Showing papers in "Iie Transactions in 1980"
TL;DR: In this article, the basic features of flexible manufacturing systems are reviewed and models for determining the production capacity of such systems are developed, showing the desirability of a balanced work load, the benefit of diversity in job routing if there is adequate control of the release of jobs, and the superiority of common storage for the system over local storage at machines.
Abstract: The basic features of flexible manufacturing systems are reviewed and models for determining the production capacity of such systems are developed. These models show the desirability of a balanced work load, the benefit of diversity in job routing if there is adequate control of the release of jobs (a job shop can be better than a flow shop), and the superiority of common storage for the system over local storage at machines. The models are extended to allow for material handling delays between machines and for unreliable machines. It is also shown that production capacity models can be used to develop good approximations to the mean number of jobs in the system for given job arrival rates and machine utilizations.
278 citations
TL;DR: This paper presents simple methods for solving two single machine sequencing problems when job processing times are themselves decision variables having their own associated linearly varying costs.
Abstract: This paper presents simple methods for solving two single machine sequencing problems when job processing times are themselves decision variables having their own associated linearly varying costs. These are the problems of minimizing the total processing cost plus either the average flow cost or the maximum tardiness cost. The paper treats only problems with zero ready times and no precedence constraints.
220 citations
TL;DR: In this paper, two configurations of shelves, in a homogeneous or a zoned warehouse, are compared and expressions for optimal design parameters are developed from these, and some general preference rules for the two layouts examined can be laid down.
Abstract: Two configurations of shelves, in a homogeneous or a zoned warehouse, are compared. Handling costs as well as costs associated with the warehouse area and perimeter are taken into consideration. From these, expressions for optimal design parameters are developed. It is shown that, depending on ratios between the relevant costs, some general preference rules for the two layouts examined can be laid down.
131 citations
TL;DR: In this article, a heuristic decision rule is proposed based on the analysis of the one-product problem, and a new notion: the composite product, which is then tested by simulation on a series of problems, and is shown to be the most effective of the heuristics considered for the set of test problems.
Abstract: The multi-product production cycling problem is concerned with the determination of a production/inventory policy for a single capacitated production facility which is dedicated to producing a family of products. This paper studies this problem assuming stochastic demand. The one-product problem may be analyzed as a Markov decision problem and solved as such. For the multi-product problem, a heuristic decision rule is proposed based on the analysis of the one-product problem, and a new notion: the composite product. This heuristic is then tested by simulation on a series of problems, and is shown to be the most effective of the heuristics considered for the set of test problems
87 citations
TL;DR: This paper explores some of the typical problems in manufacturing systems planning and control, particularly those pertinent to the automatic operation, and describes how artificial intelligence methods can be applied.
Abstract: This paper explores some of the typical problems in manufacturing systems planning and control, particularly those pertinent to the automatic operation, and describes how artificial intelligence methods can be applied. We demonstrate how predicate logic and theorem proving techniques using resolution can be used in a manufacturing environment. Assertions of fact and axioms representing the knowledge required are given in an underlying data base. Illustrative problems demonstrate how user problems, such as assignment of jobs to machines when conflicts occur, can be handled by a decision support system in the framework of resolution in a problem reduction approach.
86 citations
TL;DR: In this paper, a single period mathematical model which allows marketing to choose prices and promotion strategies and allows production to choose production levels in an autonomous manner is presented, and an analysis of the effects of using incomplete information on the overall solution is given.
Abstract: This paper analyzes a single period mathematical model which allows marketing to choose prices and promotion strategies and allows production to choose production levels in an autonomous manner. The type and manner of information which must be known in order to find the joint optimum is presented, and an analysis of the effects of using incomplete information on the overall solution is given. An iterative scheme whereby production and marketing discover the correct information is presented.
81 citations
TL;DR: In this paper, a new concept of manufacturing operating system (MOS) is presented as an approach to decision support as well as actual control of automatic manufacturing and the E-Net technique is used to model the MOS environment including reference data, operational data, and decision logic.
