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In this paper, a methodology for complex surface machining based on cutting forces prediction is presented. The work is focused on blade finishing operations. The cutting forces model developed can be applied to three axis and five axis milling cases. For three-axis cases, the chip thickness is calculated according to traditional analytical methods. On the contrary, for five-axis cases the chip thickness is obtained from a geometric method developed in the paper. The cutting forces values can be calculated for the complete toolpath, but the presented model can also provide the programmer information about the cutting forces in a single point of the toolpath. The cutting force model is integrated in the CAM software in order to provide an extra tool that helps the programmer to decide which the optimal milling strategy is, based on the minimum cutting forces. In the last section, results of a case study based on impeller and blisk blades flank milling are discussed. Model predicted forces and real measured...

Environmental pollutions caused by improper abandoned cartridges increase dramatically nowadays. In Hong Kong, due to abundant quantity of cartridges being used, producers have to optimise their forward and reverse networks to maximise the recycling rate and their profits. In this paper, a comprehensive closed-loop supply chain (CLSC) model is established. This model contains eight partners in CLSC and describes the existing cartridge recycling situation in Hong Kong. In the literatures, many CLSC models were established and studied, but few of them analysed the delivery activity for different kinds of materials extracted from the used products and also, few papers studied the situation that used products are classified into good and poor quality. In this model, delivery activities of different materials are considered and the used cartridges are classified into good-quality ones and poor-quality ones. Producers will have different methods to process them. This problem is formulated into an Integer progra...

Diverse customer desires coupled with technological advances have forced companies to manufacture products with ultimate performance, low cost, high quality and much shorter time-to-market. Recently, the popularity of smart phones has given rise to seriously declined product sales of digital cameras. In this paper, a two-phase framework is presented to offer decision supports on developing next-generation cameras. In the phase of market segmentation, Kansei engineering is employed to capture customer perceptions of affective features. Then, rough set theory is conducted to generate decision rules for partitioning the whole market into the consumer segment and the professional segment, respectively. In the phase of product customisation, conjoint analysis is applied to extract customer preferences for functional features. Furthermore, Grey relational analysis is conducted to select the top three varieties with regard to two distinct segments. In particular, this paper is capable to help brand companies or ...

This paper studies demand satisfaction and decision-making for a printed circuit board (PCB) manufacturing system. A performance indicator, the system reliability, is proposed to evaluate the demand satisfaction. In particular, two important characteristics, (i) multiple production lines in parallel and (ii) multiple repair actions, are considered in this study. The PCB manufacturing system is modelled as a stochastic-flow manufacturing network (SFMN) by the graphical transformation and decomposition techniques. Based on the network-structured SFMN, this paper develops an algorithm to generate all minimal capacity vectors that workstations should provide to satisfy a given demand. In terms of all minimal capacity vectors, the system reliability is derived. In addition, the reliable production policy is determined based on each single minimal capacity vector.

This paper proposes the implementation of demand response (DR) programmes in large manufacturing facilities featuring distributed wind and solar energy. Manufacturing facilities are high consumers of electric power. For this reason, these facilities usually pay exorbitant utility bills, which could be as much as $10–20 million per year. A high consumption of electricity also means that upstream fossil-fuelled power plants must release thousands of metric tonnes of carbon annually during the generation of electricity. DR contracts offer a lower utility rate in return for a load reduction during contingent events (i.e. peak hours). This paper covers the modelling and implementation of an interruptible/curtailable DR programme participated by a manufacturer that possesses onsite renewable generation units. These complementary energy resources allow the manufacturer to meet the curtailment requirements without causing any major electricity shortage that adversely affects the normal production schedule. We dev...

In an effort to achieve sustainable operations, green supply chain management has become an important area for firms to concentrate on due to its inherent involvement with all the processes that provide foundations to successful business. Modelling methodologies of product supply chain environmental assessment are usually guided by the principles of life cycle assessment (LCA). However, a review of the extant literature suggests that LCA techniques suffer from a wide range of limitations that prevent a wider application in real-world contexts; hence, they need to be incorporated within decision support frameworks to aid environmental sustainability strategies. Thus, this paper contributes in understanding and overcoming the dichotomy between LCA model development and the emerging practical implementation to inform carbon emissions mitigation strategies within supply chains. Therefore, the paper provides both theoretical insights and a practical application to inform the process of adopting a decision support framework based on a LCA methodology in a real-world scenario. The supply chain of a product from the steel industry is considered to evaluate its environmental impact and carbon ‘hotspots’. The study helps understanding how operational strategies geared towards environmental sustainability can be informed using knowledge and information generated from supply chain environmental assessments, and for highlighting inherent challenges in this process.

