Application of interpretive structural modelling for analysis of factors influencing lean remanufacturing practices

The contemporary manufacturing scenario witnesses the adoption of lean remanufacturing concepts in a concerted manner. Lean remanufacturing is a newly evolved manufacturing process concerned with manufacturing and remanufacturing of products to effectively utilise available energy and resources, while reducing wastes in the process and thereby increasing efficiency. The advantages include process streamlining coupled with end-of-life decisions. A structural model needs to be developed to clarify the interrelationships among factors influencing lean remanufacturing practices. In this study, interpretive structural modelling method has been used to develop the structural model depicting interrelationships and most dominant and least dominant factors. Twenty factors are being identified based on expert opinion from 35 Indian automotive component remanufacturing organisations. The identified most dominant factors include a strong top management commitment with proper strategy selection, long-term vision and participation and a strong understanding of the current product and process designs. MICMAC analysis has been conducted to categorise the factors. The inferences based on the study have been derived. The novel aspect of this study is that it presents the development of structural model to identify the most dominant factors influencing the implementation of lean remanufacturing principles.     

Optimal policies in hybrid manufacturing/remanufacturing systems with random price-sensitive product returns

We study a production planning problem in which a manufacturer aims to meet a random market demand by manufacturing new product and remanufacturing returned product. The product returns are random and price-sensitive. To maximise his profit, the manufacturer needs to optimally decide on the acquisition price for the returned product as well as the quantities of the new product to be manufactured and the returned product to be remanufactured. We investigate two cases based on the relative lengths of the manufacturing and remanufacturing lead times. (1) In the case with a shorter manufacturing lead time, the manufacturer first decides his acquisition price for the returned product before the production starts, and then decides the quantities of manufacturing/remanufacturing after the product returns are realised. (2) In the case with a shorter remanufacturing lead time, the manufacturer first decides the manufacturing quantity and the acquisition price simultaneously, and then the remanufacturing quantity based on the quantity of manufactured and returned products. Each case is formulated as a two-stage stochastic optimisation problem, and the corresponding optimal polices of both are characterised and derived.     

Reverse Logistics: a stochastic EOQ-based inventory control model for mixed manufacturing/remanufacturing systems with return policies

This paper focuses on mixed manufacturing/remanufacturing systems, where manufacturing or purchase of new items integrates product reuse or remanufacturing, with the purpose to achieve a complete and timely demand satisfaction. We formulate a stochastic Economic Order Quantity (EOQ)-based inventory control model for a mixed manufacturing/remanufacturing system. The model is intended to identify the need of placing a manufacturing/purchasing order, to avoid the occurrence of stock-out situations. We then formulate a total cost minimisation problem, to derive the optimal return policy, this latter being a financial incentive paid to customers to increase the flow of returned items. The model developed is investigated through simulations, in order to assess the effect of stochasticity (of demand, return fraction and return delay) on the optimal return policy of the system; then, it is validated through a case study, to derive indications concerning its practical application in real cases. Our study ultimately provides a framework for practitioners to establish EOQ policies in reverse logistics contexts and to evaluate the opportunity of establishing a return policy in those contexts.     

Environmental issue in an integrated production and maintenance control of unreliable manufacturing/remanufacturing systems

This paper addresses a joint production and maintenance problem under environmental constraints and reliability issues in a manufacturing/remanufacturing context. The manufacturing system is composed of one machine producing one type of product. The remanufacturing system, also composed of one machine, retrieves returned products from the market in order to refurbish them. The manufacturing and remanufacturing systems aim to satisfy random demands under a given service level. Moreover, the entire system generates harmful emissions. Exceeding carbon emission limits defined by authorities may risk sanctions. We aim to propose a compromise between ecologic and economic production and maintenance plan by calling on green subcontracting in order to satisfy the demand and avoid emission excess. Three models are proposed in this paper. These models tackle mainly the basic production problems and propose alternative equivalent solution schemas for future extensions. The robustness and usefulness of the proposals are illustrated with various examples and sensitivity analyses.     