Abstract: A new concept of Manufacturing Operating System (MOS) is presented as an approach to decision support as well as actual control of automatic manufacturing. The E-Net technique is used to model the MOS environment including reference data, operational data, and decision logic. Scheduling problems in a DNC line are illustrated.
76 citations
TL;DR: In this paper, the problem of placing a facility among n points so that the shortest weighted distance to a point is as large as possible is considered, where the facility must be within a pre-specified distance from each point; the facility is to be located on a plane and Euclidean distances are used.
Abstract: This paper deal with the problem where a facility must be placed among n points so that the shortest weighted distance to a point is as large as possible. At the same time the facility must be within a pre-specified distance from each point; the facility is to be located on a plane and Euclidean distances are used. Applications include the location of facilities that are obnoxious in the sense that they should be placed as far away from certain points as possible but still be within a pre-specified “reach” of these points.
69 citations
TL;DR: In this article, the comparative abilities and limitations of industrial robots and humans are reviewed, and a robot oriented job and skills analysis method is developed to optimize a robot's task-performance and guide the specification of the appropriate robot for given tasks.
Abstract: The comparative abilities and limitations of industrial robots and humans are reviewed. This comparison leads to the development of a robot oriented job and skills analysis method with a two-fold objective: 1) to optimize a robot's task-performance, and 2) to guide the specification of the appropriate robot for given tasks. An example of water pump assembly by a robot is used to illustrate the proposed method and its usefulness.
63 citations
TL;DR: An introduction to the identification, estimation, and diagnostic checking of discrete linear transfer functions to model the interrelationships between input and output time series.
Abstract: Time series analysis methods have been applied to a large number of practical problems, including modeling and forecasting economic time series and process and quality control. One aspect of time series analysis is the use of discrete linear transfer functions to model the interrelationships between input and output time series. This paper is an introduction to the identification, estimation, and diagnostic checking of these models. Some aspects of forecasting with transfer function models are also discussed. A survey of intervention analysis models in which the input series is an indicator variable corresponding to an isolated event thought to influence the output is also given. Familiarity with univariate autoregressive integrated moving average modeling is assumed. Extensions to more general multiple time series analysis methods are also briefly discussed.
56 citations
TL;DR: In this paper, an interactive graphical program is described for solving single-facility minimax location problems with nonconvex feasible regions, and the core of the program is a well-defined algorithm with a simple, human-executed pattern recognition task as one of its steps.
Abstract: This paper introduces interactive computer graphical optimization to location analysis. An interactive graphical program is described for solving single-facility minimax location problems with nonconvex feasible regions. The core of the program is a well-defined algorithm with a simple, human-executed pattern recognition task as one of its steps. Globally optimal solutions are assured under very mild assumptions on human performance, and the program is reasonably fast.
TL;DR: In this paper, the results of a survey taken among members of the Operations Research Division of the American Institute of Industrial Engineers as to perceived utility and familiarity with twelve methodologies commonly used in industrial engineering practice are presented.
Abstract: This study presents the results of a survey taken among members of the Operations Research Division of the American Institute of Industrial Engineers as to perceived utility and familiarity with twelve methodologies commonly used in Industrial Engineering practice. A modification to the method of majority rule for weighting the opinions of respondents, based upon their degree of familiarity or expertise, is also presented.
TL;DR: This study investigates the influence of three groups of variables on the chosen model: working conditions, type of instructions, and previous experience and shows that the predictability power of the model is a function of operational variables as well as the specific model which is applied.
Abstract: The learning curve is one of the tools in operation planning and control. It enables the planner to estimate the future performance of tasks executed either by individuals or organizations. Choosing the appropriate mathematical model that depicts learning is usually based on a “least square oriented” searching procedure, hence prior knowledge of the possible model that may fit a certain operation would facilitate the searching procedure. This study investigates the influence of three groups of variables on the chosen model: working conditions, type of instructions, and previous experience. The following three models were investigated: linear, power, and exponential. Results show that the predictability power of the model is a function of operational variables as well as the specific model which is applied.