This paper studies the colour-batching problem frequently raised in automobile paint shops, where selectivity banks are used as storage and retrieval systems to execute practices of resequencing car bodies before painting operations are performed. The purpose of resequencing is to obtain colour-oriented batches of cars in order to reduce setup costs incurred in paint shops. In this paper, two heuristic procedures, arraying and shuffling heuristics, are developed aimed at quickly and effectively achieving good colour-batching results. The arraying heuristic can be applied in the car placing stage, while the shuffling heuristic can be utilised in the car releasing stage. Computational experiments are carried out to evaluate the performance of the proposed heuristics. It is shown that the shuffling heuristic can generate comparable car retrieval sequences with an exact branch & bound approach, and the proposed arraying and shuffling heuristics can be jointly applied to achieve good colour batching in a very ...

In recent years, interest on sustainable supply chain management (SSCM) has risen significantly in both the academic and business communities. This is confirmed by the growing number of conferences, journal publications, special issues and websites dedicated to the topic. Within this context, this paper reviews the existing literature related to decision-support tools and performance measurement for SSCM. A narrative literature review is carried out to capture qualitative evidence, while a systematic literature review is performed using classic bibliometric techniques to analyse the relevant body of knowledge identified in 384 papers published from 2000 to 2013. The key conclusions include: the evidence of a research field that is growing, the call for establishing the scope of current research, i.e. the need for integrated performance frameworks with new generation decision-support tools incorporating triple bottom line (TBL) approach for managing sustainable supply chains. There is a need to identify a wide range of specific industry-related TBL metrics and indexes, and assess their usefulness through empirical research and case-base analysis. We need mixed methods to thoroughly analyse and investigate sustainable aspects of the product life cycle across the supply chains, through empirical evidence, building and/or testing theory from and in practice. © 2014 © 2014 Taylor & Francis.

Order picking (OP) activities, essential to logistics operations, are laborious and time-intensive. Humans are central actors in the OP process and determine both OP effectiveness and efficiency. Many researchers have developed models for planning OP activities and increasing the efficiencies of such systems by suggesting different warehouse layouts, OP routes or storage assignments. These studies have, however, ignored workers’ characteristics, or human factors, suggesting that they cannot be substantiated, which led to only partially realistic results. This paper proposes a conceptual framework for integrating human factors into planning models of OP activities and hypothesises that doing so improves the performance of an OP system and workers’ welfare. The framework is based on a systematic literature review that synthesises findings documented in the OP and human factors literature. The results of the paper may assist researchers and practitioners in designing OP systems by developing planning models ...

The aim of this paper is to develop a comprehensive taxonomy of green supply chain management (GSCM) practices and develop a structural equation modelling-driven decision support system following GSCM taxonomy for managers to provide better understanding of the complex relationship between the external and internal factors and GSCM operational practices. Typology and/or taxonomy play a key role in the development of social science theories. The current taxonomies focus on a single or limited component of the supply chain. Furthermore, they have not been tested using different sample compositions and contexts, yet replication is a prerequisite for developing robust concepts and theories. In this paper, we empirically replicate one such taxonomy extending the original study by (a) developing broad (containing the key components of supply chain) taxonomy; (b) broadening the sample by including a wider range of sectors and organisational size; and (c) broadening the geographic scope of the previous studies. Moreover, we include both objective measures and subjective attitudinal measurements. We use a robust two-stage cluster analysis to develop our GSCM taxonomy. The main finding validates the taxonomy previously proposed and identifies size, attitude and level of environmental risk and impact as key mediators between internal drivers, external drivers and GSCM operational practices.

Value stream mapping (VSM) is a widely adopted method for transformation of production environments into a lean operational state. The straightforwardness as well as the completeness, with which processes are analysed and optimised, are key to the success of the method originating from the automotive industry. However, these attributes of the ‘paper and pencil’ approach result in limitations when applying VSM in complex production environments. This research paper targets to overcome these limitations, specifically in production environments involving significant demand variability, complex routing and cost factors which potentially increase with lean implementation. For this purpose, an enhanced VSM method is developed, which utilises discrete event simulation (DES). The method features a feasibility and trade-off analysis which is incorporated into the VSM procedure. A case study covering a process of exhaust gas purification catalyst production is then conducted to test the newly developed method. The ...

