The effect of facility layout changes and 5S implementation on reworks using MCDM: a lean implementation case study

1 Introduction

The implementation of workplace cooperation strategies, along with the 5S methodology, plays a critical role in enhancing Key Performance Indicators (KPIs) and improving organisational efficiency especially in sustaining the growth of SMEs. These concepts when combined with a facility layout strategy are expected to yield exceptional results. Workplace cooperation can be deemed a crucial component in the success of continuous improvement initiatives. Engaging employees in decision-making, goal-setting, and problem-solving increases ownership and accountability of improvement processes and enhances the effectiveness of such efforts. 5S is a Japanese methodology which focuses on organising and optimising workspace environments to improve productivity, safety, and operational consistency (Helmold, 2024). KPIs are strategic tools that enable businesses to measure progress, identify areas for improvement, and make informed decisions. KPI optimisation helps organisations align performance metrics with strategic objectives, ensuring operational improvements can be quantitatively tracked and sustainable over time (Mtau and Rahul, 2024). KPIs are a suitable response to the challenges that are faced by manufactures in the current industrial landscape to enhance productivity, minimise waste and meet targets while upholding sustainability and quality standards.

Chang and Cheng (Chang and Cheng, 2019) support that small and medium-sized enterprises (SMEs) should be actively encouraged to engage in sustainable development. For such initiatives to be effectively identified and implemented, SMEs require both a practical framework and an appropriate management methodology. In this regard, the lean approach adopted in the case study aligns closely with Sustainable Development Goals (SDGs) 4 and 8, as it supports SMEs in enhancing their sustainability, responsibility, and competitiveness, thereby contributing to the advancement of a more sustainable economy. The implementation of lean manufacturing in this context was facilitated through targeted training and the provision of practical guidance. This case study highlights the synergistic effects of workplace cooperation, 5S implementation, and facility layout strategy on KPIs, and the significance of the lean approach in driving both productivity and sustainability, making them especially relevant for the rail transport industry and the manufacturing industry at large.

This study aims to assess how 5S, facility layout and workplace cooperation, as part of a lean approach, impact the achievement of key operational performance indicators. This case study focuses on the implementation of 5S and the use of Multi-Criteria Decision-Making (MCDM) Analytical Hierarchy Process (AHP) in collaboration with the Technique for Order of Preference by Similarity (TOPSIS) to evaluate and rank alternative facility layouts for H4A Pty Ltd, a composite manufacturing company, to enhance productivity and meet critical operational KPIs. The study details the practical implementation process, emphasising how workplace cooperation facilitated these efforts. This study focuses on reducing the amount of production time wasted on reworks.

2 Literature

5S, and Key Performance Indicators (KPIs) are widely recognised as critical components that enhance efficiency, quality, and productivity in manufacturing environments (Midor et al., 2020). However, these cannot be successfully achieved and sustained without effective communication, teamwork, respect, responsibility and accountability. These elements are what has been termed workplace cooperation. This section will explore recent research on the implementation and impact of these elements on organisational performance, employee engagement, and continuous improvement. This literature review synthesises key findings from recent studies to highlight their roles and interactions in fostering operational excellence.

2.1 Workplace cooperation

Workplace cooperation is the collaboration between employee representatives and management to resolve issues of common concern through meetings, consultation, and discussions (Labour Department of Hong Kong, 2025). Workplace cooperation is crucial for the successful implementation of any change or improvement (Chandrayan et al., 2019). It comprises factors such as effective communication, teamwork, respect, accountability, responsibility, effective conflict management systems in an organisation, while also encouraging collaboration between management and staff (Imran et al., 2016).

Workplace Collaboration refers to the process of teamwork in the workplace to achieve a goal or complete a project. Collaboration can occur at different levels, for example, between teams or departments that share ideas, knowledge, resources, and capabilities (Luh and giatno, 2023) or through the different hierarchy levels of the organisation. The collaboration can take many forms, such as team meetings, shared work, or even electronic communication through tools such as email and online collaboration platforms. Effective collaboration can yield positive results, for example, creativity, productivity and overall work environment (Luh and giatno, 2023).

2.2 5S

The 5S methodology, which comprises of Sort, Set in Order, Shine, Standardise, and Sustain, is a basic Lean tool used to develop organised, efficient, and secure work environments (Akram et al., 2023). Recent studies underscore the importance of 5S in maintaining productivity and minimising waste in manufacturing settings. (Alcoba and Alcoba, 2023). Investigate the critical success factors of 5S in Thai manufacturing companies and emphasise that its effectiveness largely depends on employee engagement and management commitment. Moreover, in a study on Lean practices (Gupta, 2022), found that 5S enhances workspace organisation, which directly correlates with higher productivity and product quality.

Another important aspect of 5S is its role in fostering a continuous improvement culture. 5S is a significant tool used to identify opportunities for improvement (Rizkya et al., 2021; Makwana and Patange, 2022). Applied 5S at a plastic machinery manufacturing firm in India. The authors testified that by exposing visible and critical waste in the process, the implementation of 5S can help organisations establish ways to foster sustainable continuous improvement. The study also reveals that 5S has a positive effect on the morale of employees and overall work culture.

2.3 Facility layout

A crucial factor affecting manufacturing productivity is the optimal placement of facilities on the shop floor, referred to as the facility layout problem (FLP). An effective layout reduces material handling costs (MHC), work-in-process (WIP), and overall production time (Pourvaziri and Pierreval, 2017), leading to a decrease in total manufacturing operational costs by at least 10%–30% (Tompkins et al., 2010). In today’s competitive landscape, the ability to swiftly and effectively respond to shifts in product demand is essential for the success of any manufacturing system. As product demand fluctuates, new material flow patterns emerge, causing the existing layout to become less efficient (Pourvaziri, 2022).