TL;DR: In this paper, a real life case study of the design and implementation of a production planning system in an aluminium rolling mill is presented, where a tailor-made computerized production planning was set up for this company, and a specific dispatching algorithm was developed taking into account due dates of individual orders, production targets on finishing machines, and external factors.
Abstract: A real life case study of the design and implementation of a production planning system in an aluminium rolling mill is presented. A tailor-made computerized production planning system was set up for this company. On the aggregate level, a package was developed for simulating future machine loads. These simulations yield all necessary information for determining a production make span for each individual family of products so as to optimize overall machine capacity utilization. 0n the day to day operational level, another package was developed in order to determine the manufacturing schedule of specific orders on a daily basis. A specific dispatching algorithm was developed taking into account due dates of individual orders, production targets on finishing machines, and external factors. This article includes a description of the system and some comments on the actual implementation and possible future extensions.
TL;DR: In this paper, the problem of finding a minimum makespan permutation schedule in a deterministic flow-shop without intermediate queues is equivalent to the shortest distance routing traveling salesman problem, and an algorithm, having quadratic worstcase complexity in terms of the number of partial schedules explicitly enumerated, has been presented.
Abstract: The problem of finding a minimum makespan permutation schedule in a deterministic flow-shop without intermediate queues is equivalent to the shortest distance routing traveling salesman problem. If the task system is semi-ordered, the associated distance matrix of the corresponding traveling salesman problem is found to exhibit some peculiar characteristics. Consequently, we are able to derive some important results which help us to eliminate permutations in the search of the minimum makespan permutation schedule. The most important result is that the optimal permutation schedule is pyramidal. An algorithm, having quadratic worst-case complexity in terms of the number of partial schedules explicitly enumerated, has been presented. Some particular cases of the semi-ordered flow-shop are also discussed.
TL;DR: A general formula for the production capacity of automatic transfer lines where partially processed units may have to be scrapped when the machine fails is derived.
Abstract: In this paper we derive a general formula for the production capacity of automatic transfer lines where partially processed units may have to be scrapped when the machine fails. In the derivation of this formula it is assumed that the buffer spaces between adjacent work stations are unlimited.
TL;DR: In this article, a mixed integer programming model is developed for studying the problem of centralized blending plants that could take coals of varying sulfur content and produce a coal product that would meet the coal consumers needs based upon effluent standards.
Abstract: In order to meet increasingly stringent environmental standards, coal burned by utilities and industries must be of an acceptable lower sulfur content. One solution suggested in this paper is the establishment of centralized blending plants that could take coals of varying sulfur content and produce a coal product that would meet the coal consumers needs based upon effluent standards. A mixed integer programming model is developed for studying this problem. A case study is presented with coal data for the State of Indiana. Model results on the number of blending plants to be selected, their site locations, optimal blending ratios, transportation configuration, and cost savings are discussed.
TL;DR: This work proposes an iterative heuristic procedure based on the observation that a two-machine makespan problem is trivially reduced to a Knapsack problem and capitalize on the very special structure of the ILP to effect the reduction with small multipliers.
Abstract: In this paper we study the problem of scheduling n independent jobs available at time zero on m ≥ 2 parallel and identical processors with the objective of minimizing the makespanJWe propose two approaches, both are Knapsack-based. The first is analytical and depends on reducing the set of m occupancy constraints to a single Diophantine equation. We capitalize on the very special structure of the ILP to effect the reduction with small multipliers. The second approach is an iterative heuristic procedure that is based on the observation that a two-machine makespan problem is trivially reduced to a Knapsack problem. Computational experience indicates the superiority of this approach over other existing approaches. Realistic problems of up to 100 jobs on 10 machines are solved in a few seconds on the IBM 370/165.
TL;DR: In this paper, various methods of selecting observation times in work sampling studies are presented, including simple random, systematic, and stratified sampling, and a new method called restricted random sampling.
