The effect of the drum-buffer-rope (DBR) approach on the performance of a synchronous manufacturing system (SMS)

The main objective of any manufacturing system is to organize the resources in a shop floor for effective transformation of raw materials into finished products. Synchronous manufacturing (SM) is a manufacturing management philosophy that has a set of principles, procedures and techniques where every action is evaluated in terms of a common global goal of the organization (Seetharama et al., 1997, Production Planning and Inventory Control). A manufacturing system that adopts the above principle is called as synchronous manufacturing system (SMS). In order for a manufacturing plant to achieve the benefits of a synchronous operation, a logistical manufacturing (SM) is a manufacturing management philosophy that has a set of principles, procedures and techniques where every action is evaluated in terms of a common global control system that is manageable and results in predictable performance is required. The drum-buffer-rope (DBR) approach, which is a generalized system, satisfies the above requirements through computer simulation. This paper focuses on the effect of DBR principles on the performance of a synchronous manufacturing system. A case study has been taken up in a small-scale industry and analysis has been carried out on the effect of the DBR approach on the performance of the system. This work has been performed on an IBM/PC compatible system using the promodel software and C language.     

The role of Lean at the interface with between operations management and applied services within a large aerospace organisation: a boundary spanning perspective

Increased complexity in large design and manufacturing organisations requires improvements at the operations management (OM)–applied service (AS) interface areas to improve project effectiveness. The aim of this paper is explore the role of Lean in improving the longitudinal efficiency of the OM–AS interface within a large aerospace organisation using Lean principles and boundary spanning theory. The methodology was an exploratory longitudinal case approach including exploratory interviews (n = 21), focus groups (n = 2), facilitated action-research workshops (n = 2) and two trials or experiments using longitudinal data involving both OM and AS personnel working at the interface. The findings draw upon Lean principles and boundary spanning theory to guide and interpret the findings. It was found that misinterpretation, and forced implementation, of OM-based Lean terminology and practice in the OM–AS interface space led to delays and misplaced resources. Rather both OM and AS staff were challenged to develop a cross boundary understanding of Lean-based boundary (knowledge) objects in interpreting OM requests. The longitudinal findings from the experiments showed that the development of Lean Performance measurements and lean Value Stream constructs was more successful when these Lean constructs were treated as boundary (knowledge) objects requiring transformation over time to orchestrate improved effectiveness and in leading to consistent terminology and understanding between the OM–AS boundary spanning team.     

Implementation of Lean Six Sigma framework with environmental considerations in an Indian automotive component manufacturing firm: a case study

Lean Six Sigma is a systematic data driven methodology that integrates two powerful business improvement strategies Lean Manufacturing and Six Sigma with the goal of removing wastes and reducing process variation. Lean Six Sigma has a positive effect on environmental performance as defect reduction and reducing process variation leads to reduction in raw material consumption, energy consumption and reduced scrap which in turn reduces the overall environmental impacts. In this context, this study uses a Lean Six Sigma framework with environmental considerations to reduce overall defects and environmental impacts concurrently to improve the firm’s operational and environmental performance. The framework is based on Define Measure Analyze Improve Control methodology where traditional Lean Six Sigma and environmental impact assessment tools are integrated to systematically deploy LSS strategies with environmental considerations. The framework is validated with an industrial case study conducted in an Indian automotive component manufacturing organisation and the inferences are derived. On successful deployment of the framework, the internal defects was brought down to 6000 ppm from 16,000 ppm and environmental impacts was reduced to 33 Pt from 42 Pt. Deployment of the developed framework helped in improving the firm’s sigma level and also reduced the overall environmental impacts.     

Green and lean: a Gemba–Kaizen model for sustainability enhancement

Abstract

Despite the encouraging results obtained from the application of Green Lean, organizations have found the integration of Green and Lean, and their implementation as an integrated approach, challenging. This paper therefore presents a model for integrating Lean and Green based on the Gemba-Kaizen approach. The proposed model was developed on the basis of a through literature review on Gemba and Kaizen, conducted on peer reviewed journal articles and pragmatic books, and the more than 40 years of accumulated experience of the authors as academics, researchers, industrialists and consultants. The model was validated through two cases study in the aerospace and automotive industries. The results showed that the proposed model helped the case organizations to reduce the consumption of resources and improve their environmental performance. The proposed model can be the basis for further research on Lean and Green, contributing to help organizations to improve their sustainability performance.     