Typically, a dynamic or robust layout is utilised to handle fluctuations in product demand. The dynamic approach breaks the planning horizon into several periods, which can range from weeks to months or even years. Each period features its own forecast for material flow, with the assumption that these patterns will remain steady throughout that time. As the material flow shifts from one period to another, the existing layout becomes increasingly inefficient, leading to higher material handling costs (MHC). Consequently, layout changes are necessary, incurring costs related to machine rearrangement. The dilemma arises in balancing the increased MHC with the costs associated with layout modifications. If rearrangements occur on the shop floor, the reduction in MHC is countered by the costs of these rearrangements. These costs can be classified into fixed and variable components. This situation is referred to as a dynamic facility layout problem (DFLP) (Rosenblatt, 1986). The goal of DFLP is to create a layout for each time period in the planning horizon aimed at minimising the total MHC and rearrangement costs (Rosenblatt, 1986).

When using robust FLP, a single layout is used instead for all the periods. A robust layout refers to one that, while not necessarily optimal for any specific time period, performs consistently well across the entire planning horizon by maintaining a balanced design (Kouvelis et al., 1992). Its main goal is to reduce total material handling costs (MHC) over time, thereby ensuring efficiency across a variety of product volumes and configurations, and avoiding the disruptions associated with machine rearrangements (Pourvaziri, 2022).

In industry, the robust approach is generally favoured over dynamic layouts by decision-makers. This preference stems from the tendency of plant managers to tolerate higher MHC costs rather than endure the operational disruptions caused by layout changes—even when such changes might be more cost-effective in the long run (Benjaafar et al., 2002; Lahmar and Benjaafar, 2005). Data show that only about 14% of modern implementations utilise dynamic facility layout planning (DFLP), while the vast majority rely on robust facility layout planning (FLP) (Kulturel-Konak, 2007). Moreover, as noted in (Heragu, 2008), estimates of rearrangement costs often underestimate the full extent of operational difficulties and losses involved (Pourvaziri, 2022).

Flexible manufacturing systems (FMS) provide general adaptability within a defined range of products, helping to accommodate variations in demand (Azab et al., 2013). One key aspect of this flexibility is machine flexibility, which refers to the ability of machines to perform multiple types of operations without significant changeover costs or effort (Wahab et al., 2008). This flexibility can be either partial or complete: fully flexible machines can carry out all required operations, whereas partially flexible ones are limited to specific tasks (Kacem et al., 2002; Vital-Soto et al., 2020; Hsieh, 2018). Regardless of the degree of flexibility, machines capable of performing various tasks allow for alternative routing options, thereby enhancing routing flexibility. This, in turn, helps accommodate shifts in product demand by smoothing material flow and increasing the adaptability of the layout, potentially reducing or even eliminating the need for physical reconfigurations on the shop floor (Pourvaziri, 2022).

The design of a facility’s layout plays a critical role in determining the overall efficiency of a manufacturing system and is widely recognised as a fundamental factor in boosting productivity. Traditionally, facility layout problems (FLPs) have been approached using quantitative measures, such as space utilisation, material handling costs, adjacency preferences, and dimensional ratios, alongside qualitative factors like operational flexibility and product quality. However, with increasing concerns over energy scarcity and rising energy costs, it has become necessary to integrate energy-related considerations into the layout planning process (Yang et al., 2013).

Facility layout aims to minimise cost which are associated with the layout in the production line (Ceylan et al., 2022; Mawson and Hughes, 2019) and optimise the production line (Meller et al., 1998). One of facility layout’s core principles appropriate for this study is to maximise the utilisation of space in industrial facilities (Pérez-Gosende et al., 2021), but fundamental to this study is the elimination of waste, and optimisation of flow.

(Yang and Lu, 2023) gives a concise description of the five facility layout designs commonly used in the manufacturing industry by their characteristics, advantages, and limitations as listed in Table 1.

TABLE 1. A brief analysis of the five common FLDs. Source: Adapted from (Yang and Lu, 2023).

The process layout, also known as a functional layout, groups similar operations together. This layout is suitable for low-volume, high-variety production systems where flexibility is prioritised (Tompkins et al., 2010). For H4A Pty Ltd, this layout could support diverse product lines or bespoke services. However, its tendency to generate long material handling paths and increased in-process inventory presents logistical challenges. In contrast, the product layout arranges workstations in line with the sequence of production tasks and is most efficient for high-volume, low-variety outputs (Topaloğlu, 2024). H4A could benefit from this layout in segments of the operation where mass production is feasible. Its advantages in flow efficiency and line balancing could enhance throughput, although vulnerability to machine breakdowns and rigidity limit its adaptability (Ceylan et al., 2022; Mawson and Hughes, 2019).

The cellular layout, developed from Group Technology principles, seeks to combine the flexibility of process layouts with the efficiency of product layouts by organising machines into cells based on similar processing requirements (Abdul-Hamid et al., 1999). For H4A Pty Ltd, this could streamline mid-volume, semi-standardised production lines. Cellular layouts can reduce material handling and setup time but entail higher initial investment and are less suited for highly customised work (Yang and Lu, 2023). The fixed-position layout is used when the product is too large or heavy to be moved, such as in shipbuilding or construction (Nenzhelele et al., 2023). While H4A may only occasionally require such a setup, particularly for large-scale or bespoke installations, the high space demand and congestion risks must be managed. Finally, the combination layout integrates elements of the other layouts to leverage their advantages and mitigate individual limitations (Kumar and Suresh, 2006). As H4A Pty Ltd considers a more agile operational model, a combination layout may offer the best compromise between customisation and efficiency. However, its design complexity necessitates robust planning and control.