This paper proposes a framework for the continuous performance improvement of manned assembly lines for major appliances. The suggested framework consists of two main activities: (1) assembly work process improvement, including time and motion study and (2) improvement of line balance efficiency. Although there have been numerous studies on this topic, most of them deal with partial issues rather than the continuous performance improvement of the whole assembly line, which this paper addresses. To develop the framework, we categorised a manned assembly line into five analysis levels, (workstation, worker, operation cycle, work element and unit motion), and identified user requirements on each level. Among these five analysis levels, the workstation level supports line balancing, while the other four (worker, operation cycle, work element and unit motion) address work process improvement. The proposed framework has been implemented and tested with various examples from Korean assembly line based manufacturers.

Evidence suggests that lean methods and tools have helped manufacturing organisations to improve their operations and processes. However, the real effect of these methods and tools on contemporary measures of operational performance, i.e. cost, speed, dependability, quality and flexibility, is still unclear. This paper investigates the impact of five essential lean methods, i.e. JIT, autonomation, kaizen, total productive maintenance (TPM) and value stream mapping (VSM), on these measures. A linear regression analysis modelled the correlation and impact of these lean practices on the operational performance of 140 manufacturing organisations around the world. In addition, structural equation modelling (SME) was used to cross verify the findings of the regression and correlation analyses. The results indicate that JIT and automation have the strongest significance on operational performance while kaizen, TPM and VSM seem to have a lesser, or even negative, effect on it. This paper provides further evidence...

This paper addresses the problem of designing Make-to-Order (MTO) driven supply networks as is faced by producers of industrial goods. A major challenge in MTO network design is to estimate the operational performance of candidate networks. In particular, the stochastic and dynamic nature of order arrivals and fulfilment processes as well as the need to design a network that enables a timely delivery of ordered products complicate the decision-making. In this paper, a solution approach is presented where simulation is used for assessing the operational performance of candidate networks. The proposed simulation model captures multiple sources of uncertainties and incorporates fundamental control policies for reflecting the autonomous decision-making processes of operational planners. A Variable Neighbourhood Search (VNS) method is presented to guide the search for good network designs. Experiments are conducted on a set of multi-stage networks, where complex products are manufactured in MTO fashion and del...

Sustainable development (SD) will be the driving force to Twenty-first Century as automation was to the Twentieth Century and stream was to Nineteenth Century. There are two levels of sustainability: Macro-Level (country, cities) and Micro-Level (manufacturing enterprises and its town and regional areas). In this paper, Micro-Level of sustainability will be discussed. The major challenge of manufacturing enterprises is modelling and assessing the sustainable development performance. Introducing indexes for sustainable development assessment in manufacturing enterprises is important not only to enable them to quantitatively estimate SD, but also to determine the requirements of components for these enterprises to survive. The main objectives addressed in this paper is how to model the required components and how to introduce a new assessment framework for assessing sustainability from lowest levels, dimensions up to sustainable development level according to Micro-Level. The three pillars of sustainability...

The paper attempts to develop a resubmitted sampling scheme by variables inspection for controlling lot fraction nonconforming when the quality characteristic follows a normal distribution and has two-sided specification limits. In this paper, the plan parameters are determined by the classical two-point condition on the operating characteristic curve, which will satisfy the quality requirements and allowable risks by the producer and the consumer simultaneously. The behaviour of the proposed sampling plan is discussed and compared with the conventional single sampling plan by variables. The proposed plan requires smaller sample size for inspection with the same protection to the producer and the consumer especially when the quality of the submitted lot is good enough. Tables of the plan parameters under several selected quality requirements and risks are provided for practical applications, and the operating procedure is also presented and illustrated with an example.

This paper uses a systematic review to answer two research questions: (1) has this large number of performance measurement systems (PMS) publications contributed to a better understanding of performance measurement? and (2) what would a better understanding of PMS lead us to? This paper found that the field has not evolved substantially for the past 30 years. While various PMS are discussed and proposed, there are many instances of a common ground on what were discussed but in a few instances, there is little to no agreement concerning the activities and characteristics used to describe them, and there is also a great deal of overlap in the meaning of definitions and terms. Nevertheless, the synthesis review revealed that many of the discussions of the fundamental characteristics useful and in certain cases, interesting and insightful. Research gaps were identified and narrowed by synthesising instances of a common ground, and if a common ground is not forthcoming, references to non-PMS articles were made...

