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Environmental sustainability is a main research topic in supply chain management, including sustainable, green, closed-loop, and circular supply chain management concepts. A distinctive feature in concept evolution is the increase in tiers of a supply chain included in the reuse or recycling loop. However, most research focuses on dyadic or triadic supply chain structures. Where to close the loop, i.e., where to position the recycler, repurposer, remanufacturer, refurbisher, repairer, and/or reuser, in multi-tier supply chains remains largely unanswered. In response, this study assesses cost and revenue sharing by analytically modeling monetary flows in linear and circular multi-tier supply chains using linear and circular supply chain models and cost-profit theory to derive equations describing monetary flows between the supply chain tiers and external entities. Results show that firms upstream of the loop-closer are negatively affected by the reuse of material, which leads to an increasingly negative impact on the total profit of the supply chain the further downstream the loop-closer is positioned. This has important theoretical and practical implications since upstream suppliers may leave circular supply chains for linear ones if no offset mechanism is provided. There is no difference between linear and circular supply chains for tiers downstream of the loop-closer level. This effect is normally not considered in the literature, focusing on shorter supply chain structures where all firms are connected to the loop. The most important findings and implications are: If the loop-closer is positioned near the OEM tier or external customer, the total personnel, assets costs and total profits decrease in the circular supply chain compared to the linear supply chain. If the loop-closer is positioned at the most upstream tier level, the total personnel and assets costs, and total profits increase.

Many firms use short-term capacity adjustments to deal with demand changes over time, and a broad literature assesses when and where to adjust capacity. This study highlights that this may be dependent on the type of capacity flexibility used to actually realize the adjustment. By comparing for the first-time capacity adjustments by speeding up processing rates, working in parallel, or using overtime, significant differences in the operational performance are identified, with the latter resulting in the best percentage tardy performance. This provides important insights for the interpretation of the existing literature, guides the future literature, and helps managers to make better decisions.

ABSTRACTThroughput is an important parameter to evaluate production system performance. It is typically constrained by one or more resources referred to as ‘throughput bottlenecks’. To start improvement actions, the first step is to identify throughput bottlenecks. Consequently, several bottleneck detection methods were developed in the literature. But this literature remains largely unstructured, which makes it difficult for practitioners to select an appropriate method. To generate clarity and to consolidate the field, a systematic literature review was conducted. The review identified 14 different bottleneck detection methods that are classified according to the information used: queue states, process states, or combined queue and process states. It further identified three different modes used to operationalize the different bottleneck detection methods: gemba walk, discrete event simulation, and data science. This study further presents important research issues, identifies contingency factors for method application, and discusses important guidelines for the choice of operationalization mode in practice.

Abstract Meeting customer time requirements poses a major challenge in the context of high‐variety make‐to‐order companies. Companies need to reduce the lead time and process urgent jobs in time, while realising high delivery reliability. The key decision stages within Workload Control (WLC) are order release and shop floor dispatching. To the best of our knowledge, recent research has mainly focused on order release stage and inadvertently ignored shop floor dispatching stage. Meanwhile, urgency of job is not only related to its due date, but also affected by the dynamics of shop floor. Specifically, urgency of jobs may decrease at downstream operations in the job's routing, since priority dispatching for urgent jobs accelerates production speed at the upstream operations. And occupying production resources increases the waiting time of non‐urgent jobs at workstation. This phenomenon leads to the change of urgency of jobs. Misjudgement of urgent jobs therefore may result in actual urgent jobs not being processed in time. In response, the authors focus on shop floor dispatching stage and consider the transient status of urgent operations in the context of WLC. The urgency of jobs is rejudged at the input buffer of each workstation, which is firstly defined as urgent operations and non‐urgent operations. Using simulation, the results show that considering the transient status of urgent operations contributes to speeding up production for actual urgent jobs and meeting delivery performance both in General Flow Shop and Pure Job Shop. In addition, percentage tardy performance is greatly affected by norm levels, especially at the severe urgent level. These have important implications on how urgent operations should be designed and how norm level should be set at shop floor dispatching stage.

