Showing papers in "International Journal of Production Research in 1991"
TL;DR: In this article, a linear zero-one formulation was proposed to solve the machine-part group formation problem in cellular manufacturing systems, where the integrality conditions of the proposed formulation can be relaxed.
Abstract: The machine-part group formation is an important issue in the design of cellular manufacturing systems. The present paper first discusses some of the alternative formulations of this problem, their advantages and disadvantages, and then suggests a new linear zero-one formulation which seems to have removed most of the disadvantages observed in other models. It will be shown that most of the integrality conditions of the proposed formulation can be relaxed. This considerably improves its computational feasibility and efficiency. Finally, a simulated annealing approach to deal with large-scale problems is also presented.
332 citations
TL;DR: By utilizing this decision algorithm, the decision-makers’ fuzzy assessments with various rating attitudes and the trade-off among various selection criteria can be taken into account in the aggregation process to asssure more convincing and accurate decision-making.
Abstract: In this paper, a facility site selection algorithm is proposed. The algorithm based on the concepts of fuzzy set theory and the hierarchical structure analysis to aggregate decision-makers’ linguistic assessments about criteria weightings and the suitability of facility sites versus various selection criteria to obtain fuzzy suitability indices. Then rank the suitability ratings to determine the best facility site selection. By utilizing this decision algorithm, the decision-makers’ fuzzy assessments with various rating attitudes and the trade-off among various selection criteria can be taken into account in the aggregation process to asssure more convincing and accurate decision-making.
247 citations
TL;DR: The just-in-time (JIT) literature is reviewed to identify 211 refereed articles as discussed by the authors to examine the significance of JIT implementation, global productivity comparison articles are summarized.
Abstract: The just-in-time (JIT) literature is reviewed to identify 211 refereed articles. To examine the significance of JIT implementation, global productivity comparison articles are summarized. The JIT, MRP and OPT comparisons research is examined. Classification of the JIT-practices-articles according to the topic areas is presented. Critical variables, discussed in the JIT implementation in manufacturing articles, are classified according to the four basic tenets of the JIT philosophy. Eleven critical variables are identified for the elimination of waste tenet. For employee involvement in decision-making, supplier participation and total quality control tenets, five, ten, and eight critical variables, respectively, are listed. To ensure a comprehensive review of the JIT literature, an extensive bibliography and some reviews of books on the JIT philosophy are provided. Future research directions are discussed.
222 citations
TL;DR: This paper presents an efficient algorithm for finding conflict-free shortest-time routes for automated guided vehicles moving in a bidirectional flow path network based on Dijkstra's shortest-path method, and introduces the concept of time window graph.
Abstract: This paper presents an efficient algorithm for finding conflict-free shortest-time routes for automated guided vehicles moving in a bidirectional flow path network. The proposed algorithm is based on Dijkstra's shortest-path method. It maintains, for each node, a list of time windows reserved by scheduled vehicles and a list of free time windows available for vehicles to be scheduled. We introduce the concept of time window graph in which the node set represents the free time windows and the arc set represents the reachability between the free time windows. Then the algorithm routes the vehicles through the free time windows of the time window graph instead of the physical nodes of the flow path network. It requires O(v4n2) computations in the worst case, where v is the number of vehicles and n is the number of nodes.
215 citations
TL;DR: An efficient non-hierarchical clustering algorithm, based on initial seeds obtained from the assignment method, for finding part-families and machine cells for group technology (GT) is presented in this article.
Abstract: An efficient nonhierarchical clustering algorithm, based on initial seeds obtained from the assignment method, for finding part-families and machine cells for group technology (GT) is presented. By a process of alternate clustering and generating seeds from rows and columns, the zero-one machine-component incidence matrix was block-diagonalized with the aim of minimizing exceptional elements (intercell movements) and blanks (machine idling). The algorithm is compared with the existing nonhierarchical clustering method and is found to yield favourable results.
215 citations
TL;DR: A formulation and solution of a multi-objective optimization problem for the selection of the best control settings on a wire electrical discharge machine is presented and the concept of a non-dominated point is introduced.
Abstract: This paper presents a formulation and solution of a multi-objective optimization problem for the selection of the best control settings on a wire electrical discharge machine. The measures of performance for the model are taken to be metal removal rate and surface finish quality. A factorial design model is used to predict the measures of performance as a function of a variety of control settings. To aid in selecting the best combination of settings the concept of a non-dominated point is introduced. The non-dominated points are related to two important complementary optimization problems. Two techniques for the computation of non-dominated points are presented—one using explicit enumeration and the other based on the principles of dynamic programming.