The progression of capabilities according to the sand cone model is a commonly accepted notion in production and operations management. However, this progression, which implies development over time, has only been tested with cross-sectional data from single time periods. In this paper, we investigate competitive capability progression (CCP) using a repeated cross-sectional design, approximating the temporal dimension inherent in the concept. The contributions of our paper are threefold. First, we test whether the sand cone model of CCP can be replicated in a repeated cross-sectional design. Second, we examine the cumulative reinforcement patterns among capabilities by investigating the links between them, thereby assessing the robustness of the configuration prescribed by the sand cone model over time. And third, we examine whether the configurations in which cumulative capabilities are pursued differ across the two time periods, and how they influence improvements in manufacturing plant performance.

This paper considers some of the changes in thinking and the resulting paradigm shifts which have influenced the nature of business since the International Journal of Production Research was first published in 1961, and which have significantly transformed the productivity of industry and the quality of its goods and services. Rather than speculating on the likely paradigm shifts over the next 50 years, the paper considers some of the current social and economic pressures which are likely to contribute to future changes.

Research into moderators, which support collaborative teams by proactively making team members aware of actions or potential problems which may affect them, began in the 1990s, in the context of supporting collaborations during concurrent engineering projects. This paper provides a background to the evolution of moderators and explores their role in supporting virtual organisations. A collaboration moderator (CM) is an evolution of earlier moderators and is capable of behaving differently for different types of users and therefore caters for the varying requirements of individual users depending on the roles they have in the collaborations. This paper describes the architecture and components of a CM from an implementation perspective. Prototype CMs have been developed during the EU-funded SYNERGY project, and two use cases for which the prototype CMs were implemented as a service (a Pre-Creation use case and an Operational use case) are also discussed in this paper.

Eco-design is becoming a crucial challenge for many companies. The effective integration of environmental concerns into design is linked to the development of Knowledge Management Systems (KMS). In this context, this paper proposes a framework to support the design of KMS for eco-design. This framework consists of two complementary parts linked to the main knowledge management strategies that KMS generally support. The first part of the framework concerns codification strategy and relies on an eco-design process reference model and the related adaptation of the GAMETH® method used to locate and evaluate crucial knowledge systematically. The second part of the framework concerns the personalisation strategy. In this paper we propose to exploit the community of practice (CoP) theory by: (1) proposing guidelines defining the structural features of CoPs and (2) adapting a tool landscape providing insight on CoP instrumentation. Both guidelines support the setting up of a specific CoP. The exploitation of the ...

This paper addressed the order tracking and allocation problem in an apparel manufacturing environment with multiple plants. A cloud-based intelligent decision-making system was developed to tackle this problem, which combined radio frequency identification and cloud computing technologies to capture real-time production records and make remote production order tracking, and employed computational intelligence techniques to generate effective order allocation solutions to appropriate plants. To evaluate the effectiveness of the proposed system, the system was implemented in an apparel manufacturing company with multiple plants, which reported distinct reductions in production costs and increases in production efficiency. This paper also investigated learning phenomenon in production and its effects on production efficiency and decision-making performance.

This paper builds on the original five focusing steps as defined by Goldratt and Cox (1992) as one of the constructs of the theory of constraints (TOC). The shortcomings identified are the sequential nature suggested by the five seemingly sequential steps, the lack of clarity relating to decisions that allows moving to next or previous steps, the assumed inapplicability of the five steps to dealing with market- and non-physical constraints (such as policy and behavioural constraints) and the lack of clarity surrounding an ideal constraint location. Deductive reasoning is applied to existing literature to arrive at conceptual solutions to the identified problems. The paper transforms the five focusing steps into a decision map which still includes all five steps, but allowing appropriate decision points to guide application of this process. It expands the applicability of the five focusing steps to both market and non-physical constraints, as well as presenting a logical argument why the best possible cons...

This paper suggests a new technique to facilitate consistent transition between planning and production stages of small lots of complex products (in quantities that do not justify full automation). Despite the usage of modern approaches such as design for assembly and design for manufacturing the typical product planning ends up before production planning begins, instead of having a unified seamless planning process. This paper presents a new three stage technique to fill the gap between product planning and production. The paper shows how to generate a rigorous production plan by: (1) extending the Bill-of-Materials to include additional required information, (2) constructing an assembly ‘method prototype’ and (3) using the ‘method prototype’ to calculate time standards for executing the assembly. A case study illustrates the proposed technique.

This study is dedicated to strategic decision-making regarding order penetration point (OPP), which is the boundary between make-to-order (MTO) and make-to-stock (MTS) policies. This paper considers a supply chain in which a manufacturer produces semi-finished items on an MTS basis for a retailer that will customise the items based on MTO policy. This two-echelon supply chain offers different products to a market comprised of homogenous customers who have different preferences and willingness to pay. The retailer wishes to determine the optimal OPP, the optimal semi-finished goods buffer size, and the price of the products with assumption of price sensitive demand function. Moreover, we consider both shared and unshared capacity models in this paper. A matrix geometric method is utilised to evaluate various performance measures for this system, and then, optimal solutions are obtained by enumeration techniques. The suggested queuing approach is based on a new perspective between the operations and marketi...