The choice of layout types is generally determined by various performance criteria. The criteria should align with the objectives of the company, thus there is no standard criteria. Flow Efficiency stands as a crucial factor in determining the performance of layouts in various industrial and operational settings. It is significantly impacted by the thoughtful spatial arrangement of workstations and pathways in a facility. Well-designed layouts, such as product-based and cellular configurations, are particularly effective in minimising material handling requirements. These designs not only reduce unnecessary movement but also enhance the continuity of workflow, allowing tasks to flow seamlessly from one stage to the next. By strategically positioning workstations to align with the production process, organisations can improve efficiency, reduce lead times, and ultimately boost overall productivity. Ensuring that pathways are optimised for accessibility and minimised congestion further streamlines operations, fostering an environment where resources are utilised effectively and bottlenecks are less likely to occur.

Space utilisation refers to the strategic organisation and efficiency of physical spaces within a given environment. This concept is crucial in various contexts, such as manufacturing, retail, and office design, as it directly impacts functionality and productivity. For example, product layouts are characterised by their compact nature, designed to minimise storage needs and streamline workflow. These layouts facilitate efficient movement of materials and personnel, reducing the time and space required for operations. In contrast, fixed-position layouts, where products remain stationary and resources are brought to the product, typically demand a larger footprint. This arrangement is often necessary for heavy equipment or large-scale assembly, resulting in more expansive floor space requirements. Understanding the distinctions between these layouts is essential for optimising overall space utilisation, allowing organisations to enhance operational efficiency while also adapting to the specific demands of their activities (Tompkins et al., 2010).

Flexibility, defined as the ease with which a layout accommodates changes in product design or volume, is most associated with process and cellular layouts. Flexibility is increasingly crucial in dynamic markets and is considered a strategic capability in manufacturing.

The production rate, often referred to as throughput, is significantly influenced by how well the layout of a production facility aligns with the flow of production processes. In environments characterised by high production rates, product layouts are particularly advantageous. This is primarily because they facilitate quicker setup times and allow for the seamless execution of sequential tasks. By organising equipment and workstations in a linear fashion that corresponds directly to the manufacturing sequence, product layouts help minimise the time and motion required for transitions between tasks. Consequently, this streamlined approach can lead to improved efficiency, reduced lead times, and ultimately, higher output levels, making it ideal for mass production scenarios where consistency and speed are crucial.

Worker Safety and Ergonomics are impacted by layout features such as spacing, noise control, and accessibility. Poorly designed layouts can lead to accidents, fatigue, or ergonomic injuries, underscoring the need for incorporating human factors in layout planning.

Cost considerations encompass both the capital expenditure of implementing a layout and the operational costs over its lifecycle. Cellular layouts, although sometimes requiring higher initial investment, often result in lower long-term costs due to reduced handling and inventory levels.

2.4 Multi-criteria decision making

Decision-making (DM) can be regarded as a fundamental component of human activity, spreading through virtually all aspects of life. The process typically entails the systematic evaluation of alternative courses of action, informed by the decision-maker’s preferences, prior experience, and the availability of relevant information (Ayan et al., 2023). It is a structured approach used to evaluate and prioritize alternatives when decision involve multiple, and sometimes conflicting criteria. MCDM is popular in manufacturing and operations management for providing a robust framework for systematically comparing options such as facility layouts, process improvements, or technology adoption, while considering both qualitative and quantitative factors (Zhang et al., 2023).

Multicriteria decision making in the context of facility layout evaluation, enables decision-makers to integrate various operational, financial, and human-centered performance indicators into a coherent ranking of alternatives. Criteria such as flow efficiency, space utilization, flexibility, production rate, worker safety, and cost can be assigned relative importance weights, allowing the organization to balance strategic objectives against practical constraints (Chakroun et al., 2022; Ó Longaigh et al., 2023).

A number of MCDM techniques have been widely applied in industrial settings, including the Analytic Hierarchy Process (AHP) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). These methods translate subjective assessments into quantitative scores, thus facilitating objective comparison and ranking thereby supporting decision-making. For instance, AHP uses pairwise comparisons to derive weights for each criterion (priority vectors), which are then applied to evaluate each alternative, producing a final global priority score (Sabr et al., 2023).

The application of MCDM in facility layout decisions is particularly valuable in composite manufacturing environments, where large, complex components and mixed production volumes require balancing efficiency, flexibility, safety, and cost. By structuring the decision process, MCDM reduces subjectivity, ensures alignment with strategic objectives, and improves transparency in trade-off analysis between conflicting criteria (Zhang et al., 2023).

2.5 KPI

Key Performance Indicators (KPIs) are measurable values used to assess and monitor how well an organisation is performing. They are essential tools for tracking progress in areas like continuous improvement, operational efficiency, customer satisfaction, and other key dimensions. According to (Chang and Cheng, 2019; Padovan, 2023), KPIs are instrumental in driving business success by aligning day-to-day activities with broader strategic goals. Additionally (Gomaa, 2025), underscores the role of KPIs in improving decision-making and streamlining operational processes, particularly in service and delivery functions.