206 citations
TL;DR: An efficient approach for a computer-based solution to the problem of selection of an ‘optimum robot’ specifically to aid industries by applying Multiple Attribute Decision Making (MADM) ideology to equipment selection (robots).
Abstract: This paper presents an efficient approach for a computer-based solution to the problem of selection of an ‘optimum robot’ specifically to aid industries. The approach breaks new ground by applying Multiple Attribute Decision Making (MADM) ideology to equipment selection (robots) which is of consequence because selection is an implicit aspect of design. Indeed, the approach is also applicable to a robot design problem. The robot selection procedure allows rapid convergence from a very large number to a manageable shortlist of potentially suitable robots using an ‘elimination search’ routine based on a few pertinent attributes of the robots. Subsequently, the selection procedure proceeds to rank the alternatives in the shortlist by employing a MADM method termed TOPS1S (Technique for Order Preference by Similarity to Ideal Solution). An expert system has been developed as part of the software package to assist an inexperienced user to establish priorities, and to ‘oversee’ the selection process at ...
179 citations
TL;DR: In this paper, a "close neighbor algorithm" is proposed to solve the problem of visual identification of machine groups and part families in cellular manufacturing systems, which overcomes many deficiencies of the CDR and ASM methods.
Abstract: The first step in creating a cellular manufacturing system is to identify machine groups and form part families. Clustering and data organization (CDR) algorithms (such as the bond energy algorithm) and array sorting (ARS) methods (such as the rank order clustering algorithm) have been proposed to solve the machine and part grouping problem. However, these methods do not always produce a solution matrix that has a block diagonal structure, making visual identification of machine groups and part families extremely difficult. This paper presents a ‘close neighbour algorithm’ to solve this problem. The algorithm overcomes many deficiencies of the CDR and ASM methods. The algorithm is tested against ten existing algorithms in solving test problems from the literature. Test results show that the algorithm is very reliable and efficient.
170 citations
TL;DR: Approximate solution algorithms are developed to find a minimum makespan schedule in a two-stage hybrid flow shop when the second stage consists of multiple identical machines in this article, where the proposed heuristic algorithms can be used to improve the efficiency of an existing branch and bound algorithm.
Abstract: Approximate solution algorithms are developed to find a minimum makespan schedule in a two-stage hybrid flowshop when the second stage consists of multiple identical machines. Computational experience comparing the ‘approximate’ makespans with their respective global lower bounds for large problems indicates that proposed polynomially bounded approximate algorithms are quite effective. It is shown that the proposed heuristic algorithms can be used to improve the efficiency of an existing branch and bound algorithm.
148 citations
TL;DR: In this article, an efficient heuristic programming procedure for evaluating alternative discount schedules is proposed. But this procedure is not suitable for the case of multiple items, resource limitations and multiple suppliers.
Abstract: This research considers quantity discount procedures under conditions of multiple items, resource limitations and multiple suppliers. This is a very complex problem that has not yet been addressed in the literature. In this paper we offer an efficient heuristic programming procedure for evaluating alternative discount schedules. Moreover we use an example problem to test the suggested procedure. The results offer several encouraging findings for managers facing this impressive problem.
142 citations
TL;DR: In this paper, a fuzzy c-means clustering algorithm is proposed to formulate the problem of cellular cell formation, which not only reveals the specific part family that a part belongs to, but also provides the degree of membership of a part associated with each part.
Abstract: Cell formation, one of the most important problems faced in designing cellular manufacturing systems, is to group parts with similar geometry, function, material and process into part families and the corresponding machines into machine cells. There has been an extensive amount of work in this area and, consequently, numerous analytical approaches have been developed. One common weakness of these conventional approaches is that they implicitly assume that disjoint part families exist in the data; therefore, a part can only belong to one part family. In practice, it is clear that some parts definitely belong to certain part families, whereas there exist parts that may belong to more than one family. In this study, we propose a fuzzy c-means clustering algorithm to formulate the problem. The fuzzy approach offers a special advantage over conventional clustering. It not only reveals the specific part family that a part belongs to, but also provides the degree of membership of a part associated with each part...
TL;DR: In this article, a solution procedure for solving the joint replenishment problem using a basic cycle approach is provided, which involves comparing possible values between the "minimum" and "maximum" cycle times.
Abstract: A solution procedure is provided for solving the joint replenishment problem using a basic cycle approach. The solution procedure is very simple, and involves comparing possible values between the ‘minimum’ and ‘maximum’ cycle times. Extensive simulation demonstrates that this solution procedure is superior to previously known algorithms for solving this problem.
