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Global greenhouse gas emissions must be reduced to achieve net-zero carbon emissions. One of the solutions for the reduction of greenhouse gas emissions is the adoption and transition from conventional vehicles to electrical vehicles (EVs). Previously, most research on EVs have been from a consumer adoption perspective, few of them are from industry transition and consumer adoption perspectives simultaneously. This also highlights the importance of SDG 12 (responsible for consumption and production). Additionally, the analyses were mostly obtained using one methodology and demonstrated only by weighting without relationships among factors. To consider the problem of adoption and transition, a systematic method should be developed. Therefore, this study intends to identify, prioritize, and display the relationship between EV adoption barriers from an automotive industry perspective using an analytic network process (ANP) and the decision-making trial and evaluation laboratory (DEMATEL) method. The research results show two contributions: First, the identified and prioritized barriers that automakers encounter in EV transition also explored the interrelationships among these barriers. Second, a model comparison of two multicriteria decision-making approaches was conducted to prioritize and identify the interlinkages among EV uptake barriers.

This paper develops an imperfect inspection policy for systems subject to multiple correlated degradation processes. The degradation processes are characterized by a multivariate Wiener process, and the dependency among the processes is described by a covariance matrix. A failure occurs when any of the degradation level exceeds a specific threshold. As degradation-based failures are usually dormant, inspection is required to detect the failures and prevent potential losses. The inspection is imperfect, in such a way that a failure may not be discovered at an inspection. Optimal inspection interval is obtained by minimizing the long run cost rate. In addition, the properties of the optimal inspection interval are studied and the upper and lower bounds of the optimum value are achieved. An example of fatigue crack development is used to illustrate and evaluate the inspection policy. The results imply that inspection accuracy contributes significantly to reducing the operating cost and more efforts should be made to improve the inspection quality.

This paper proposes a variables two-plan sampling system involving normal and tightened inspections, denoted as TNTVSS-, for controlling process fraction nonconforming with a unilateral specification limit based on one-sided capability indices. The system utilises two single variables sampling plans with different sample sizes and the same critical acceptance value , where and are sample sizes required for tightened inspection and normal inspection, respectively. The tightened inspection plan is used when the quality deteriorates and the normal inspection plan is used when the quality is found to be good. The operating characteristic (OC) function of the proposed sampling system is developed based on the exact sampling distribution. The plan parameters under various settings are determined by solving two non-linear equations simultaneously, which satisfy the required quality levels and allowable risks given by the producer and the consumer. The behaviour of the proposed sampling system in terms of the OC ...

This paper investigates the optimal single replacement policy for products with free-repair warranty (FRW) under a finite planning horizon (FPH) from the consumer’s perspective. Within the planning horizon, the product is replaced once by a new product. During FRW, when the product fails, the failed product is rectified using minimal repair without any cost to the consumer. After FRW, any failure of the product incurs a fixed repair cost to the consumer. However, each failure incurs a fixed downtime cost to the consumer over the planning horizon. Under this maintenance scheme, the replacement of the product is investigated for two separate cases: before FRW and after FRW. Then, two cost models from the consumer’s perspective are derived and the optimal replacement policy is obtained such that the expected total disbursement cost is minimized. Finally, numerical examples are given to illustrate the features of the optimal replacement policy under various warranties and planning horizons.

Manufacturing product exhibits several quality characteristics. Quality inspection becomes a crucial way to verify product conformance to requirements. Under certain inspection procedures, we may identify whether the product quality conforms to specifications or not. If the product quality fails to conform, many possible reasons come include problems from the preceding manufacturing process. Performance of the manufacturing equipment is substantial to preserve the production process. The well- maintained equipment ensures the high-quality product. The roles and advantages of quality inspection and equipment maintenance have been individually well-addressed in literatures. The investigations on these two aspects−inspection and maintenance, suggest realizing their relationships as such a way to preserve better quality assurance. However, the link between them has not been sufficiently investigated and modelled. This paper proposes a general framework of interaction between inspection and maintenance, which provide a comprehensive managerial thinking in equipment maintenance. Two approaches are offered to preserve useful initiation of possible joint optimization model for future research