(Larsson and Ratnayake, 2021) propose a framework that integrates KPIs with 5S + S (Safety being the sixth element), which includes online audits and dashboards to enhance real-time performance tracking and continuous improvement in engineering projects. This study showcases how KPI-driven meetings foster process-oriented discussions that contribute to better resource allocation, timely decision-making, and alignment with strategic goals.

KPIs have increasingly been seen not just as static metrics, but as live, actionable tools that feed into dashboards, feedback loops, and continuous‐improvement processes. For example, in a recent study by (Carrim and Gupta, 2024), the combination of lean manufacturing with DMAIC methodology led to a 36% increase in Overall Equipment Effectiveness (OEE), achieved through improvements in performance and quality. The study showed how baseline KPIs (availability, performance, quality) allowed identification of bottlenecks, enabling the implementation of specific countermeasures, such as using poka-yoke on a troublesome process segment, which then produced measurable impact in throughput, yield, and waste reduction.

Another example comes from studies in construction and engineering where KPIs have been integrated with Lean Six Sigma and digital technologies + sensors/IoT. In those settings, real‐time monitoring of KPIs (like job lead time, rework rates, delays) enabled project teams to dynamically reallocate resources, reduce delays, and better manage dependencies. One study (Mophethe and Ayomoh, 2024) demonstrated that introducing sensors for real‐time data collection in construction workflows yielded significant improvements in workflow efficiency. KPIs provided visibility into delays and rework causes, thereby enabling corrective actions before delays compounded.

3 Methods

The methods employed in this case study include the 5S implementation process to eliminate waste and the MCDM to evaluate and rank alternative facility layouts, while also applying. The company requires an efficient layout that meets operational needs, optimises production, reduces costs, and enhances flexibility. The methodology consists of identifying relevant criteria, selecting appropriate MCDM tools, and evaluating five common facility layouts: Process Layout, Product Layout, Cellular Layout, Fixed-Position Layout, and Hybrid Layout.

3.1 Case study

H4A Pty Ltd was established in 2018 when two organizations partnered together to help bring world class composite manufacturing capabilities to South Africa. H4A Pty Ltd is responsible for producing high quality composite components and Fiber-Reinforced Plastic (FRP) products which cater to the diverse needs of the rail transport sector using state of the art equipment and processes namely Resin Transfer Molding (RTM), Hand Lamination and Sheet Molding Compound (SMC). Moreover, H4A Pty Ltd is responsible for supplying their client with 427 FRP products that make up 1 Trainset (1TS) on a weekly basis from the 3 special processes.

H4A Pty Ltd experiences challenges with their products internally which would fail their quality check and result in reworks. These reworks cost the company production time. They also noticed that the different departments worked in silos and within those silos, the communication and collaboration among the team members was not very strong despite interventions such as open meetings and discussion which they had attempted several times. Another issue that this organisation faced was the arrangement of the production floor which affected the overall production of the H4A Pty Ltd. The organisation experienced inefficiencies in its production process due to poor facility layout, resulting in excessive transport time, bottlenecks, underutilised space, and high operational costs. The company desires to redesign its facility layout to improve flow efficiency, space utilisation, flexibility and production rate, while ensuring worker safety and cost-effectiveness. Although the firm dies not look disorganised, the tools are not kept in their designated areas and there are no labels to identify what should be kept where, which made 5S a necessary fit for this company.

H4A Pty Ltd management deployed 5 of their staff (Change Champions) to partake in a program which was centered on workplace cooperation and lean manufacturing training to discern techniques that will aid the company achieve optimal productivity by means of fulfilling the “bottom-up’’ approach. Juxtaposed with this, the Change Champions established and adopted an Enterprise Improvement Team (EIT) which comprises of the manufacturing plant operators, Exco members, production supervisors, product leaders and SHEQ members who met weekly. The EIT action plan was initiated to ensure betterment in the following areas: productivity, effective communication, teamwork, reduction in demoralised workforce and induction of a Continuous Improvement culture in the organisation.

The skills acquired from the program empowered the members to formulate an Enterprise Improvement team, implement 5S at the model area, Facility layout, Teambuilding exercises and workplace cooperation.

3.2 5S implementation

The 5S methodology was implemented to improve workplace organisation and efficiency, a conceptual implementation of this methodology was developed and applied within the production unit. As illustrated in Figure 1, it encourages a structured approach to workplace improvement by focusing on five key principles: Sort, Set in order, Shine, Standardise, and Sustain. These principles form a conceptual framework of a systematic approach that helps maintain order and cleanliness in the workplace, thereby enhancing productivity and safety (Akram et al., 2023).

The 5S methodology is anchored on the ideology that when the working environment/factory is clean, orderly and labeled correctly productivity, safety and employee moral improve. Less time is spent looking for equipment, and it eliminates spaces where inefficiency and waste can persist unnoticed.

The 5 stages within the conceptual framework of the 5S methodology, as illustrated in Figure 1 were applied as follows.

3.2.1 Sort (Seri)

Firstly, the members of the production section were required to clear their workstations and rid from them everything that they are currently not using and bring it to a central location to eliminate unnecessary items that were not needed for the current purpose from the workstation. The items were sorted by grouping them into their relevant categories, such as colour, stage within the process for semi-finished products, department, etc.

3.2.2 Set in order (Seiton)

Once the sorting was completed, the items which were sorted together with the workstation itself were then set in order. The purpose of this step is to create efficient and effective storage methods to arrange items such that they are easy to access and use. Labels were utilised in their entirety to ensure that items were easy to find and put away.