Joint decision of product configuration and remanufacturing for product family design

Product family design (PFD) is a popular method for increasing product variety to satisfy the needs of diversified markets. With the increasing concern for environmental friendliness in society, more and more companies develop launching remanufactured products and include them in their product families. Therefore, PFD should be considered in a broad decision space where configuration of product variants and remanufacturing are considered simultaneously. However, this issue was not addressed properly in previous research. In this paper, a methodology for joint decision of product configuration and remanufacturing is proposed in which a bi-objective mixed integer programming model is formulated to determine the configurations of both new and remanufactured products for minimising product cost, maximising total market share, and satisfying reliability requirements. Then, Non-dominated Sorting Genetic Algorithm II (NSGAII) is adopted to solve the optimization problem. Computational experiments were conducted and their results show that NSGAII is convergent to the model well. A case study is presented to illustrate the applicability and effectiveness of the proposed methodology.     

Uncapacitated production planning with multiple product types, returned product remanufacturing, and demand substitution

This paper investigates an uncapacitated multi-product production planning problem with returned product remanufacturing and demand substitution, where no backlog and no disposal are allowed. Both the production of new products and the remanufacturing of returned products are considered to meet time-varying demands in a finite time horizon. Setup costs are taken into account when a new product is manufactured or a returned product is remanufactured. The problem is to determine when and how many returned products are remanufactured and new products are manufactured so as to minimize the total cost, including manufacturing, remanufacturing, holding and substitution costs. We first develop an optimization model to formulate the problem. We then propose a dynamic programming approach to derive the optimal solution in the case with large quantities of returned products. We further propose an approximate approach for the general problem to compute a near-optimal solution. The proposed approaches are evaluated by computational experiments and the effectiveness of the approximate approach is verified. Some managerial insights regarding the effects of remanufacturing/substitution are also obtained from the computational studies. This work was partly supported by the National Science Foundation of China under Grant No. 70329001, 70321001, China Postdoctoral Science Foundation under Grant No. 2003034020, 70501014, SRF for ROCS, SEM (2004) and Hong Kong Research Grants Council under Earmarked Grant No. CUHK 4170/03E. We wish to express our sincere appreciation to the Special Issue Editor and the two referees for their constructive comments and suggestions to help improve our paper.     

Remanufacturing as a means for achieving low-carbon SMEs in Indonesia

Remanufacturing can reduce the energy intensity and associated greenhouse gas (GHG) emissions significantly and increase the eco-efficiency of product systems by utilizing recovered end-of-life parts. This paper presents the GHG mitigation potential of technically feasible remanufactured alternators in Indonesian small- and medium-sized enterprizes. Life cycle assessment approach and Weibull ++8 software have been used to calculate environmental and quality parameters. Since existing remanufactured alternators have not been found to meet the technical criterion for customers’ satisfaction, a number of alternative remanufacturing strategies have been explored to identify an option that has not only reduced GHG emissions but also has satisfied reliability, durability and warranty period criterion. Three improvement scenarios involving three different remanufacturing strategies were investigated in this case study, and yielded useful insights in order to come up with a technically feasible remanufacturing strategy for reducing a significant amount of GHG emissions. The improvement scenario III, which maximizes the use of used components, was found to offer technically and environmentally feasible remanufacturing solutions. Overall, this research has found that about 7207 t of CO₂ -eq GHG emissions and 111.7 TJ embodied energy consumption could potentially be avoided if 10 % of alternators in Indonesian automobile sector are remanufactured using technically feasible remanufacturing strategy.     