Acceptance sampling plans provide decision rules for lot acceptance determination based on the required quality levels and allowable risks. In this paper, we develop a variables sampling plan based on the one-sided process capability indices, CPU and CPL, when lot resubmissions are permitted on non-acceptance of the original inspection. The plan parameters are determined by solving two non-linear equations simultaneously and fulfill the two-point condition on the operating characteristic (OC) curve. The OC curve of the proposed plan is derived based on the exact sampling distribution rather than approximation. Moreover, the behavior of the proposed resubmitted sampling plan for various parameters is examined and discussed. For practical purposes, the sample size and critical acceptance value are tabulated for various parameter values. An example is used to demonstrate the implementation of the proposed resubmitted sampling plan.

For a multiple component parallel system, the operation of each component is independent, that is, any failure of component will not affect the normal operation of the system. Due to the inevitable deterioration of the component, it may fail more frequently when its age increases. In order to reduce the number of failures, the component should be replaced at a certain age. When a replacement action of the component is performed, it will incur a replacement cost and a setup cost. Under this situation, grouping replacement for all components is an important policy in order to reduce setup cost. This paper derives a formula of the grouping replacement for a n-component parallel system. Further, an optimal grouping replacement method is offered, and the optimal replacement time of each group is obtained.

To make good profits, pricing is a competitive weapon of service firms. This paper is concerned with pricing strategies for services with substantial facility maintenance costs. To address the problem, a mathematical framework that incorporates service demand and facility deterioration is proposed. The facility and customers constitute a service system driven by Poisson arrivals and exponential service times. The most common log-linear customer demand and Weibull-distributed facility lifetime are also adopted. By examining the linkage between customer demand and facility deterioration in profit model, pricing policies of the service are investigated. Then analytical conditions of customer demand and facility lifetime are derived to achieve a unique optimal pricing policy. Finally, numerical examples are presented to illustrate the effects of parameter variations on the optimal pricing policy.

The partnerships of performance-based contracting (PBC) between government and original equipment manufacturer (OEM) have been well demonstrated in most studies, but very few attempts have been made at such partnerships between a foreign government (FG) and a localized third-party logistics (3PL) supplier while they operated the same system. This article constructs a principal-agent model to support resource allocation, and then uses it to analyze commonly observed risk-aversion contracting between a FG customer (principal) and a localized 3PL logistics supplier (agent) with cooperative game combinations by fixed payment, cost-sharing incentive, as well as a performance incentive conditions. Finally, a real military logistics service application in Taiwan is demonstrated by the assessment model to generate the maximum utilities while under cost-sharing incentive condition by using offset obligation between FG and OEM.

This article formulates a novel fuzzy multilevel multiobjective production planning model for a supply chain under a fuzzy environment. An efficient two-phase interactive solution procedure is developed to obtain a good solution that maximizes the total supply chain profit and the satisfactory degree. The proposed solution procedure, modified from Sakawa et al.’s interactive fuzzy programming approach, can be easily adopted by practitioners. Through a negotiation case study, a well-known network product manufacturing supply chain in Taiwan is presented to demonstrate the effectiveness and aptness of the proposed model and the solution procedure, as compared with Sakawa et al.’s method with only one objective at the manufacturer level. Finally, several important findings and managerial implications are drawn from the results of this study.

For survival and success, pricing is an essential issue for service firms. This article deals with the pricing strategies for services with substantial facility maintenance costs. For this purpose, a mathematical framework that incorporates service demand and facility deterioration is proposed to address the problem. The facility and customers constitute a service system driven by Poisson arrivals and exponential service times. A service demand with increasing price elasticity and a facility lifetime with strictly increasing failure rate are also adopted in modelling. By examining the bidirectional relationship between customer demand and facility deterioration in the profit model, the pricing policies of the service are investigated. Then analytical conditions of customer demand and facility lifetime are derived to achieve a unique optimal pricing policy. The comparative statics properties of the optimal policy are also explored. Finally, numerical examples are presented to illustrate the effects of para...