3.2.3 Shine (Seiso)

The next step focused on cleaning the factory regularly to ensure that material, tools, equipment and the workspace are kept in good condition. This made it much easier to identify problems such as leaks, wear and tear or any type of malfunction early. It also helped to reduce waste that results from negligence and encouraged accountability. A clean environment enhances safety and improves employee moral.

3.2.4 Standardise (Seiketsu)

The fourth step required that the changes that have been made in steps 1, 2, and 3 be standardised. A 5S checklist was developed to standardise the new changes in order to maintain and monitor the organisation, order and cleanliness daily. A notice board which contained the 5S process and the results obtained from the checklist was set up as a visual management tool to ensure consistency.

3.2.5 Sustain (Shitseku)

Finally, the system to sustain 5S was created. This system entailed auditing 5S according to the checklist regularly, following up on non-conformance, scheduling retraining sessions and putting measures in place to ensure that 5S is not just a methodology but a culture in the department.

3.3 Facility layout

This study uses a multi-criteria decision-making (MCDM) approach to evaluate and rank facility layout alternatives as listed in the table above for H4A Pty Ltd. As one of the main decision-making methodologies, the primary aim of multi-criteria decision-making (MCDM) is to establish the best alternative by considering multiple criteria that are available in the selection process (Taherdoost and Madanchian, 2023). The facility layout problem (FLP) involves determining the optimal geographical placement of production units within a facility, subject to specific design criteria and area constraints, and typically involves one or multiple objectives. As noted in the literature, facility layout design (FLD) constitutes a multi-criteria decision problem because it encompasses both qualitative criteria (e.g., flexibility) and quantitative criteria (e.g., cost considerations) (Shokri et al., 2013). According to (Heragu, 2018), the layout problem in a production system requires determining the most appropriate locations for equipment, workstations, and other departments to achieve the following objectives.

• Minimizing the cost associated with the movement of raw materials, components, tools, work-in-progress, and finished goods between departments;
• Facilitating the smooth and efficient flow of traffic;
• Enhancing employee morale;
• Minimizing the risk of personnel injury and property damage; and
• Ensuring effective supervision and promoting direct, face-to-face communication when necessary (Nenzhelele et al., 2023).

The goal for this study is to identify the most efficient layout by considering multiple performance criteria that impact productivity, cost, and operational efficiency.

The methodology follows a structured decision-making process using the Analytical Hierarchy Process (AHP) combined with Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) to systematically compare and rank different facility layout configurations. The AHP method systematically resolves complex problems by structuring criteria, stakeholders, and outcomes into a hierarchical framework. It balances logic and intuition, assigning priorities through weighted analysis to deliver results that align with expectations, while TOPSIS ranks alternatives by measuring their geometric proximity to the ideal solution using Euclidean distance. The best choice is closest to the optimal solution and farthest from the worst (Widianta et al., 2018).

The process used consists of the steps illustrated in Figure 2.

3.3.1 Selection of facility layout alternatives

The five common facility layout alternatives considered in this study which are adopted independently and not sequentially are listed in Table 1 as follows.

• Process Layout: Grouping similar processes together based on function. Common in job shops or low-volume production environments.
• Product Layout: Arranging resources in a sequential flow, typically used for high-volume, standardised production.
• Cellular Layout: Grouping machines and workstations into cells that process similar products or components, improving flow and reducing movement.
• Fixed-Position Layout: Keeping the product stationary and bringing the necessary resources to the product. Suitable for large, heavy, or custom-built products, like train components.
• Hybrid Layout: A combination of the above layouts, tailored to the specific needs of the organisation.

3.3.2 Identification of evaluation criteria

To evaluate the facility layouts effectively, several key criteria were qualitatively chosen based on observation during company visits and their relevance to the company’s operational objectives, Lean principles, and overall performance. They are grounded on literature on facility layout, operations strategy and lean manufacturing. Figure 3 illustrates the Optimal Layout Set-Up Decision Hierarchy which is used to determine the most optimal layout. The criteria include:

Flow Efficiency: The effectiveness of the flow of components, material and information within the facility with minimal delays, congestion or reworks. Minimising transport time, bottlenecks, and non-value adding motion is also vital to achieving lean operations (Chakroun et al., 2022; Ó Longaigh et al., 2023).

Space Utilisation: The degree to which the available space is used efficiently to accommodate machines, inventory, and other resources. Good utilization strikes a balance between accessibility and compactness ultimately reducing wated space (Ó Longaigh et al., 2023).

Flexibility: The ability of the layout to adapt to changes e.g. product design, demand fluctuations, or changes in production volume. Layouts that allow reconfiguration without major interference add strategic value (Kulturel-Konak and Konak, 2023).

Production Rate: The speed at which the facility can produce the desired output, including throughput times and cycle times for each product. A layout that supports a high production rate is critical for meeting target lead times and volumes (Sabr et al., 2023).

Worker Safety and Ergonomics: The ability of the layout to promote a safe working environment, minimise safety risks, and provide ergonomic benefits for workers as well as compliance with safety regulations A layout that reduces worker fatigue and hazards enhances reliability and morale (Chakroun et al., 2022).

Cost: The initial cost of implementing the layout (including installation of machinery, space utilisation), as well as long-term operational costs (maintenance, staffing). Optimizing layouts must consider total lifecycle cost, not just capital expenditure (Ó Longaigh et al., 2023).

3.3.3 Weight determination using AHP

This section determined the weights of the various criteria (which has been determined qualitatively in the previous section). The weights were then used to calculate the consistency index and consistency ratio. Figure 4 shows a flow diagram of the process.