A WWW-based integrated product development platform for sheet metal parts intelligent concurrent design and manufacturing

This paper presents a WWW (World Wide Web) based integrated product development platform for intelligent concurrent design and manufacturing of sheet metal parts. In order to achieve this platform, several major modules are discussed. These modules mainly include the structure of the WWW-based integrated product development platform, an information integration framework, a RTCAPP (real time computer aided process planning) module, a customer interface module, and a design/manufacturing knowledge-based module for supporting product design and manufacturing. This paper gives the structure of the information integration framework for concurrent design and manufacturing of sheet metal parts. An information integration framework, called 'step structure information framework' is proposed. The principles, called 'zero thickness and zero bend radius' are put forward, which can be used to abstract the geometric entities of sheet metal parts in order to facilitate product design and modelling. Finally, case studies are given.     

Hybrid manufacturing/remanufacturing lot-sizing and supplier selection with returns,under carbon emission constraint

This paper addresses a lot-sizing problem in manufacturing/remanufacturing systems. The studied system is a single manufacturing line where both regular manufacturing and returns remanufacturing processes are carried out, with different set-up costs for each process. We consider also a returns collection phase from customers/distributors with deterministic returns quantities at each period of the planning horizon. The environmental aspect is assumed in this study by considering a carbon emission constraint for the manufacturing, remanufacturing and transportation activities. A mixed integer programming model to minimise the management cost and meet the customer’s needs under different manufacturing constraints is proposed. Otherwise, An adaptation of the well-known Silver and Meal (SM) heuristic and two hybrid method approaches (HM1 and HM2) providing approximates solutions are developed. The mixed integer model was tested on Cplex (Software optimizer), and the obtained results were compared with the ones provided by the adapted heuristic SM and the hybrid methods. The numerical analyses show that hybrid methods provide good-quality solutions in a moderate computational time. The proposed model establishes a collegial and an integrated process that sets values, goals, decisions and priorities along the considered supply chain while taking into account the environmental aspect.     

A robust optimisation model for hybrid remanufacturing and manufacturing systems under uncertain return quality and market demand

In remanufacturing research, most researchers predominantly emphasised on the recovery of whole product (core) rather than at the component level due to its complexity. In contrast, this paper addresses the challenges to focus on remanufacturing through component recovery, so as to solve production planning problems of hybrid remanufacturing and manufacturing systems. To deal with the uncertainties of quality and quantity of product returns, the processing time of remanufacturing, remanufacturing costs, as well as market demands, a robust optimisation model was developed in this research and a case study was used to evaluate its effectiveness and efficiency. To strengthen this research, a sensitivity analysis of the uncertain parameters and the original equipment manufacturer’s (OEM’s) pricing strategy was also conducted. The research finding shows that the market demand volatility leads to a significant increase in the under fulfilment and a reduction in OEM’s profit. On the other hand, recovery cost reduction, as endogenous cost saving, encourages the OEM to produce more remanufactured products with the increase in market demand. Furthermore, the OEM may risk profit loss if they raise the price of new products, and inversely, they could gain more if the price of remanufactured products is raised.     

A study of the optimal production strategy for hybrid production systems

Due to increased environmental awareness, the issue of recycling and disassembling damaged or malfunctioning products after consumption to obtain useable parts for remanufacturing has become essential. This study considers a hybrid production system with both external and internal reverse logistics in which the external recycled products are utilised for remanufacturing to satisfy demand first, and then the ordinary manufacturing process may supplement this if there is any shortage in production. In addition, the defective items produced internally by either the manufacturing or the remanufacturing process can also be repaired by a remediation process. The objective of this study is to determine the optimal strategy for the manufacturing, remanufacturing, disposal, and remediation rates. Three conditions are considered in which the production strategy varies with different yield rates and capacity limits. The impacts of related factors on the production strategy are investigated to probe the trade-offs between product consumption and environmental protection.     