This paper considers the precast production problem with identical parallel molds. To produce precast elements, multiple processes including mold preparing, concrete mixing, curing, stripping and finishing must be completed in a mold. Some processes require an additional resource shared among molds. All the processing times are constant except the curing time, which increases when using a more expensive concrete mixing formula. Given a demand and a production time frame, this paper proposes a heuristics to select concrete formulas and schedule jobs to minimise the total product cost. A mixed integer programming (MIP) model is formulated to solve for the optimal solutions. The results demonstrate that the proposed heuristics finds the same optimal solutions as obtained from the MIP model but with many orders of magnitude less than computational times. In the problems where the MIP model cannot find the optimal solutions due to the problem complexity, the proposed heuristics can find feasible solutions that...

The overall context of this paper is the parameterisation of the material requirement planning method. It is crucial to be able to evaluate the potential effects of the parameters on the production system’s performance indicators (PI). This evaluation is generally the result of the combination of an experimental design with a production system simulator. This paper proposes an approach facilitating the interpretation of the effects of the experimental design method. The specific feature of our approach is that it proposes the classification of the effects as a model for the automatic identification and extraction of the properties. These characterise the relations between the parameters and the PI.

This paper discusses mechanisms for the allocation of emission permits (AEP) among a group of manufacturing companies aiming at controlling the total emission level of the group. Data envelopment analysis is adopted and extended to construct the AEP models. Proposed methods allocate the permits on the basis of the current input and output levels of individual firms, rather than historical records. Two variations of AEP mechanisms are considered. One situation is that one of the member firms dominates the responsibility of allocating emission permits on behalf of the group (individual AEP scenario). This dominating firm will maximise its own emission permit before allocating permits among other members in the group. The other situation is that a third-party central governing body is centrally responsible for coordinating the AEP among all group members (Central AEP scenario). Proposed mechanisms are applied to analyse efficiencies of a group of paper mills. The result shows that the mode of central AEP mec...

In this paper, we consider the problem of using empirical continuous-state wear data of machine tools to estimate the dynamic lifetime distribution and to measure the performance of a machining process subject to stochastic tool-wear evolution. Machining systems are dynamic processes whose performance variable is usually characterised by the amount of tool wear that advances gradually with a continuous range of values. To accurately capture the performance of these continuous-state wear processes, neither traditional models such as the binary-state models nor multi-state models are suitable. In this paper, an exponential mixed-effects (EME) model is first developed. The EME model is subsequently transformed into a linear mixed-effects (LME) model to enhance the fit and predictability of the wear process data. The LME models take into consideration the correlations among repeated wear measurements collected at different time points within each subject. We then implement the expectation-maximisation (EM) al...

Manufacturing systems producing multiple products are common in many industries, where products are made from several parts and/or sub-assemblies that require machining operations in first stage and assembly operations at later stage. Several scheduling techniques are proposed in the literature for such manufacturing system to develop near optimal schedule. A disruption in the manufacturing necessitates adjusting previously planned schedule which is known as real-time scheduling. This paper presents a comparative evaluation of different scheduling methods proposed by different investigators for dealing such situations. The literature indicates that real-time scheduling of manufacturing system with machining and assembly operations is hardly attempted. The paper offers a framework for developing rescheduling methodologies for such manufacturing situations.

Modelling the dimensional variation propagation in multi-station machining processes (MMPs) has been studied intensively in the past decade to understand and reduce the variation of product quality characteristics. Among others, the Stream-of-Variation (SoV) model has been successfully applied in a variety of applications, such as fault diagnosis, process planning and process-oriented tolerancing. However, the current SoV model is limited to the MMPs where only fixtures with punctual locators are applied. Other types of fixtures, such as those based on locating surfaces, have not been investigated. In this paper, the derivation of the SoV model is extended to model the effect of fixture- and datum-induced variations when fixtures with locating surfaces are applied. Due to the hyperstatic nature of these fixtures, different workholding configurations can be adopted. This will increase the dimension of the SoV model exponentially and thus may make the model-based part quality prediction extremely complex. This paper presents a method of reducing the complexity of the SoV model when fixtures based on locating surfaces are applied and evaluates the worst-case approach of the resulting part quality.