Operationalising lean in healthcare: the impact of professionalism

Abstract

Lean is endorsed as policy in practice in the UK but the challenges and complexities affecting Lean in healthcare are still to be adequately assessed. Through a qualitative single case study of an NHS organisation implementing Lean, 43 interviews with multi-disciplinary team members involved in Lean were conducted. The progress of Lean is found to be inhibited as medical professionals have failed to engage or provide clinical leadership in supporting the trajectory of Lean. This resulted in limited outcomes, sustainability implications, and failed projects. Lean is challenged by complexity and this is evident in conflicts between professional identity, corresponding status and clinical/managerial relationships. Medical professionals as a group have received a limited focus in papers assessing the progress of Lean in Healthcare from an operational perspective. Going forward, strategies for mitigating the negative impact of this can be developed to support operational managers in the healthcare domain.     

Improving patients’ satisfaction in a mobile hospital using Lean Six Sigma – a design-thinking intervention

Abstract

Lean Six Sigma (LSS) that offers a unique integration of Lean and Six Sigma has been accepted globally across services sectors. Previous studies that examined the application of LSS in healthcare were steered in traditional hospital settings. Apparently, there are no studies that highlight the application of LSS in mobile hospitals, an emerging trend in the healthcare sector. The aim of this article is to explore the applicability of LSS in a mobile hospital. The authors present a case study of improving patients’ satisfaction in a mobile hospital, through reducing turnaround time. Design-thinking intervention to LSS helped resolve a real-time problem using Define-Measure-Analyze-Design-Verify roadmap. This article contributes to the ‘healthcare quality” body of knowledge and is novel as it is the first of its kind of LSS application in a mobile hospital underpinning Design thinking. This study is unique as it demonstrates academia–industry collaboration in solving an organizational problem.     

Synergies and misalignments in lean and green practices: a logistics industry perspective

Abstract

This paper conducts an exploratory case study-based research in three companies to identify the main synergies and misalignments between Lean and Green in the context of a range of distribution networks operating globally, regionally and domestically. The research strategy applied by this study is exploratory multiple case studies in three companies, particularly in the road transport and logistics sector. Semi-structured interviews with 15 executives from three companies were conducted to identify activities within logistics operations leading to synergies and misalignment between Lean and Green practices. The outcome of the three cases shows that several improvements can be achieved by the simultaneous adoption of Lean and Green. The study contributes to the literature by extending the research in the logistics sector and providing examples from a wide variety of logistics operations on synergies and misalignments between Lean and Green practices. The findings and outcome of this study are a starting point for further research in the logistics sector.     

Implementation of manufacturing strategy: A select study of Indian process companies

This paper presents findings of an extensive survey of Indian process companies. Based on the survey, three companies have been selected for detailed case studies. Their experiences in the manufacturing strategy process are analysed. Although the companies represented diversity in terms of product type, sales volume, longevity and geographic location, they shared several commonalities including use of advanced manufacturing technologies. The process of strategy formulation varied among the companies in terms of participants, complexity and degree of formalization. Competitive priorities, order winners and critical success factors are identified for these companies. Based on strategic manufacturing issues, manufacturing competence index for the companies has been worked out.     

ALLIANCES BETWEEN COMPETITORS AND CONSUMER INFORMATION

Alliances between competitors in which established firms provide access to proprietary resources—for example, their distribution channels—are important business practices. We analyze a market where an established firm, firm A, produces a product of well‐known quality, and a firm with an unknown brand, firm B, has to choose to produce high or low quality. Firm A observes firm B's quality choice but consumers do not. Hence, firm B is subject to a moral hazard problem which can potentially be solved by firm A. Firm A can accept or reject to form an alliance with firm B, which is observed by consumers. If an alliance is formed, firm A implicitly certifies the rival's product. Consumers infer that firm B is a competitor with high quality, because otherwise why would the established firm accept to form an alliance? The mechanism we discover allows for an economic interpretation of several types of business practices. (JEL: L15, L13, L24, L42, M21, M31, D43)     

Investing in a Shared Supplier in a Competitive Market: Stochastic Capacity Case

When firms invest in a shared supplier, one key concern is whether the invested capacity will be used for a competitor. In practice, this concern is addressed by restricting the use of the capacity. We consider what happens when two competing firms invest in a shared supplier. We consider two scenarios that differ in how capacity is used: exclusive capacity and first‐priority capacity. We model firms' investment and production decisions, and analyze the equilibrium outcomes in terms of the number of investing firms and capacity levels for each scenario; realized capacity is a stochastic function of investment levels. We also identify conditions under which the spillover effect occurs, where one firm taps into the other firm's invested capacity. Although the spillover supposedly intensifies competition, it actually discourages firms' investment. We also characterize the firms' and supplier's preference about the capacity type. While the non‐investing firm always prefers spillovers from the first‐priority capacity, the investing firm does not always want to shut off the other firm's access to its leftover capacity, especially when allowing spillover induces the other firm not to invest. The supplier's preference depends on the trade‐off between over‐investment and flexibility.     