Improving the NPD Process by Applying Lean Principles: A Case Study

Abstract:

This article extends the new product development (NPD) literature by presenting a case study of a lean product development (LPD) transformation framework implemented at a U.S. based manufacturing firm. In a departure from typical LPD methods, in this article the design structure matrix and the cause and effect matrix are integrated into the lean transformation framework, allowing analysis of the underlying complexity of a product development (PD) system, and thus facilitating determination of the root causes of wasteful reworks. Several strategies to transform the current PD process into a lean process are discussed. Besides the two-phase improvement plan, a new organizational structure roadmap and a human resources plan are also suggested to support the recommended changes in the NPD process. The results of the first phase show a 32% reduction in PD cycle time due to the proposed NPD process. The article concludes with lessons learned and implications for engineering managers based on the case study.     

A Multilevel Framework for Lean Product Development System Design

Abstract:

Organizations today face intense and growing pressure to reduce cost, decrease time to market, and maximize stakeholder value in product development (PD). Many organizations have adopted lean product development (LPD) methods in an attempt to improve their PD systems; however, despite two decades of research, there is still much less understanding of the characteristics of effective LPD systems than of effective lean manufacturing systems. LPD systems are complex systems involving multiple organizational levels; however, most LPD research to date has focused only on a single level. There is currently a lack of understanding of the interactions between levels and effective means for managing these interactions. In this article, we propose a multilevel framework designed to capture key LPD system principles at the functional, project, and portfolio levels; tools and practices for implementing principles at each level; and approaches for managing the interactions between levels. A longitudinal case study is used to expand and refine a conceptual framework developed through literature review. Future research should focus on further validating the framework and applying the framework to improve LPD system design.     

Green Remanufacturing Engineering and Its Development Strategy in China

Made in China 2025 proposes that “develop the remanufacturing industry vigorously, implement high-end remanufacturing, smart remanufacturing, and in-service remanufacturing, advance the identification of remanufacturing products, and promote sustainable and healthy development of the manufacturing industry”. Remanufacturing is an extension of the manufacturing industry chain, and it is an important part of advanced manufacturing and green manufacturing. The product function, technical performance, greenness and economy of the remanufacturing products are no worse than those of the new products. The cost of remanufacturing products is only about 50% of new products. Remanufacturing can save energy 60%, and material 70%, so the adverse impact on the environment is significantly reduced. At present, China’s remanufacturing industry is developing rapidly, and the manufacturing pilot has been in full swing. Meanwhile, the policies and regulations, basic theory, key technology, and industry standards of remanufacturing have been continuously innovated and completed.     

Quality and reliability information integration for design evaluation of fixture system reliability

Quality and reliability are two important factors in manufacturing‐system design. However, the analysis and optimization of manufacturing‐system reliability and product quality are normally conducted separately in practice. There is no general framework to integrate these two important factors, quantitatively analyze the interactions between them, and further study their integrated effects on the manufacturing‐system performance. In this paper, the QR‐Co‐Effect of product/part quality and manufacturing‐system component reliability is investigated in an assembly fixture system. The concept, model and analysis of QR‐Co‐Effect are addressed in this paper. Copyright © 2001 John Wiley & Sons, Ltd.     

Method for assessing human resources management practices and organisational learning factors in a company under lean manufacturing implementation

The implementation of lean production systems is deemed essential for companies that wish to obtain high levels of competitiveness. There are several examples in the literature discussing the adoption of lean roadmaps; however, since such maps emphasise technical factors of lean change, the organisational learning (OL) process and human resources management (HRM) practices tend to be neglected. This article presents a method for assessing the impact of HRM practices and OL factors in a company under lean implementation. The method incorporates concepts of HRM and OL into lean implementation roadmaps, enabling a maturity analysis regarding dimensions of OL at different contextualisation levels, and allowing the proposition of improvements in HRM practices. The proposed method is illustrated in a case study from the automotive parts manufacturing sector.     