Systems experiencing multiple dependent competing failure processes (MDCFP) have attracted much attention in the recent years. A system subject to MDCFP with damage self-recovery phenomenon is considered in this paper. Due to the intrinsic resistance to abrupt damage, the damage self-recovery exists in many systems and products. A new reliability model subject to MDCFP by considering the damage self-recovery phenomenon is developed. For each random shock, we propose recovery time and recovery level concept to describe the self-recovery process. The model is practical and realistic for many complex systems such as electrical devices or microelectronic polymeric components. Due to complexity of the model, there is no analytical form of the reliability function. However, we estimate the system reliability efficiently by using simulation method.

This paper investigates the optimal length of lease period and maintenance policy for leased equipment. In order to have steady revenue, the lessor (owner) of equipment may provide a discount to encourage the lessee (user) to sign a contract with a longer lease period. However, as the lease period increases, the maintenance cost also increases due to the deterioration or usage of the equipment. Therefore, there is a need to determine an appropriate length of lease period and a corresponding maintenance policy for the leased equipment from the viewpoint of the lessor such that the expected total profit is maximized. In this paper, the following maintenance scheme is considered. When the leased equipment fails, a minimal repair is conducted to bring the equipment back to an operating condition. Furthermore, when the age of the equipment reaches a specified level (called as a control-limit), an imperfect preventive maintenance (PM) is carried out to avoid possible failures. Under this maintenance scheme, the mathematical model of the expected total profit is developed and the optimal length of lease period and the corresponding optimal maintenance policy are derived. Finally, some numerical examples are given to illustrate the effects of the length of lease period and the maintenance policy on the expected total profit.

This paper proposes two maintenance schemes for reused products. In order to reduce the purchasing cost or conform to the concept of environmental protection, reuse is considered as one of the most efficient strategies. However, the initial quality of reused product is often inferior to the new one and then product failures will occur frequently during usage period. Therefore, two periodical preventive maintenance (PM) policies in this paper are developed to decrease the high failure rate of the second-hand products. When a second-hand product with Weibull life time distribution of known age is intended to be used for a pre-specified period of time, the optimal number of PM actions and the corresponding maintenance degree are derived such that the expected total maintenance cost is minimized. The impact of providing preventive maintenance is illustrated through numerical examples.

This paper investigates the effects of preventive-maintenance cost functions on the optimal preventive-maintenance policy for a leased product with Weibull life-time distribution. During the lease period, any product failures are rectified by minimal repairs and may incur a penalty to the lessor, if the time duration for performing a minimal repair exceeds a pre-specified time limit. To reduce repair costs and possible penalty, preventive-maintenance actions are scheduled in the lease contract. The objective of this paper is to derive the optimal preventive-maintenance schedule and maintenance degrees such that the expected total cost is minimized. Some structural properties of the optimal policy are obtained and an efficient algorithm is provided to search for the optimal policy. For the cases where the preventive maintenance cost is a constant or a linearly increasing function, the effects of the preventive-maintenance cost function on the optimal policy are investigated in detail both theoretically and numerically.

Previous studies have proposed an integrated production and inspection model for a deteriorating production system whose process is characterized by an exponential distribution. Since the simultaneous determination of the optimal scheduled inspection times and the optimal production run length is difficult, an approximative production and inspection solution is obtained under the condition that the optimal inspection policy is equally-spaced. That is, obtaining an approximative production run length and number of inspections. This study further investigates this approximative solution and demonstrates that how to utilize it to obtain the real optimal solution more efficiently.