Task parallelism in distributed supply organizations: a case study in the shoe industry

This paper describes the application of the parallel integration evaluation model (PIEM) in an industrial case study. The PIEM model is based on modelling the interactions among supply network parties. It generates the parallel configuration of production and supply servers yielding the minimum total production and supply time/cost for the system, Φ. The design solution recommended by the model obeys the tradeoff that parallelism introduces into the networked supply operating system: while direct-production/supply time Π decreases, the overhead of interaction time among the networked parties, T, increases. The interaction time comprises two delay generating factors, limiting the implementation of massively parallel supply networks: the delay due to communication, negotiation, and coordination among the parties, K, and the congestion delay Γ at shared resources in the supply network. These two types of delay factors are positively correlated with the network's degree of parallelism, Ψ, and they affect inversely the total production supply and delivery time of the organization. The PIEM model has been applied to the case of a globally distributed shoe supply network. The resulting recommendations yielded significant savings of about 35% of the annual operating costs. Following the success of this case study, the model has been generalized and implemented as a supply network design optimization tool.     

A closed loop automatic scheduling system (CLASS)

Abstract

CLASS is a production scheduling system, that is designed to function in either a stand-alone manner, or in conjunction with an MRP system. MRP systems innately do not have 'closed loop’ capability in the sense of being able to produce master schedules and order releases that are consistent and that respect capacity constraints. True closed loop performance requires detailed scheduling. In addition to interfacing with MRP systems, CLASS is designed to produce schedules that can be used in conventional shops or can be downloaded to automated facilities. The design goals for the system, its internal architecture, and its role in manufacturing control systems are described. The modelling and decision capabilities     

Can Environmental Insurance Succeed Where Other Strategies Fail? The Case of Underground Storage Tanks

Private risk reduction will be socially efficient only when firms are liable for all the damage that they cause. We find that environmental insurance can achieve social efficiency even when two traditional policy instruments—ex post fines and risk management mandates with ex ante fines—do not. Inefficiency occurs with ex post fines, when small firms declare bankruptcy and escape their liabilities, limiting the incentives from this policy tool. Firms ignore mandates to implement efficient risk management because regulatory agencies do not have sufficient resources to monitor every firm. The evolution of the U.S. Environmental Protection Agency's and states’ underground storage tank programs suggests that mandating environmental insurance can address inefficiency due to small firms declaring bankruptcy. Comparing insurance mandates to risk management mandates, the burden on a regulator is lower if all it has to do is to confirm that the firm has insurance rather than that the firm has actually, and effectively, implemented required management practices. For underground storage tanks, we show that insurance lowered toxic releases.     

Visualizing and managing value creation through integrated reporting practices: a dynamic resource-based perspective

The article builds on the current debate on how accounting tools can assist top management teams to manage their resources, while communicating a variety of data and information about value creation to their stakeholders. Within this debate, the study focuses on a recent tool for corporate reporting, the Integrated Reporting (〈IR〉), and investigates its utility to support the development of a holistic model for managing strategic resources to create value. To operationalize the 〈IR〉 according to this perspective, the article combines 〈IR〉 with the Dynamic Resource-Based View (DRBV) of the firm on the basis of their common idea that strategic resources are interconnected and have to be managed with the collaboration of all stakeholders in order to inform governance actions and create value with a holistic perspective. For the two case studies analyzed, the information provided by the two organizations’ 〈IR〉 is specifically organized and re-framed using “resource mapping”, which is a DRBV-based visual and analytical technique representing the causal relationships between resources and governance actions. In this way, we not only aim to re-organize and visualize existing information into a new form, but we also expect to describe and communicate the dominant logic in the business and the leverage points where the value creation process lies, supporting the usefulness of Integrated Reporting as a management and governance tool.

     

Utilizing job resources: Qualitative evidence of the roles of job control and social support in problem solving

Abstract

In resource-based models of job design, job resources, such as control and social support, are thought to help workers to solve problems. Few studies have examined this assumption. We analyzed 80 qualitative diary entries (N=29) and interviews (N=37) concerned with the in-role requirements of medical technology designers in the UK for problem solving. Four themes linked to using the resources of job control and social support for problem solving emerged. These were: (1) eliciting social support to solve problems; (2) exercising job control to solve problems; (3) co-dependence between eliciting social support and exercising job control to solve problems; and (4) using job resources to regulate affect. The results were largely supportive of the assumptions underpinning resource-based models of job design. They also indicated that the explanatory power of resource-based models of job design may be enhanced by considering interdependencies between various factors: how different job resources are used, workers' motivation to use resources, workers' knowledge of how to use resources and the use of resources from across organizational boundaries. The study provides qualitative support for the assumption that social support and job control are used to cope with demands.     