Abstract: Various methods of selecting observation times in work sampling studies are presented, including simple random, systematic, and stratified sampling, and a new method called restricted random sampling. The attributes of these sampling methods are evaluated, particularly statistical efficiency, and the important advantages of stratification are demonstrated. Finally, the analysis of variance is recommended for statistical analysis of work sampling data to account for the presence of several sources of variation, in addition to sampling error.
TL;DR: In this paper, a solution procedure is presented for the single decision variable (machine speed) case, and an example problem is also presented to illustrate the gains that can be attained using lot size information.
Abstract: The research literature on metal cutting contains numerous papers on optimizing machining parameters for maximum production rate or minimum production cost. Analyses presented in the literature, however, have been limited to conditions of “steady-state” manufacture (i.e., a large number of parts were to be produced). In today's metal cutting industry, over ninety percent of all parts are produced in lots of thirty or less. This implies that steady-state manufacturing may never be reached. This paper introduces lot size information into the selection of machine operating rates. A solution procedure is presented for the single decision variable (machine speed) case. An example problem is also presented to illustrate the gains that can be attained using lot size information.
TL;DR: In this paper, expressions for the distribution and expected value of uptime for systems subject to both repairable and nonrepairable failures are derived for a wide range of situations, including the analysis of systems that are subject to major structural failure, product or process obsolescence, or failure of critical non-repairable subsystems.
Abstract: Expressions are derived for the distribution and expected value of uptime for systems subject to both repairable and nonrepairable failures. The results are applicable to a wide range of situations, including the analysis of systems subject to major structural failure, product or process obsolescence, or failure of critical nonrepairable subsystems. Several examples are investigated, including multiple component series systems, systems containing standby redundant nonrepairable subsystems and systems containing standby redundant repairable subsystems.
TL;DR: In this article, the authors used classical optimization techniques to develop optimal strategies for a single production line with semifixed operating costs and linear variable costs, which can be used to match production to demand when demand is less than plant capacity.
Abstract: Many plants have a semifixed operating cost which can be saved when the plant is shutdown. When demand is less than plant capacity production must be reduced to prevent inventory accumulation. Production strategies for matching production to demand are: (1) throttling the production to equal demand or, (2) producing at capacity rates and periodically shutting down to reduce inventories. This paper uses classical optimization techniques to develop optimal strategies for a single production line with semifixed operating costs and linear variable costs.
TL;DR: Q-GERT as mentioned in this paper is a derivative of GERT network modeling and includes such features as probabilistic branching, network looping, multiple node realizations, and queue nodes which make it applicable to complex network forms such as production flow lines.
Abstract: Numerous techniques and algorithms have been developed for the analysis of production flow line systems. However, due to the complex nature of such systems, it is often possible to analyze only a small segment of the production line system at one time. When solution designs result from this analysis and are then implemented within the overall system, inefficient results can and frequently do occur. As such, an overall methodology is needed to analyze complex production line systems in their entirety. Q-GERT network modeling and simulation offers unique possibilities for this purpose. Q-GERT, a derivative of GERT network modeling, includes such features as probabilistic branching, network looping, multiple node realizations, and queue nodes which make it applicable to complex network forms such as production flow lines. In this paper Q-GERT is demonstrated as an appropriate vehicle for analysis via a detailed case example of a multi-product, multi-line production system. The production system is f...
TL;DR: In this paper, a general method for determining the minimum number of independently distributed random variables needed in a linear combination to allow the distribution of the linear combinations to be adequately approximated by the normal distribution is developed.
Abstract: A general method for determining the minimum number of independently distributed random variables needed in a linear combination to allow the distribution of the linear combination to be adequately approximated by the normal distribution is developed. The method is based on the convergence of linear combination third and fourth moments to their respective normal distribution equivalents.
TL;DR: In this paper, a mathematical model is developed for the case where one class of customers can preempt the other and the mean service times of each class of customer may be different, which is then used to numerically investigate the behavior of various measures of performance as well as the system in general.