This study proposes a maintenance scheme for leased equipment using failure rate reduction method and derives an optimal preventive maintenance (PM) policy that minimizes expected total cost. Under the proposed maintenance scheme, the lessor (equipment owner) rectifies failures with minimal repairs within the lease period, and the lessor may incur a penalty when repair time exceeds a time limit as specified in the lease contract. To reduce the expected total cost, the lessor may employ PM actions to decrease the number of possible failures. In this study, an efficient algorithm is developed to derive the optimal PM policy and a closed-form solution is obtained for the case where the lifetime distribution of the equipment is Weibull. The expected total cost using the optimal PM policy under the proposed maintenance scheme is then compared with the performance of other policies under various maintenance schemes through numerical examples.

Effective personnel assignment is one of the most crucial tasks performed by the decision makers of a company. This paper proposes a systematic approach with a feedback mechanism in which the interdependences among positions and the differences among the selected employees are considered simultaneously. Unfortunately, the two combined considerations have rarely been discussed in the literature. The purpose of this approach is to obtain the best matching of candidates and positions in order to organize a collaboratively cross-functional team. In a fuzzy environment and, then, in the proposed approach, a bi-objective binary integer programming (BOBIP) model is formulated. Based on the weighted composite scores determined in the third step of the proposed procedure, the BOBIP model is transformed into a fuzzy bi-objective goal programming (FBOGP) model. An elaborately designed heuristic algorithm is developed to determine the appropriate values of several important parameters in the FBOGP model, which is solved using LINDO 8.0. An application example is illustrated, and two additional examples are tested. The results indicate that the proposed approach achieves the acceptable satisfaction level and requires less computation time than the brute force enumerative method.

Vendor selection is an evaluation process that is based on many criteria that uses inaccurate or uncertain data. But while the criteria are often numerous and the relationships between higher-level criteria and lower-level sub-criteria are complex, most conventional decision models cannot help us clarify the interrelationships among the sub-criteria. Our proposed integrated fuzzy multiple criteria decision making (MCDM) method addresses this issue within the context of the vendor selection problem. First, we use triangular fuzzy numbers to express the subjective preferences of evaluators. Second, we use interpretive structural modeling (ISM) to map out the relationships among the sub-criteria. Third, we use the fuzzy analytical hierarchy process (AHP) method to compute the relative weights for each criterion, and we use non-additive fuzzy integral to obtain the fuzzy synthetic performance of each common criterion. Fourth, the best vendor is determined according to the overall aggregating score of each vendor using the fuzzy weights with fuzzy synthetic utilities. Fifth, we use an empirical example to show that our proposed method is preferred to the traditional method, especially when the sub-criteria are interdependent. Finally, our results provide valuable suggestions to vendors on how to improve each sub-criterion so that they can bridge the gap between actual and aspired performance values in the future.

This paper investigates the optimal threshold value of failure rates for leased products with a Weibull lifetime distribution. Within a lease period, any product failure is rectified by minimal repairs and the lessor may incur a penalty when the time required to perform a minimal repair exceeds a reasonable time limit. To reduce product failures, additional preventive maintenance actions are carried out when the failure rate reaches a threshold value. Under this maintenance scheme, a mathematical model of the expected total cost is established. Based on the model, the optimal threshold value and the corresponding maintenance degrees are derived such that the expected total cost is minimized. The structural properties of the optimal policy are investigated and an efficient algorithm is provided to search for the optimal policy. Finally, numerical examples are given to illustrate the features of the optimal policy.

This paper investigates the effects of a free-repair warranty on the periodic replacement policy for a repairable product. Cost models are developed for both a warranted and a non-warranted product, and the corresponding optimal periodic replacement policies are derived such that the long-run expected cost rate is minimized. For a product with an increasing failure rate function, structural properties of these optimal policies are obtained. By comparing these optimal policies, we show that the optimal replacement period for a warranted product should be adjusted toward the end of the warranty period. Finally, examples are given to numerically illustrate the impact of a product warranty on the optimal periodic replacement policy.