Showing papers in "International Journal of Production Research in 1977"
TL;DR: The Toyota Production System and Kanban System introduced in this paper was developed by the Vice-President of Toyota Motor Company, Taiiohi Ohno, and it was under his guidance that these unique production systems have become deeply rooted in Toyota Motor company in the past 20 years as mentioned in this paper.
Abstract: SUMMARY The Toyota Production System and Kanban System introduced in this paper was developed by the Vice-President of Toyota Motor Company, Mr. Taiiohi Ohno, and it was under his guidance that these unique production systems have become deeply rooted in Toyota Motor Company in the past 20 years. There are two major distinctive features in these systems. One of these is the ‘just-in-time production ’, a specially important factor in an assembly industry such as automotive manufacturing. In this type of production, “ only the necessary products, at the necessary time, in necessary quantity ” are manufactured, and in addition, the stock on hand is held down to a minimum. Second, the System is the ‘respect-for-human’ system where the workers are allowed to display in full their capabilities through active participation in running and improving their own workshops.
1,266 citations
TL;DR: In this article, the method given in this paper is typically applicable to those inventory problems where a product is procured by a single customer from a single supplier and an example has been solved to illustrate the method.
Abstract: SUMMARY The method given in this paper is typically applicable to those inventory problems where a product is procured by a single customer from a single supplier. An example has been solved to illustrate the method.
917 citations
TL;DR: A procedure that classifies set-up operations and predicts the set- up times is developed and a method for sequencing the jobs so as to minimize the total set-ups time is developed.
Abstract: On many machine tools the set-up times are sequence dependent; that is, the time to set-up for the new part is dependent upon the part for -which the machine is currently set-up. In scheduling lots on the machine, the set-up time is often a significant component of the total time required to complete each lot. Set-up times are frequently not available to the production scheduler, and when they are, they frequently are only averages which conceal the sequence dependency of the set-up times. In this paper, we first develop a procedure that classifies set-up operations and predicts the set-up times and we then develop a method for sequencing the jobs so as to minimize the total set-up time. An example using real world data is used to illustrate these procedures
64 citations
TL;DR: The basic analytical approaches to the machine requirements problem are discussed, and the problem's classification scheme is presented to categorize alternative approaches which might be used to formulate and analyse the problem.
Abstract: The purpose of this paper is to provide an overview of the machine requirements problem. The problem is described and a classification scheme is presented to categorize alternative approaches which might be used to formulate and analyse the problem. In addition, this article discusses the basic analytical approaches to the problem which have been reported in the literature, and relates these approaches to the problem's classification scheme. Conclusions are drawn us to strengths and weaknesses of the approaches, as well as to potential research directions
38 citations
TL;DR: This paper considers the properties of the interstage buffer storage capacity as a ‘ decoupling agent ’ in multi-station non-powered assembly lines, where the economics of production are achieved by balancing delay costs against stock-carrying costs and storage space costs.
Abstract: This paper considers the properties of the interstage buffer storage capacity as a ‘ decoupling agent ’ in multi-station non-powered assembly lines, where the economics of production are achieved by balancing delay costs against stock-carrying costs and storage space costs. A simplified mathematical model for exponential service time distribution based on the ‘ cyclic queue ’ concept has been developed, taking into account the three cost parameters, to optimize the buffer storage capacity. A numerical example and sensitivity analysis of the model are presented.
30 citations
TL;DR: Results for six industrial operators performing light assembly tasks confirm the optimum time delay prediction as judged by the minimization of mean square error criterion, and the frequency response analysis is confirmed on application to a learning curve describing crew performance during a simulated naval underwater mission.
Abstract: SUMMARY The paper investigates the effect of exponentially smoothing learning curve data plotted in the time constant model form. In the time domain, the result is a smoothed, delayed version, of the raw data. Attenuation of scatter about the trend line is predicted using the z transform method to establish the exponential smoother frequency response. The optimum time shift for trend correction is determined by an analogue method based on the Matsuburu time delay theorem, the result being identical to that obtained using the ‘ equivalent age of data ’ concept. Results for six industrial operators performing light assembly tasks confirm the optimum time delay prediction as judged by the minimization of mean square error criterion, and the frequency response analysis is confirmed on application to a learning curve describing crew performance during a simulated naval underwater mission.
29 citations
TL;DR: In this paper, the effects of total work-in-process inventory capacity, relative inter-station inventory allocations and pattern of processing time variances upon production rate, work station idle times and time to complete a product were analyzed.