AHP uses a pairwise comparison matrix to determine the relative importance of criteria. The criteria was ranked by an individual A Saaty scale (1–9) is used in Table 2. This table compared the importance of one criteria against the other in order to get a rank between 1 and 9. In the last row, the sum of all the columns is then tallied.

TABLE 2. Pairwise comparison matrix.

Step 2: Normalise the Matrix and Step 3: Compute the Criteria Weight.

Each column sum is calculated, and each value is divided by the respective column sum using the Linear Normalisation (Sum) as shown in Equation 1:

A n o r m i , j = A i , j ∑ i = 1 n A i , j (1)

c w = ∑ i = 1 n A i , j n (2)

To calculate the Consistency, multiply the original Pairwise Matrix with the Criteria Weights obtained as shown in Table 3 using Equation 2.

TABLE 3. Criteria weights.

E.g. 1 x 0,392,003 = 0,392,003.

Step 3: Compute the Consistency Ratio (CR).

Multiply the original pairwise comparison matrix by the priority vector obtained earlier, and then divide each element of the Weighted sum vector (WSV) obtained from Table 4 by the corresponding priority vector element. The WSV obtained in Table 4 is the n divided by the criteria weights in Table 3 to obtain the ratio as shown in Table 5. The ratios obtained in Table 5 are later averaged to calculate λmax, which is then used to compute the Consistency Index (CI) and Consistency Ratio (CR) as indicated in Equation 3.

TABLE 4. Weighted sum value.

TABLE 5. Weighted sum vector.

Step 4: Calculate the Principal Eigenvalue (λ_max) as illustrated in Equation 3 by multiplying the original matrix by the weight sum vector then dividing it by the corresponding weight, and then get the average.

AHP requires a consistency check and thus a consistency index and a consistency are calculated as shown in Equations 4, 5 respectively:

λ ⁡ max = ∑ Consistency Vectorn / n = 6.67956 + 6.80435 + 6.44199 + 6.77380 + 6.27310 + 6.29179 / 6 = 6 , 5441 (3)

Step 5: Calculate the Consistency Index (CI).

C I = λ max − n n − 1 = 6 , 5441 − 6 / 6 − 1 = 0 , 5441 / 5 = 0 , 1088 (4)

Step 6: Calculate the Consistency Ratio (CR).

Using the Random Consistency Index (RI) value for a 6 × 6 matrix, which is 1.2, Equation 5 was to calculate the CR:

C R = C I R I = 0 , 1088 / 1.24 = 0 , 0877 (5)

Since the CR is approximately 0,0877, which is less than the threshold of 0.10, the pairwise comparison matrix is considered consistent.

3.3.4 Ranking facility layouts using TOPSIS normalization technique

Following the determination of the criteria weights in the previous section, this section applies TOPSIS to evaluate and rank the alternative facility layouts. The TOPSIS method is a multi-criteria decision-making approach that identifies the layout alternative closest to the ideal solution and farthest from the negative-ideal solution. The steps followed are illustrated in Figure 5. The criteria weights and weighted sum vector in Table 5 are derived from AHP criteria weight (Table 3) and weighted sum value (Table 4).

Each facility layout alternative was rated on a scale from 1 to 5 for each criterion, where 1 is the least favourable and 5 is the most favourable. The ratings reflect how well each layout meets the given criterion in the context of H4A Pty Ltd as shown in Table 6.

TABLE 6. Decision matrix table.

Step 2: Normalise the Decision Matrix.

Normalisation adjusts the values to a common scale without distorting differences in ranges as shown in Table 7. The following Equation 6 was used:

r i j = x i j ∑ i = 1 m x i j 2 (6)

TABLE 7. Normalised decision matrix table.

Where.

• ➢ rij = normalized value of the i^th layout under the j^th criterion.
• ➢ xij = original score of the i^th layout under the j^th criterion.
• ➢ m = total number of layout alternatives.
• ➢ n = total number of criteria.

Step 3: Determine Criteria Weights and Construct the Weighted Normalised Decision Matrix:

Assuming equal importance for all criteria, each weight wj is:

Wj = 1 / 6 ≈ 0.1667 (7)

vij = wj × rij (8)

Multiply each normalised value by the criteria weight.

Step 4: Determine the Positive Ideal Solution (PIS) and Negative Ideal Solution (NIS) as demonstrated in Equations 9, 10:

PIS (A⁺): Maximum values for benefit criteria and minimum for cost criteria.

Equations 9, 10 are used to choose the positive ideal solution and the negative ideal solution respectivelywhere V is related to the layout criteria, and B is related to the cost criteria extracted from Table 8.

A + = k + 1 , … , k + h = ⁡ max ⁡ b k a b a ∈ V ) , ( ⁡ min ⁡ b k a b b ∈ B (9)

A + = 0.0996 , 0.0908 , 0.1092 , 0.1124 , 0.0874 , 0.0454

TABLE 8. Weighted normalised decision matrix table.

NIS (A^-): Minimum values for benefit criteria and maximum for cost criteria.

A − = k − 1 , … , k − n = ⁡ min ⁡ b f a b a ∈ V ) , ( ⁡ max ⁡ b k a b b ∈ B (10)

A − = 0.0398 , 0.0454 , 0.0438 , 0.0225 , 0.0524 , 0.0908

Step 5: Calculate the Separation Measures.

Compute the distance of each layout from the positive-ideal and negative-ideal solutions for each layout. Table 9 shows the results obtained for both the positive ideal and negative ideal solutions:

TABLE 9. I deal solution table.