A review of designing machine tool for leanness

As an ideology, Leanness is not a new concept but still researchers strive for developing new methods to reduce almost all kinds of identified wastages at almost every stage and in every activity ?? right from design till delivery of final product to the end-customer. Newly developed manufacturing ideologies, paradigms and systems are always critically examined from the point of view of leanness. In other words, leanness is becoming an important evaluation tool to compare the recently developed/pioneered approaches. There has been a gradual evolution of the leanness over the years from the shop floor level of a manufacturing (automobile) organization to almost every operational and management aspect now. The Leanness has undergone and still is undergoing a process of continuous and never-ending evolution due to its inherently built dynamic concept of continuous improvement. Although in the literature a lot of work has been reported to the application of lean tools, principles, theories and methodologies to production systems, but a very few is evident in the area of Lean design process of a product and machine tool. For this reason an attempt is being made here to focus a significant proportion of this paper on evolutionary aspect of leanness from manufacturing to design stage. Also, this paper reviews the concepts and practices being followed till date by the industrialists, researchers and academicians in applying lean tools and techniques in the design of product and machine tools along with the methods to measure the lean improvements in the systems.     

A strategic framework for the design and implementation of remanufacturing operations in reverse logistics

Reverse logistics (RL) is a systematic process that manages the flow of products/parts from the point of consumption back to the point of manufacturing for possible recycling, remanufacturing, or disposal. Although the concept of RL is well-known in logistics and supply chain management, the available holistic literature and theory of RL are scarce. This paper surveys current RL literature and identifies the present state of theory in RL by formulating the propositions for strategic factors. The approach used is grounded theory development. The strategic factors are in turn delineated and evaluated in terms of specific sub-factors associated with each factor by the use of interview protocol and within the context of an in-depth analysis of two companies in different industries that are engaged in remanufacturing/recycling operations within RL systems. The analysis of these case studies, using the grounded theory approach, resulted in insights regarding their RL practices. Based on these insights and strategic factors and sub-factors, a framework for effective design and implementation of remanufacturing/recycling operations in RL is provided. This framework allows for the determination of the viability of returned products/parts in the RL system. The findings outline how our RL theory is enhanced and how our understanding of RL practices with respect to remanufacturing/recycling operations is improved. In conclusion, managerial implications and future research directions are presented.     

Optimal acquisition policy in remanufacturing under general core quality distributions

The quality of acquirable used products (cores) is highly variable, which has made production planning and control of remanufacturing systems difficult. This paper studies an acquisition problem in presence of uncertain core quality. In order to derive optimal acquisition policy, the problem is formulated as a non-linear integer programming model in the framework of order statistics. The model is a strictly discrete convex problem with a unique global minimal solution. Then, a single bisection method is developed to obtain the optimal solution under a general continuous quality distribution. Moreover, the expressions of the optimal solution in some frequently used quality distributions are derived. Furthermore, the model is extended to the case of a general remanufacturing cost function, and corresponding results are presented. Finally, numerical experiments are conducted to test the effects of quality distribution, cost relationships of acquirable cores and remanufacturing cost function.     

Dynamic disassembly planning for remanufacturing of multiple types of products

With the increased need for remanufacturing of end-of-life products, achieving economic efficiency in remanufacturing is urgently needed. The purpose of this study was to devise a cost-minimisation plan for disassembly and remanufacturing of end-of-life products returned by consumers. A returned end-of-life product is disassembled into remanufacturable parts, which are supposed to be used for new products after being remanufactured. Each end-of-life product is disassembled into parts at variable levels and through variable sequences as needed, taking into account not only disassembly but also manufacturing, remanufacturing, and holding inventory of remanufacturable parts. This study proposes a mixed integer linear programming (MILP) model for derivation of the optimal disassembly plan for each returned product, under deterministically known demand and return flows. For the purposes of an illustrative example, the proposed model was applied to the formulation of an optimal disassembly and remanufacturing plan of ‘fuser assembly’ of laser printers. The solution reveals that variable-level disassembly of products saves a significant remanufacturing cost compared with full disassembly.