Abstract: This paper demonstrates problems in allocating inter-station inventory capacities in unpaced production lines with heteroscedastic processing times. Simulations were performed to show the effects of total work-in-process inventory capacity, relative inter-station inventory allocations and pattern of processing time variances upon production rate, work station idle times and time to complete a product. Trade offs among the three performance measures were observed and deficiencies in intuitive strategies for redesigning lines were deduced.
28 citations
TL;DR: In this paper, a probabilistic periodic review model has been developed for an inventory system with deteriorating items, and an expression has been derived for the optimum lot-size for any general rate of deterioration.
Abstract: A probabilistic periodic review model has been developed for an inventory system with deteriorating items. The model is derived for any general rate of deterioration. As particular cases, both the constant and varying rate of deterioration are considered. An expression has been derived for the optimum lot-size. An example is given to show the solution form
22 citations
TL;DR: In this article, a tool-life predicting equation with four variables of speed, feed, depth of cut and direct current was developed and a good correlation between the predicted and actual tool life test results was obtained.
Abstract: SUMMARY Response surface methodology had been applied to tool-life study in conventional machining. This paper presents results of the application of this statistical technique to direct current hot machining. A tool-life predicting equation with four variables of speed, feed, depth of cut and direct current was developed. Good correlation between the predicted and actual tool-life test results was obtained.
20 citations
TL;DR: In this paper, a production model with variable (speed-dependent) production time and cost for producing a product item was constructed, and an optimization analysis was performed on a single-item, multistage production system in an attempt to determine the optimal production speeds for all stages and the optimal cycle time.
Abstract: SUMMARY Introducing a concept of ‘ production speed ’ as a decision variable, a production model with variable (speed-dependent) production time and cost for producing a product item was constructed. Optimization analysis was mode on a single-item, multistage production system in an attempt to determine the optimal production speeds for all stages and the optimal cycle time. For a case of multiple-item production, an optimal job sequence and the optimal production speeds for all jobs were analysed, such that the total flow time was minimized as a primary objective and, in addition, the total production cost was minimized as a secondary objective.
20 citations
TL;DR: In this article, a mathematical model is proposed for explaining the relationship between tool wear and temperature, which is supported by good statistical agreement between the data and the form of the proposed equation.
Abstract: Experimental data are presented which demonstrate a strong correlation between tool wear and the signal of a thermocouple located at a position on the cutting tool remote from the cutting edge. A mathematical model is proposed for explaining this relationship between tool wear and- temperature. The model is supported by good statistical agreement between the data and the form of the proposed equation. For a total of nine different machining conditions with replications for several of the conditions, the correlation coefficient ranged in value between 0·837 and 0·978.
TL;DR: The results indicated that the unpaced work imposed a higher load upon the subject than the paced work, and the organism seems to be ‘driven’ by the machine under paced conditions, and works with a kind of momentary ‘physiological lag’.
Abstract: SUMMARY Trained subjects performed a simple assembly task under self-paced and machine-paced working conditions. Work cycle times, respiratory intervals and cardiac R—R intervals were recorded continuously throughout 2 hours of unpaced and 2 hours of paced work of the same rate as the subject's mean unpaced performance. The two kinds of work were shown to be physiologically different, not in the direction physiological changes, but in their general levels and rates of change. The results indicated that the unpaced work imposed a higher load upon the subject than the paced work. It is also indicated that the organism may be prepared in advance for the work under unpaced conditions, while it seems to be ‘driven’ by the machine under paced conditions, and works with a kind of momentary ‘physiological lag’.
TL;DR: In this paper, the authors developed an integrated production scheduling system centring around the scheduling simulator and designed a scheduling simulator capable of policy selection, and thereby successfully developed a system under study simple and usable in practical applications.
Abstract: SUMMARY The primary purpose of production scheduling at an integrated iron and steel works is to establish and execute the optimum production schedule that can improve both productivity and yield at each of the plants such as the steelmaking plants and rolling mills, while giving first consideration to the keeping of the date of delivery However, it is by no means a simple matter to establish and control an integrated or consistent production, schedule covering about ten production processes for various products with an annual output of 6 million tons or more, or about 26 000 orders monthly In our system-development efforts, therefore, we made the system under study simple and usable in practical applications, designed a scheduling simulator capable of policy selection, and thereby successfully developed an integrated production scheduling system centring around the scheduling simulator.