A new concept is presented in this paper of quasi-dynamic cell formation for the design of a cellular manufacturing system, based on analysing the fact that static and dynamic cell formation could not reflect the real situation of a modern cellular manufacturing system. Further, workforce resources are integrated into quasi-dynamic cell formation and thus a quasi-dynamic dual-resource cell-formation problem is proposed. For solving this problem, this paper first establishes a non-linear mixed integer programming model, where inter-cell and intra-cell material cost, machine relocation cost, worker operation time, loss in batch quality and worker salary are to be minimised. Then, a multi-objective GA is developed to solve this model. Finally, a real life case study is conducted to validate the proposed model and algorithm. The actual operation results show that the case enterprise significantly decreases its material handling cost and workforce number and obviously increases its product quality after carryi...

In this paper, a novel model for a deteriorating manufacturing system is analysed, considering repairs and overhauls of random durations. The machine manufactures one product and the model is further complicated because the quality of the parts’ produced deteriorates according to the wear of the machine and human interventions. When a breakdown occurs, either a repair or an overhaul is performed. The machine is restored to as-good-as-new conditions if the overhaul is selected, and conversely, its condition deteriorates following repairs. Multiple operational states are considered to define an ageing process. The decision variables of the model are the production rate and the repair/overhaul switching strategy. This paper provides new insights to this research area by considering the simultaneous production and repair/overhaul control policy under the effect of deteriorations. The optimal decision policy minimises the total incurred cost comprising the inventory, backlog, repair and overhaul costs over an ...

The level scheduling problem is concerned with the final stage of a multi-stage just-in-time production system so that different models of a product are evenly distributed in a discrete production sequence, thereby making the problem practically an unconstrained optimisation problem. The car sequencing problem, on the other hand, is a constraint satisfaction problem based on a number of options constricting the final assembly schedule. The combined car sequencing and level scheduling problem aims to find the optimal production schedule that evenly distributes different models over the planning horizon and satisfies all option constraints. This paper proposes a parametric iterated beam search algorithm for the combined problem that can be used either as a heuristic or as an exact optimisation method. The paper includes a computational study based on a 54-instance test bed that proves the effectiveness of the proposed algorithm.

Manufacturing and supply chain flexibility has been discussed extensively in the scientific literature. Given the different definitions, types and dimensions of flexibility, the purpose of this paper is to explore the origins and structure of the scientific research on manufacturing and supply chain flexibility. We identified a sample of 153 internationally published papers and conducted a citation analysis to examine the connections between the many scientific papers and to explore the most influential works and their impact on flexibility research. Our analysis revealed that research on flexibility received the most scientific attention between 1996 and 2005. However, the majority of the currently valid types and dimensions of flexibility have been defined in the late 1980s and the early 1990s. The current paper provides the leading academic journals and papers in the field of flexibility research. Additionally, the results of our citation analysis indicate that flexibility research is significantly inf...

This paper proposes to use a Petri net framework together with simulation technology to model and analyse distributed manufacturing networks. With the distinct modelling features of Petri nets, this study has the ability to identify and evaluate the potential quality risks in distributed manufacturing systems. The risks can be migrated from an upstream to downstream process. The proposed approach involves a qualitative risk analysis methodology which integrates risk identification, analysis and mitigation actions to evaluate distributed system risks. A Monte Carlo simulation was used to model risk parameters and realise how the mitigation process can help minimise risk through numerical analysis. Hence, with basic statistical concepts, the key performance variables and the risk factors of distributed manufacturing systems are analysed. In this paper, the detailed components in the proposed workflow are illustrated with a case example to realise the feasibility of application in an industrial environment. ...

Product platform development (PPD) as an approach to mass customisation (MC) helps an organisation to reduce costs as well as ensure timely deliveries. Varieties are offered to different market segments by combining and incorporating different modules at different levels. Modules at different levels are essentially features that a customer segment is looking for. It is apparent that overall optimisation would require simultaneous consideration of not only PPD but also other supply chain constraints. In this paper, an attempt has been made to develop a mixed integer linear programming (MILP) model for sourcing, production planning, and PPD decisions. Based on analyses of the model, a heuristic solution procedure has been suggested. The heuristic developed in this paper attempts to decompose the problem and then assimilate the outputs from the simpler parts to obtain the final solution. Finally, a simple example to illustrate the solution procedure is presented.