A production system constrained by workers and machines, where machines are not fully staffed and workers can be transferred between machines, is here considered. Previous simulation research on this type of dual resource constrained production systems assumes that machines are fully reliable. However, this is questionable in most practical situations. Discrete event simulation is used as research method to assess the impact of machine failures on where to transfer workers. Experimentation was carried out for different levels of machine availability, worker utilization and worker assignment rules. Results show that the modified operation due date rule for worker assignment improves tardiness related performance for all production situations considered. This rule shifts between a focus on completing jobs on time and a focus on speeding up jobs with short processing time. Results further show that ignoring the machine state at worker assignment may lead to significant performance deterioration. For a machine availability of 97% and a worker utilization of 90%, a deterioration between 101% and 416% on the percentage of tardy jobs was observed, compared to scenarios where machines are always available. However, if the machine state is considered, deterioration ranges only between 11% and 30% under the same conditions. This highlights the need to considered machine availability at worker assigment.

Book review: “Introduction to Manufacturing: An Industrial Engineering and Management Perspective” by Michel Baudin and Torbjorn Netland (2023) Routledge. ISBN 9780815363194

Background: By examining the recent advancements in technology, particularly the transformation of material into digital flows and its impact on customer demands, the aim of this paper is to investigate supply chain management (SCM) by analyzing seven key constructs: uncertainty, perspective, topicality, coordination, flow, job to be done, and connection. These constructs were chosen since they reflect evolving SCM practices that motivate this study. Methods: We conducted a broad, structured narrative review to comprehensively address the extensive SCM literature. This approach allowed us to evaluate the current state of SCM research and offer recommendations for overcoming prevailing challenges. Results: Our findings reveal the significant impact of technological advancements on SCM operations, requiring companies to adapt and remain competitive. We envision future supply chains as dynamic networks of networks, necessitating the adoption of a value architecture concept that extends a firm’s business model to an ecosystem business model. Conclusions: Considering these changes, our study recommends exploiting uncertainty, adopting demand-driven systems, offering on-demand customized services and products, utilizing prescriptive analytics, prioritizing information flows and services, and embracing open systems with high interoperability. Summarizing these opportunities and challenges that arise with changes in SCM provides interesting venues for future research and valuable insights for practitioners.

When order release is applied, jobs are withheld in a backlog from where they are released to meet certain performance targets. The decision that selects jobs for release is typically preceded by a sequencing decision. It was traditionally assumed that backlog sequencing is only responsible for releasing jobs on time, whereas more recent literature has argued that it can also support load balancing. Although the new load-based rules outperform time-based rules, they can be criticized for requiring workload information from the shop floor and for delaying large jobs. While some jobs will inevitably be delayed during periods of high load, we argue that this delaying decision should be under control of management. A simulation study of a wafer fab environment shows that a time-based rule matches the performance of more complex load-based backlog sequencing rules that have recently emerged. The new rule realizes the lowest percentage of tardy jobs if the lower bound that distinguishes between early and urgent jobs is set appropriately. It provides a simpler means of improving release performance, allowing managers to delay jobs that have adjustable due dates.

Small and medium sized manufacturing companies are important both to economic growth and to supply chains. Yet only limited research has focused on this type of organization – this includes in the area of manufacturing strategy. Using a large scale survey of 149 firms across three States in Brazil, this paper examines the competitive capabilities of small and medium sized manufacturing companies; and the link between their capabilities and performance. Our results show that the best-performing firms are those that lead on capabilities like quality and innovativeness rather than on cost. Much of the available literature on manufacturing strategy emphasizes only four key competitive priorities: cost, flexibility, quality and delivery. Consequently, our results confirm innovativeness as an important, fifth capability for small and medium sized firms in Brazil to maintain or develop. The findings are of relevance both to small and medium sized manufacturing companies in emerging economies and to international firms looking to relocate or outsource to Brazil.

Abstract The improvement in the performance of delivery reliability in Make-To-Order (MTO) companies is an important competitive criterion in the current market environment. This research investigates how a diagnostic framework can be used to identify how delivery reliability is influenced by Production Planning and Control (PPC) decisions. For the development of this research, a case study was carried out in two workshops of a company of the aeronautical maintenance sector. In the workshops studied, delivery reliability performance is influenced by the erroneous determination of due dates (focus on DP-Date time Promissing), with the capabilities being overestimated. The main contribution of the application framework presented is an aggregate analysis of the behavior of the lateness in a certain period of time. Future research should develop criteria for subset creation and further study the framework in order to improve it.