The many moods of inter‐organizational imitation: A critical review

The management literature is paying increasing attention to the phenomenon of imitation. However, there are several gaps in understanding what drives firms’ imitative behaviors. Furthermore, a fragmented array of disciplinary perspectives has investigated imitation phenomena in the past. This paper reviews the literature on imitation and offers a unifying framework to understand what theory has said about the predictors of imitative behaviors, in terms of purposes, driving forces and target. At the end of the review, two over‐arching rationales for imitation seem to emerge: risk reduction and search for effectiveness. Next, the review distinguishes between what drives the general propensity for imitation of a firm and what makes a specific decision more likely to be imitated by the same firm. Implications and indications for future research are offered in the final section.

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Defining and assessing industry 4.0 maturity levels – case of the defence sector

Abstract

Firms do not currently fully appreciate the complex characteristics of Industry 4.0 and as a result are uncertain about what it represents for them. In this study, an assessment model is developed to measure the level of implementation of Industry 4.0 technologies, around three dimensions: ‘Factory of the Future’, ‘People and Culture’, and ‘Strategy’. The ‘Factory of the Future’ is the main dimension and is composed of eight attributes: Additive Manufacturing, Cloud, Manufacturing Execution System, Internet of Things and Cyber Physical Systems, Big Data, Sensors, e-Value Chains, and Autonomous Robots. The study uses a defence manufacturing firm to develop, test and validate the model and report on 12 partners. We concluded that the focal firm has an Industry 4.0 maturity level of 59.35, above the sector average of 55.58. This research contributes by empirically developing a model and providing an analysis of major firms in the Defence supply network.     

Lean Six Sigma applied to process performance and improvement model for the development of electric scooter water-cooling green motor assembly

Abstract

In response to the environmental issues triggered by global warming, worldwide companies gradually put the factor of carbon emission into the process of product lifecycle, developing green technology or adopting cleaner production aimed at sustainable development. Lean Six Sigma has advantages of cutting waste and facilitating process improvements as well as system analysis, helping enterprises create the overall business benefits in the value chain. Used in the renewable energy industry, it can promote the triple bottom line (TBL), the performance of sustainable production for corporate profit, social responsibility and environmental responsibility. Therefore, this work took the process performance of the electric scooter water-cooling green motor manufactured in Taiwan with the world’s highest density of scooters as a case study. The developed performance evaluation and improvement model for manufacturing scheduling and process quality achieved the goal of economic benefits of enhancing process quality performance by shortening manufacturing scheduling and reducing process variations with Lean Six Sigma. Besides, they could respond to the policy of energy saving and carbon reduction – replacing the traditional scooters of high-carbon emissions with the electric scooters of low emissions. Furthermore, they could bring enterprises into harmony with economic benefits, ecological benefits and social benefits.     

Measuring impact of Lean implementation on construction safety performance: a structural equation model

Abstract

The construction industry is a risky endeavour. Therefore, it is essential to develop significant safety measures for lowering risks and ensuring safety during projects. However, current safety applications are yet to be developed given the increasing number of workplace accidents. Among these, Lean applications have the potential to improve safety standards and enhance safety performance. Within this context, this study develops components for Lean implementation and construction safety performance, and it presents a conceptual framework to study the relationship between them. A questionnaire was designed and given to Lean practitioners to quantify the impact of the components. Structural Equation Modelling was used to analyse the framework and validate the relationship between Lean implementation and safety performance. The results of the study indicate that there is a significant relationship between Lean implementation and safety performance. The findings also imply that firms that perform well in implementing Lean practices achieve better safety performance. The primary contribution of this research is to prove that Lean practices are closely related to safety performance, with the aim of encouraging construction practitioners to work in a safer environment by using well-established Lean practices. Moreover, the study aims to expand the use of Lean practices to achieve better safety performance by revealing the strong ties between safety and Lean. Finally, this study can guide construction practitioners to adopt Lean techniques and apply them in their projects to enhance safety performance.     

AN EXPOSITION OF MULTIPLE CONSTRAINT SCHEDULING AS IMPLEMENTED IN THE GOAL SYSTEM (FORMERLY DISASTERTM)

Since Eli Goldratt first appeared on the scene in the late 1970s, his ideas concerning production management have generated a huge amount of interest, controversy, and misunderstanding. These ideas have been proliferated under several names such as optimized production technology (OPT), drum-buffer-rope (DBR), synchronized manufacturing (SM), and theory of constraints (TOC). Although there seems to be general agreement on the importance of how capacity-constrained resources are scheduled, research aimed at advancing the state of the art for the specific problem addressed by DBR continues to be limited by prior misunderstandings and the lack of a rigorous examination by the academic community. This paper seeks “to advance the state of research on constraint scheduling in several ways. First, it presents a concise history of the evolution of DBR. It then explains the use of rods in constraint scheduling. Next, it presents in detail the solution algorithm incorporated by the Goldratt Institute in their production software and, finally, relates that algorithm to alternative methods. In the process of these activities, several lingering misconceptions are resolved.