Separation from PIS (S⁺):

S + for Process = 0.0598 − 0.0996 2 + 0.908 − 0.0908 2 + 0.0657 − 0.1092 2 + 0.0449 − 0.1124 2 + 0.0699 − 0.0874 2 + 0.0680 − 0.0454 2 = − 0.0398 2 + 0 + − 0.0435 2 + − 0.0675 2 + − 0.0175 2 + 0.0226 2 = 0.001584 + 0 + 0.001892 + 0.004556 + 0.000306 + 0.000511 = 0.008849 = 0.0940

Separation from NIS (S^-):

S − for Process = 0.0598 − 0.0398 2 + 0.0908 − 0.0454 2 + 0.0657 − 0.0438 2 + 0.0449 − 0.0225 2 + 0.0699 − 0.0524 2 + 0.0680 − 0.0908 2 = 0.0200 2 + 0.0454 2 + 0.0219 2 + 0.0224 2 + 0.0175 2 + − 0.0228 2 = 0.000400 + 0.002061 + 0.000479 + 0.000502 + 0.000306 + 0.000519 = 0.004267 = 0.0653

Repeating these calculations for each layout yields.

Step 6: Compute the Relative Closeness to the Ideal Solution.

To calculate the relative closeness coefficient (Ci) of each layout to the ideal solution using the TOPSIS method, the following formula was used as shown in Equation 11:

Ci = S ‐ / S + + S ‐ (11)

Where S⁺ is the separation from the Positive Ideal Solution (PIS) and S⁻​ is the separation from the Negative Ideal Solution (NIS).

Step 7: Rank Facility Layouts.

Using the previously calculated separation measures in Table 9. The relative closeness coefficient values were calculated as follows:

Process Layout:

Ci Process = 0.0653 / 0.0940 + 0.0653 = 0.4099

Based on these Ci values, the layouts were then ranked as follows:

Combination Layout: Ci = 0.8347.

Cellular Layout: Ci = 0.6688.

Product Layout: Ci = 0.6335.

Process Layout: Ci = 0.4099.

Fixed-Position Layout: Ci = 0.2893.

These rankings indicate that the Hybrid Layout is the closest to the ideal solution, followed by the Cellular Layout, Product Layout, Process Layout, and finally, the Fixed-Position Layout based on the relative closeness coefficient results.

4 Findings and discussion of findings in model area

The formation of an Enterprise Improvement Team was one of the key successes of this program. The primary purpose of the team was to drive change from within the organisation by involving members from various spectrums of the organisation representing management and staff. This team, which was chaired by a staff member in operations, facilitated the smooth running of all the other goals that the program aimed to achieve. The EIT was formed in such a way that it brought management representation and staff representation around the same table to discuss issues pertaining to the operations of the business from both the floor and management and gave a platform for parties to share perspectives and decide on a common resolution regarding the matters at hand. The team was able to successfully set out projects for implementation to the interest of achieving the company’s objectives. This initiative successfully improved teamwork and communication between management and staff throughout the company. This was addressed the second objective of this study which was to improve the relationship between employees and management.

Green area meeting in this company were in existence, however a new structure was introduced through the program which limited the time to 10 min. This meeting was primarily set to communicate the day’s production schedule, report on the previous day’s production and where a team is short staffed, communicate the interim production flow in that team. In this meeting feedback was sought from the members of the department on the previous day’s production, especially when production targets were not met. This meeting ensured that there is continuous communication on production targets and team members were also given a platform to voice any ideas on how production could be improved to meet the daily targets. The new structure of the meeting instilled confidence in the teams as it adhered to a standardised structure and this improved the atmosphere and responsiveness of the teams and most importantly the teamwork and communication. Members of the EIT who were also part of these teams also helped to ensure that the supervisors had support in the implementation of the new structure. Any new projects that would affect the day’s schedule were also communicated in these meetings through the EIT members to demonstrate a shared responsibility to the success of the project. This also played an important role in ensuring that the relationship between employees and management was improved.

The EIT decided that they would use the bonding station as the model area for 5S and facility layout implementation because the biggest bottle neck was in this area. A meeting was held with the staff in the model area to inform them about the project that is about to take place in their department. This marked a great milestone where communication was concerned. The staff members felt considered and involved in the new projected and it encouraged participation from them. This meeting was the inception of ‘5S Moments’ an initiative which was taken by the EIT to inform staff across the company about the 5S project one section at a time. This platform gave staff members a platform to engage in order to gain clarity on the purpose and importance of the 5S project and its expected outcomes.

The decision to use the bonding station was driven by the state of the area, this area was a clustered environment characterised by several tools, jigs, raw materials and other chemicals placed randomly and some just laying around on the table. Figure 6 shows the state of the bonding station before the implementation of 5S. The tools and equipment were laying around making it difficult to keep track of available stock. This also compromised the condition of the equipment and tools putting them at risk of damage. The production process was also extended as unnecessary time would be spent in some instances looking for tools around that are required for the process.

Figure 7 shows the state of the bonding station after the implementation of 5S, and the tools were put in order, which made it much easier to work in that environment. This was also demonstrated by the atmosphere in the department, this project improved the discipline of the employees working in the department in terms of taking accountability of their department and ensuring that their workspace remains clean and orderly (Subburaman, 2019).

The standardization and sustaining elements of 5S ensured that 5S is maintained in the department and records are kept in order by using a checklist that made it easier to pickup when there is a setback and address the issue. This is an important step as it will ensure the continuity of this project and creates a formal reporting system for it.

