping from the central warehouse and being consolidated at the logistics centre, to fulfil the customer promise. It can also be shipped directly from supplier to customer, or from central warehouse to customer. For these reasons, the proposed assortment selection is not expected to maintain customer satisfaction and reduce the logistics cost through prioritizing efficient handling of the high-runner SKUs. The productivity and cost-efficiency for handling the SKUs not included in the assortment might be reduced, however since these only make up a minor part of the throughput, the total productivity and cost efficiency is expected to increase, while reducing cost expected through a more intelligent use of resources. The findings indicate that the same assortment is available in the area covered by DBIs regional warehouses in Derome, Mölndal and Trollhättan. The findings also indicate that the Landskrona regional warehouse has a partly different assortment, however this is not part of DBIs product range for the geographical area the new logistics centre is planned to cover. When the assortment category and frequency class pairs had been established the next step was to calculate how many SKUs are included in these pairs in the geographical area to be covered by the planned logistics centre. This was analysed by studying historical data for the Derome and Mölndal 33 regional warehouses. Trollhättan warehouse was not included in this analysis because it was closed in 2024 which indicates that th