This paper describes the development of flexibility through my personal views and involvement in researching this complex concept. It differentiates between two modelling perspectives: the bottom-up perspective (from the flexibility of elements to integrated flexibility) of the early researchers for modelling flexible manufacturing systems (FMSs) and the more recent top-down perspective, from flexibility as a strategy to resources needed for implementing it. The bottom-up perspective is represented here by three papers. One paper focuses on Petri nets as a modelling tool, another offers a multi-factor design of experiments (DOE) view on factors affecting the performances of an FMS, and the third one presents a framework of logistic flexibility. The top-down perspective focuses on supply chain flexibility and uses quality function deployment (QFD) as a hierarchical modelling technique. An original framework for analysing the flexibility of generic objects, utilising cloud diagrams, is also presented. In al...

Full turnover-based storage has been widely claimed to outperform the commonly used ABC class-based storage policy in terms of the resulting storage and retrieval travel time. In the first paper describing the full turnover-based policy, simultaneously implicitly assuming shared storage (that is to say storage space that can be used by other products once the original product's inventory is depleted) was modelled, since no specific space was reserved to store the maximum inventory of a product. However, full turnover-based storage is a dedicated storage policy where the storage space allocated to one product must be able to accommodate its maximum inventory level. Since then, many authors have cited the results of the full turnover-based storage policy while often overlooking its incompatible shared-storage assumption. This paper adapts classic travel time models to accommodate full turnover-based dedicated storage. We consider different warehousing system configurations such as square-in-time (SIT) and non-SIT racks, and speed acceleration and deceleration effects to calculate the storage/retrieval (S/R) machine's travel time. Surprisingly, but in line with practice, the results of the adapted travel time models show that random and class-based storage normally outperform full turnover-based storage.

Multi-pass milling is a common manufacturing process in practical production. Parameter optimisation is of great significance since the parameters largely affect the production time, quality, cost and some other process performance measures. However, the parameter optimisation of the multi-pass milling process is a nonlinear constrained optimisation problem. It is very difficult to obtain satisfactory results by the traditional optimisation methods. Therefore, in this paper, a new optimisation technique based on the electromagnetism-like mechanism (EM) algorithm is proposed to solve the parameter optimisation problem in a multi-pass milling process. The EM algorithm is a population based meta-heuristic algorithm for unconstrained optimisation problems. As the parameter optimisation problem is a constrained problem, the proposed approach handles the constraints of the problem by improving the charge calculation formula combined with the feasibility and dominance rules at the same time. This paper also puts...

The traditional production model development assumed that all products are perfect quality and did not consider maintenance, which is far from reality. In practice, the production process may shift randomly from an in-control state to an out-of-control state during a production run, i.e. process deterioration. This paper considers both preventive maintenance and corrective maintenance which are used to increase the system reliability. The objective of this paper is to determine the optimal production run time and maintenance frequency while minimising the total cost under process deterioration and trade credit. This paper develops a theorem and an algorithm to solve the problem described, provides numerical analysis to illustrate the proposed solution procedure, and discusses the impact of various system parameters. A real case of hi-tech manufacturer is used to verify the model. It predicts a 10.36% decrease in total cost if the preventive maintenance decision is considered.

For a discrete-part manufacturing process, adjustment is necessary to bring the process to target when the setup of the machine is improperly done. This paper investigates the adjustment scheme for a multivariate process with initial offset in the presence of fixed adjustment cost. The objective is to derive a solution for the case that the cost for different responses can be different. Based on the state process-control model, expressions of optimal adjustment scheme are derived by the dynamic programming and congruent transformation of quality loss matrix. This scheme belongs to a deadband form and calls for an adjustment only when the norm of the linear transformation of perceived process mean vector is at the outside of the deadband. A simulation study is conducted to compare the scheme proposed in this paper with two other schemes.

This paper considers a production problem for a transfer line subject to random failures and repairs, and differs from other studies on transfer lines. It considers a manufacturing system consisting of three machines (two machines with passive redundancy, and one in series with the previous ones) producing one part type. The control problem is subject to non-negative constraints on work-in-process (WIP). The decision variables are the production rates of two main machines and a standby machine, and influence the WIP levels, the inventory levels and the system's capacity, which is assumed to be described by a finite-state Markov chain. The objective of this paper is to minimise WIP and finished goods inventory costs; it also aims to respect the essential space–time during intervention on machine down, in order to minimise the possibility of the circumvention of protection devices or of the retraction of lockout/tagout procedures through a passive redundancy system. This paper therefore verifies the effect ...