Figure 8 demonstrates the 5S visual management board that was put up on the model area. The purpose of this visual board is to ensure that all members of the area have access to the 5S procedure and the process of sustaining 5S is transparent. This image shows that 5S has been standardised and audits are being conducted. The results show a successful 5S implementation in the model area. 5S implementation is a very effective lean manufacturing tool on its on, however, in this case study, it was used to pave a way for the successful implementation of the first objective which was to enhance productivity using the facility layout approach.

Facility layout was also implemented in the model area to improve productivity and the process flow in order to achieve greater production output and better product quality with reduced amounts of reworks using MCDM AHP and TOPSIS approach in line with the first objective. The combination layout ranked first with the highest Ci of 0.84, which was the closest to the ideal, followed by product layout with a Ci of 0.77 and cellular layout ranking third with a Ci of 0.75. The rearrangement of the floor based to the combination layout was able to achieve the research objective which was to improve the productivity and operational efficiency. This rearrangement was also able to minimise material handling, reduce production time and ensure a smooth workflow (Chakroun et al., 2022) which also contributed to the improved productivity, and significantly reduced the bottleneck that was previously experienced in this area by improving the workflow.

The new layout was also an instrumental tool in uplifting the moral of the employees and played a role in the maintenance of the 5S. The employees in this area were very proud of their new working environment which highly contributed to the workplace cooperation. The quality of their product also improved significantly as the number of reworks were recorded to reduce over the duration of the program implementation.

The data for the bonding station was collected over the period of March and April as illustrated in Figures 9, 10 respectively as a way to measure the progress of this area in line with the third objective of the study. The figures show that the Bonding workstation Quality Check (QC) gate experienced a high number of products that had brackets bonded incorrectly and some with missing brackets. The figures also show that there was a significant improvement based on the data collected in April compared to that in the month of March. However, the data shows that in the month of April there was only one incomplete bracket which was not represented in March.

With the successful implementation of 5S and the combination layout by the EIT and the staff in the bonding area, the KPIs which were measured in Figures 6, 7 were measured again in the ‘new’ environment. Figure 11 shows the KPI results after the combination layout and 5S were completely implemented.

The employment of the combination layout, effective communication in the green area meetings, support from management through the EIT and the 5S strategy have provided a significant improvement in the quality of the product at the model are as demonstrated in Figure 11. The parts recorded to have brackets bonded incorrectly was at 0% in the month of July. This provided further evidence that by prioritising 5S, the labelled part-specific jigs were used appropriately to avoid parts bonded incorrectly and were conforming as per quality (Q) card specification. One bonding operator added: “The new layout and the use of 5S has helped keep their workstation clean without struggle of having to search at great lengths for clamps, jigs and brackets and are able to meet the daily target.’’

With the success of 5S occurring at Bonding station, the EIT decided to roll out a 5S Moment, a program that occurs every Tuesdays and Thursdays between 11 h00–11 h30 a.m. at shop floor level that seeks to conscientise other Workstation operators on the importance of maintaining 5S in their respective workstations to reach company KPI’s and high productivity levels. The KPIs continue to be tracked in H4A Pty Ltd as a form of measuring and monitoring performance.

The EIT took an initiative to approach management for support in organising a Wellness Day program with the aim of prioritising the staff’s health and financial wellbeing. The call to have the Wellness Day implemented was to assist in boosting workforce morale and emphasising the importance of having the workforce feel appreciated. The success of this event was also testament of a good workplace cooperation. It speaks of good teamwork, communication and respect between staff and management. Over and above this, it also shows that H4A Pty Ltd values its staff and it is willing to invest in employee satisfaction.

5 Conclusions

The partnership of Management staff members through the EIT significantly improved the relationship between management and staff also proving that a healthy collaboration of different levels of within the organisation plays a central role in driving the company’s success. This collaboration became a key point of ensuring that the lean manufacturing program was successful through teamwork, effective communication, and support from the different levels of the organisation, successfully meeting the second objective of this study. The EIT went the extra mile to planning projects such as the Wellness Day, which had a remarkable influence on how the employees responded to work. The implementation of 5S and facility layout also improved the general moral of employees as they were involved in the entire process of the planning, implementation and sustenance of these initiatives which instrumental for their cooperation. The implementation of these two projects resulted in improved product quality, consequently reducing the number of reworked products in the model area and ultimately increasing productivity in the model area. This demonstrated that a clean working environment that has the optimal layout is necessary for increased productivity, meeting the first objective of this study. The last objective of the study was to measure the effect of the implementation of 5S and facility layout in the model area’s performance indicators, and this was done by consistently recording and analysing the production data. The results of this objective were able to the demonstrate gradual improvement that took place over time. The three objectives of this study were successfully met through the implementation of 5S and facility layout strategies to enhance productivity and reduce reworks (improving product quality), the formation of the EIT to drive collaboration between management and staff, and lastly to measure the effects of the 5S and facility layout. In conclusion, the aim of this study which was to create a sustainable approach to reduce reworks and improve the overall productivity in H4A Pty Ltd was achieved by ensuring that management and staff see the value workplace cooperation has in successfully implementing continuous improvement projects.

The limitations of this study were that this study was focused on the output of one organization. Further studies can focus on measuring other types of performance graphs, operator feedback, numerical benchmarks among others.

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Footnotes

Edited by: Darina Dupláková, Technical University of Košice, Slovakia

Reviewed by: Jaroslaw Mark Krzywanski, Jan Długosz University, Poland

Arminda Pata, Instituto Superior D. Dinis, Portugal

Arun Prasath K, Alliance University Alliance School of Business, India