Abstract: This paper considers the following queueing system:; two classes of customers use the same s-server loss system. A mathematical model is developed for the case where one class of customer can preempt the other and the mean service times of each class of customer may be different. These results are then used to numerically investigate the behavior of various measures of performance as well as the system in general.
TL;DR: In this paper, an ad hoc method is presented which consists of decomposing the original series into two series, one consisting only of non-zero values, while the other is modeled as a Markov chain with states zero and one.
Abstract: When forecasting the demand for a product, it is sometimes necessary to model time series which are a mixture of zeros (i.e., no demand) and values much larger than zero. An ad hoc method is presented which consists of decomposing the original series into two series, one of which consists only of non-zero values, while the other is modeled as a Markov chain with states zero and one. The non-zero values are modeled as an ARIMA process. The Markov chain is classified using a statistical method due to Tong. These two series can then be used to generate an ensemble of forecasts for a given lead time, each with a specified probability of occurrence. Two illustrations of the method are made to series which represent market demand for steel.
TL;DR: An approach to the study of inspection task design has been investigated 20 female inspectors did a simulated paced visual inspection task for 90 minutes each The experimental variables were display size, product pacing, and fault information as a measure of defect probability as discussed by the authors.
Abstract: An approach to the study of inspection task design has been investigated Twenty female inspectors did a simulated paced visual inspection task for 90 minutes each The experimental variables were display size, product pacing, and fault information as a measure of defect probability They were tested in a 15 point design with 3 replications of the center point The criterion of performance was the fraction of total products correctly identified as being defect free From the experimental data quantitative estimates of performance increments or decrements associated with changes in inspection task variables were determined The implications of observations and their importance in the design of an inspection task have been discussed
TL;DR: This tutorial article, a basic introduction to number systems, binary arithmetic, and binary logic topics is provided, dealing with concepts and techniques for interfacing microcomputers to industrial devices.
Abstract: In order to effectively plan and develop projects involving microcomputers, the industrial engineer requires background information on number systems, binary arithmetic, and binary logic. In this tutorial article, a basic introduction to these topics is provided. Specific topics include: positional number systems, conversion between number systems, addition and subtraction of binary numbers, the two's complement of negative numbers, the ASCII and Gray codes, the basic logic functions (AND, OR, NOT, NAND, NOR, XOR), and some applications of basic logic functions, including a decoder, an adder, and a binary latch. This is the first of an integrated series of articles dealing with concepts and techniques for interfacing microcomputers to industrial devices.
TL;DR: In this article, the problem of sampling from a finite population defined on the interval (1, 2, …, T), using a restricted form of random sampling in which the spacing between consecutive observations must be at least some minimum value, M, was considered.
Abstract: This paper considers the problem of sampling from a finite population defined on the interval (1, 2, …, T), using a restricted form of random sampling in which the spacing between consecutive observations must be at least some minimum value, M. For this type of restricted random sample, of size N, the value M can be arbitrarily specified in the range from zero, corresponding to simple random sampling with replacement, to a maximum of T/N, corresponding to systematic sampling. An efficient procedure is developed for generating a sample for specified values of N, M and T. It is then shown, by computer simulation, that values of M in the range from 60 to 90 percent of T/N retain most of the advantages of systematic sampling, while avoiding most of the disadvantages for some special processes., Also, the error variance associated with stratified sampling is comparable to restricted random sampling with a minimum spacing of about 70 percent, and both methods are almost as efficient as systematic sampling.
TL;DR: It is shown that the algorithm presented yields good estimates of the utilizations in the two stage cyclic queue model used to model snow removal operations, computer systems, earthmoving operations, etc.
Abstract: The two stage cyclic queue model with general service time distributions of the Erlang class and with time lags between facilities can be used to model snow removal operations, computer systems, earthmoving operations, etc. The utilization of each facility is computed by an heuristic approach (which is explained in some detail). Tables of utilizations are generated for a special subset of these models and an algorithm to compute utilizations for any general case from these tables is then developed. It is shown that the algorithm presented yields good estimates of the utilizations.