TL;DR: In this article, the authors present two new dynamic due-date assignment rules which utilize shop congestion information to estimate job flowtime based on a sampling of recently completed jobs, and evaluate the robustness of the rules, using an experimental design with three different queue sequencing heuristics and two different shop balance levels.
Abstract: This paper presents two new dynamic due-date assignment rules which utilize shop congestion information. The new rules estimate job flowtime based on a sampling of recently completed jobs. These rules are compared with other established flowtime estimate models on the criterion of due-date performance via computer simulation. To evaluate the robustness of the rules, an experimental design with three different queue sequencing heuristics and two different shop balance levels was used. The results of this investigation clearly indicate that flowtimes from recently completed jobs provide very useful information for establishing effective due-dates in a job shop environment. In addition it is shown how the use of particular sequencing rules greatly increases the precision of flowtime estimates.
TL;DR: In this paper, the formation of machine and part groups is a central issue in the design of cellular manufacturing systems, and the Hamiltonian path problem is used to form a distance measure for machines and parts.
Abstract: The formation of machine and part groups is a central issue in the design of cellular manufacturing systems. The part-machine incidence matrix has formed the basis of several techniques for cell formation. In this paper, we propose formulating machine and part ordering as a Hamiltonian Path Problem. Similarity coefficients are used to form a distance measure for machines and parts. The resulting solutions are shown to be better than those obtained from binary clustering on a set of test problems.
TL;DR: In this paper, the authors describe the design and development of an analytical tool for the selection of machine parameters in turning, which is used to determine values for machine speed and feed that minimize the total cost of machining; specifically the costs associated with machining time and cutting tool wear.
Abstract: This paper describes the design and development of an analytical tool for the selection of machine parameters in turning. The problem is to determine values for machine speed and feed that minimize the total cost of machining; specifically the costs associated with machining time and cutting tool wear. Geometric programming is used as the basic methodology, and the solution approach for the selection of machine parameters is based on an analysis of the complementary slackness conditions and realistic machining conditions. The quality of the solution is illustrated on several examples and compared to solutions obtained by some optimization methods proposed in the literature. In general, our technique is simple and straightforward and indicates how sensitive the solution is to the machine power consumed and surface finish attained.
TL;DR: In this paper, a visual interactive decision support framework designed to aid the decision-maker, typically top management, in selecting the most appropriate technology and design when planning a flexible manufacturing system (FMS) is described.
Abstract: A visual interactive decision support framework designed to aid the decision-maker, typically top management, in selecting the most appropriate technology and design when planning a flexible manufacturing system (FMS) is described. The framework can be used in the preinvestment stage of the planning process, after the decision in principle has been made to build an FMS. First, both qualitative and quantitative criteria are used to narrow the set of alternative system configurations under consideration down to a small number of most attractive candidates. After this prescreening phase, a multiobjective programming model is formulated for each remaining configuration, allowing the manager to explore and evaluate the costs and benefits of various different scenarios for each configuration separately by experimenting with different levels of batch sizes and production volumes. The system uses visual interaction with the decision-maker, graphically displaying the relevant trade-offs between such relevant perfo...
TL;DR: In this article, the authors expand the cost concept to include quality and flexibility, which are critical factors for performance evaluation and project justification of advanced manufacturing systems, and present a quantitative method of estimating the cost elements.
Abstract: As manufacturers continue to automate their factories, they discover that existing cost measures should be updated. Much of the existing literature has discussed the ‘why's’ but there is little about the ‘how's’. This paper expands the cost concept to include quality and flexibility because they are critical factors for performance evaluation and project justification of advanced manufacturing systems. Then, a quantitative method of estimating the cost elements is illustrated. Finally, various approaches to collecting parametric values of the cost model and applications of the cost model are presented.
TL;DR: In this paper, a multistage production/inventory system is modelled as a Markov Decision Process (MDP), combining of just-in-time (pull) and MRP (push) policies are used as alternatives in the MDP.
Abstract: A multistage production/inventory system is modelled. The system structure, which has the form of an assembly network, is abstracted from the production process of a typical integrated iron and steel works. The system is modelled as a Markov Decision Process (MDP). Combinations of Just-In-Time (pull) and MRP (push) policies are used as alternatives in the MDP. Optimal hybrid strategies are developed. In part II, we extend our observations to a more general case.
TL;DR: In this article, the optimal cutter size selection and path generation for a pocket machining problem is considered. And the final part of the research deals with optimizing the cutter movement within this region.