This paper presents a critical and focused review of definitions, challenges and developments of the workforce allocation system in manufacturing shop floors with a particular emphasis on response to changes and disturbances. The continuously changing requirements in production environments have been the driving force behind several stages of evolution experienced by management of workforce allocation. The paper includes an in-depth examination of the phenomena of changes and disturbances in the production shop floor. This is followed by an assessment of the readiness of workforce allocation systems to respond to such events with respect to both workforce perception and system architecture. Recent developments of the workforce allocation models suggest that the use of intelligent and distributed systems and techniques offer solutions that are responsive, flexible, and multi-criteria. To this end, an overview of a recent study in the application of the principles of holonic manufacturing systems, as an exa...

In the context of in-plant materials supply, the materials feeding principle of kitting is often discussed as an alternative to the more common continuous supply (also known as line stocking). However, there are few detailed studies describing the relative effects of kitting and continuous supply. The current paper identifies the relative effects of kitting and continuous supply, and provides insight into how these effects arise. The paper draws on empirical data from two case studies in the Swedish automotive assembly industry. In each of the cases, continuous supply has been replaced by kitting, enabling comparison of kitting and continuous supply in the same production environment. The performance areas studied include man-hour consumption, product quality, flexibility, inventory levels, and space requirements. Interviews with production engineers, assemblers, and operators responsible for kit preparation at each company contribute to a broad yet detailed view of the relative effects of the two materials feeding principles.

This paper reviews the broad range of literature related to sustainable manufacturing published in the International Journal of Production Research (IJPR) over the past 50 years. It establishes research frontiers and contributions in the topic of sustainable manufacturing and the related impact to environmental sustainability. With the growing concern of the environmental impact of factors such as pollution and waste, the research areas of sustainable manufacturing and efficient resource utilisation have become significantly more important over the last decade. Whereas early papers focused on safety, workplace, design, and process improvements, research today focuses on ergonomics, intelligence, global manufacturing, environmental challenges, design for sustainability, product life cycle management, and green supply chain management. The paper also briefly surveys existing approaches and identifies commonly used analytical tools and methodologies.

In lean manufacturing, milk run (MR) systems represent route-based, cyclic material handling systems that are used widely to enable frequent and consistent deliveries of containerised parts on an as-needed basis from a central storage area (the ‘supermarket’) to multiple line-side deposit points on the factory floor. In the first part of this two-part paper, a basic, single-tugger MR system is described, and stability conditions as well as the probability of exceeding either the physical capacity of the tugger or the prescribed cycle time are derived. Given the stability conditions, and the distribution of the number of containers requested per MR, in the second part of the paper, the number of Kanban required in the MR system is examined, and analytical approximations are derived both for the number of Kanban required and for predicting workstation starvation. The latter is a key concern when designing a MR system that will support workstations in a manufacturing plant. The performance of the analytic ap...

Production control policy and economic sampling plan design problems have been studied separately in previous research. This paper considers a joint production control policy and economic single sampling plan design for an unreliable batch manufacturing system. The production is controlled by a modified hedging point policy which consists in building and maintaining a safety stock of finished product to avoid shortages during corrective maintenance. The main objective of this paper is to determine simultaneously the economic production quantity, the optimal safety stock level and the economic sampling plan design which minimize the expected overall cost. A stochastic mathematical model is developed and solved using a simulation optimization approach based on the response surface methodology. Simulation is used to imitate the complex dynamic and stochastic behaviour of processes as in the real-life industrial systems. The obtained results show clearly strong interactions between production quantity, inventory state and sampling plan design which confirm the necessity of jointly considering production and quality control parameters in an integrated model. Moreover, it is shown a significant impact of production system reliability on the economic sampling plan design and therefore on the quality of finished product delivered to consumers. Numerical example and sensitivity analyses are presented for illustrative purposes.

Failure mode and effect analysis (FMEA) is an important method for designing and prioritising preventive maintenance activities and is often used as the basis for preventive maintenance planning. Although FMEA was studied extensively, most of the published work so far covers FMEA concept design. Little detailed comparison to industrial practice regarding the application of FMEA can be found in the literature, which is the contribution of this study. This paper summarises the main descriptions and assumptions found in the literature on FMEA into six postulates, and compares the postulates to industrial practice. This was done in a multiple case study conducted at six companies in the process industry. Some postulates were supported by empirical evidence, whereas for others, limited or no support could be found. The results suggest a fundamental problem in the FMEA procedure, namely, the reliance upon expert judgement in general and the reliance upon design engineering expertise for keeping the FMEA up-to-date in particular. Also, a number of operational and information management problems that companies suffer from when conducting an FMEA were identified. Practitioners can use this paper to assess their potential for implementing FMEA and to learn from the insight into the identified pitfalls. Researchers can use the findings to guide further work on improving and developing the FMEA procedures.