Abstract: NC code generation, if done manually, forms the bottleneck in a production system. Hence automatic NC code generation forms an important part of a totally automated manufacturing system. Most of the existing systems for this task consider cutter path generation only for limited part geometry. The work proposed here considers both optimum cutter size selection and cutter path generation. The work done encompasses almost all the features found on prismatic parts, such as slots, steps, projections, etc. First the finishing and roughing tools are selected based on minimum cutter motion criterion, then algorithms for determining the area within the cutter centre can move are outlined. The final part of the research deals with optimizing the cutter movement within this region. So here we have developed the algorithms to select an appropriate cutter and also to generate the cutter path and NC code for machining a pocket using any given cutter.
TL;DR: A neural network system is used to generate part geometry-related digits of the Opitz code from bitmaps of part drawings and is found to generate codes accurately and promises to be a useful tool for the automatic generation of shape-based classes and codes.
Abstract: The classification and coding of parts for group technology applications continue to be labour intensive and time-consuming processes. In this paper a pattern recognition approach utilizing neural networks is presented for the automation of some elements of this critical activity. As an illustrative example, a neural network system is used to generate part geometry-related digits of the Opitz code from bitmaps of part drawings. It is found to generate codes accurately and promises to be a useful tool for the automatic generation of shape-based classes and codes.
TL;DR: In this paper, a methodology is presented based on linear programming formulation and which minimizes the service response time in an automated storage/retrieval system (AS/RS) through the optimal selection of the dwell point of the S/R machine when idle.
Abstract: A methodology is presented based on linear programming formulation and which minimizes the service response time in an automated storage/retrieval system (AS/RS) through the optimal selection of the dwell point of the storage/retrieval (S/R) machine when idle. Two separate models are developed; one model is based on the minimization of expected travel time while the other is based on the minimization of the maximum travel time between points. The procedure is very suitable for dynamic control of an AS/RS. The architecture for the automated implementation of the dwell point selection methodology in an actual industrial setting is also given. An example problem is presented to illustrate the application of the control techniques.
TL;DR: In this paper, the authors used an exact analytic model to conduct a detailed study of how machine breakdowns and interstage storage can significantly affect the efficiency of a production line and provided useful guidelines for designing or analysing production line systems.
Abstract: Both machine breakdowns and interstage storage can significantly affect the efficiency of a production line. In this paper we use an exact analytic model to conduct a detailed study of how these two factors affect the throughput of a line. Based on the empirical results, a simple heuristic method is given to estimate the amount of storage space required to offset the negative effect of machine breakdowns. The results provide useful guidelines for designing or analysing production line systems.
TL;DR: In this paper, a hierarchical approach to the continual plane facility layout problem is presented, which employs a divide-and-conquer strategy consisting of three phases: (1) cluster analysis, (2) initial layout, and (3) layout refinement.
Abstract: A hierarchical approach to the continual plane facility layout problem is presented in this paper. The approach employs a divide-and-conquer strategy which consists of three phases: (1) cluster analysis, (2) initial layout, and (3) layout refinement. Cluster analysis generates a hierarchical structure of the layout. Based on the structure, the second phase produces an initial layout of each cluster which is then refined by the layout refinement phase. The relatively small number of facilities in each cluster enables the problem formulation to embody more geometric constraints than existing methods. Cluster layouts are combined using a bottom-up merging process to generate the overall layout. The effectiveness of this procedure is demonstrated by experiments involving five to thirty facilities. Because of the hierarchical nature of this approach, it is suitable for plants with a large number of facilities which operate in tightly coupled groups
TL;DR: In this paper, a transient-based real-time scheduling algorithm which selects a dispatching rule dynamically for a next short time period in order to respond to changes of system state is proposed.
Abstract: Real-time scheduling in flexible manufacturing systems (FMS) is a difficult problem because of the complexities and dynamic behaviour of FMS. In this paper, a transient-based real-time scheduling algorithm which selects a dispatching rule dynamically for a next short time period in order to respond to changes of system state is proposed. In this algorithm, the scheduling interval associated with the selected dispatching rule is defined based on the system transient state as predicted by discrete event simulation. Simulation is also applied to evaluate the performance of the candidate dispatching rules for the next scheduling interval.
TL;DR: In this paper, the authors consider a production line consisting of several machines in tandem operating under a constant work in process (CONWIP) control strategy and develop an approximate regenerative model (ARM) for estimating throughput and average cycle time as a function of WIP level.
Abstract: We consider a production line consisting of several machines in tandem operating under a constant work in process (CONWIP) control strategy. We assume that processing times are deterministic but machines are subject to exponential failures and repairs. We model this system as a closed queueing network and develop an approximate regenerative model (ARM) for estimating throughput and average cycle time as a function of WIP level. We compare ARM with mean value analysis (MVA) and develop readily computable tests of the suitability of the two approaches to a given production system. Through comparison with simulations, we show that ARM gives better predictions than MVA in a range of realistic situations.
TL;DR: In this article, the authors examined the influence of scheduling and routeing flexibility on job shop flexible manufacturing systems within a static environment and explored the effects of interaction between scheduling and routing flexibility on performance.
Abstract: This research examines the influences that scheduling schemes and the degree of routeing flexibility have on random, job shop flexible manufacturing systems within a static environment. The first factor in the experiment includes three scheduling schemes. Two of these schemes are off-line schemes which schedule many operations prior to actual production. The first of the off-line schemes establishes an overall optimal solution, and the second off-line scheme decomposes the problem into a loading subproblem and a resulting scheduling subproblem and finds optimal solutions to both subproblems. The third scheme uses control policies and dispatching rules to establish a schedule in a real-time mode. The number of alternative machine options (i.e., the degree of routeing flexibility) is a second factor in the experiment and includes eleven levels. In addition, the effects of interaction between scheduling and routeing flexibility on performance are explored.
TL;DR: In this paper, a new model that includes two important factors which were not considered previously by the author has been developed and presented for determining optimal/near-optimal machine-part clusters in cellular manufacturing.
Abstract: A new model that includes two important factors which were not considered previously by the author has been developed and presented for determining optimal/near-optimal machine-part clusters in cellular manufacturing. First, the model takes into consideration the sequence of operations in evaluating the intercell and intracell moves; and second, it includes the impact of the layout of cells in evaluating the intercell moves. The total move is computed as a weighted sum of both intercell and intracell moves, and is used as a suitable measure to evaluate the performance of the model. Another measure incorporated in the model is the utilization of a workstation and a targeted minimum value of 50% utilization was used for each machine in a workstation. An efficient solution algorithm for this model was developed and implemented on a microcomputer. Its effectiveness was tested on different test problems that have appeared in the literature. Although the results presented cannot be compared directly wi...
TL;DR: This paper presents a new procedure that rebalances a given solution to level the allocation of tasks, and indicates that the procedure is very effective in levelling workloads.
Abstract: Most heuristic and optimal methods for assembly line balancing are designed either to minimize the number of workstations required given a production rate, or to maximize the production rate given a fixed number of workstations. This singular focus on line design efficiency typically results in an imbalanced allocation of tasks among the stations. This paper presents a new procedure that rebalances a given solution to level the allocation of tasks. Characteristics of dominant levelled solutions are identified and incorporated into this heuristic procedure. Computational results indicate that the procedure is very effective in levelling workloads.
TL;DR: In this paper, a planning model is developed to assist line managers in determining an optimal kanban policy at each workstation, and the model takes the form of a mixed integer linear program, and is solved with standard techniques.
Abstract: Significant reductions in setup and lead times reported by the Japanese have led Western manufacturers to rethink the need for complex computer-based MRP systems. Consequently, many of these firms have adopted some form of kanban for shop floor control. In this paper, a planning model is developed to assist line managers in determining an optimal kanban policy at each workstation. The objective is to work within the capacity of the system to balance cost and service over the planning horizon. The model takes the form of a mixed integer linear program, and is solved with standard techniques. When no shortages are permitted, a number of alternative formulations are introduced that sharply reduce the computational burden. Results are presented for an example based on the assembly of printed wire boards at Texas Instruments' Austin plant.
TL;DR: In this paper, the authors examine why the conventional job shop loading and fixed routeing concepts fail to capture the flexibility of flexible manufacturing systems and suggest ways to exploit the FMS flexibility.
Abstract: Research has found that while flexibility is purported to be a prime advantage of flexible manufacturing systems (FMS), it has not yet become a major competitive priority for American and European manufacturers. Moreover, many installed systems either are not very flexible or do not use the available flexibility to the best advantages. We suspect that inappropriate application of the conventional production management concepts to FMS is one of the major factors that hinders current FMSs from capturing their key advantage: flexibility. This paper takes a first step to examine why the conventional job shop loading and fixed routeing concepts fail to capture the flexibility of FMS. Once problems are identified we suggest ways to exploit the FMS flexibility. We further conduct an experiment to investigate FMS performance under different manufacturing policies and operating conditions. The results indicate that the performance of an FMS greatly diminishes when the conventional job shop loading and fix...