TL;DR: In this article, the authors investigated the extent to which errors in estimation affect the optimality of the control procedure and found that four parameters are found to have negligible effect, three to have moderate effect, and two to have critical effect.
Abstract: SUMMARY In a previous paper the author has studied some properties of the minimum cost control schemes using np-charts. The process model involves nine independent data parameters whose values have to be estimated before an optimum np-chart can be determined. Since errors in estimation often occur in practice, the present paper investigates the extent to which these errors affect the optimality of the control procedure. Four parameters are found to have negligible effect, three to have moderate effect, and two to have critical effect. Rased on these results, a discussion is presented on the practicality of the economic approach.
TL;DR: In this article, a mathematical model was developed for the three channel ordered entry conveyor system with two types of arrivals having independent Poisson distribution, and the steady state probabilities and the system's measures of performance for the following cases: (1) the unserviced units are considered lost to the system allowing either homogeneous or heterogeneous servers at the service channels.
Abstract: SUMMARY The basic objective of this paper is to investigate the ordered entry conveyor serviced production system with dual input, and to analyse the probabilistic nature of such a system through the application of queueing theory. A mathematical model was developed for the three channel ordered entry conveyor system with two types of arrivals having independent Poisson distribution. The paper develops the steady-state probabilities and the system's measures of performance for the following cases: (1)The unserviced units areconsidered ‘lost’ to the system allowing either homogeneous or heterogeneous servers at the service channels. (2)The unserviced units are allowed to recirculate and enter the system as a new arrival. For each case, the steady-state probabilities and the system's measures of performance are evaluated.
TL;DR: To obtain an approximate solution for a large-scale job-shop scheduling problem the decomposition method was investigated, which means that an original problem is decomposed into subproblems, which are solved separately, and then the solution of the originalproblem is composed from the subpro problems' solutions.
Abstract: SUMMARY To obtain an approximate solution for a large-scale job-shop scheduling problem the decomposition method was investigated. This means that an original problem is decomposed into subproblems, which are solved separately, and then the solution of the original problem is composed from the subproblems' solutions. Different methods to decompose the problem were tested by computational experiments and evaluated from the viewpoint of the goodness of schedule and computation time.
TL;DR: In this article, the steady-state behavior of two and three channel conveyors is investigated, and two queue disciplines are considered, ordered entry (OE) and service in random order (SIRO).
Abstract: This paper investigates the steady-state behaviour of two and three channel conveyors. There are N types of arrivals, each type is governed by an independent Poisson distribution. Two types of queue disciplines were considered, ordered entry (OE), and service in random order (SIRO). The system's measures of performance were developed.
TL;DR: A survey of the literature available on the management of production inventories can be found in this paper, where both material requirements planning (MRP) and statistical inventory control (SIC) techniques are compared.
Abstract: SUMMARY The problem of inventory control has received increasing attention over the last 16 to 20 years, which has resulted in a vast amount of literature. Two types of inventory can be distinguished: (1) manufacturing inventories, which contain dependent demand items and are most efficiently controlled by means of Material Requirements Planning (MRP), and (2) distribution inventories, which contain independent demand items and for which Statistical Inventory Control (SIC) techniques are usually employed. This paper is a survey of the literature available on the management of production inventories. It deals with, and compares, MRP and SIC as both these techniques are used in industry. For literature published before 1972 this survey has been based mainly on review articles, but for the period of 1972 to 1976 original books and papers are reviewed and listed as references.
TL;DR: In this article, the critical nicker fusion test (CFF), performance test (rejection rate of defective bottles) and observation of subsidiary behaviour (looking around, napping, chattering, etc.).
Abstract: SUMMARY Several investigations have been made in soft drink plants during the past 2 years (1970-71) by carrying out the critical nicker fusion test (CFF), performance test (rejection rate of defective bottles) and observation of subsidiary behaviour (looking around, napping, chattering, etc.). Subsidiary behaviour appears to be a compensatory motion, the occurrence of which was related to a low level of worker's consciousness in the monotonous work. Subsidiary behaviour is considered an escape behaviour from monotony and is required as a stimulus which may relieve the feeling of monotony. The monotonous work was confirmed in close observation of the subsidiary behaviours.
TL;DR: A fuzzified bayes formula for decision-making is proposed, and the fuzzy observation system is discussed in order to make clear some properties of the fuzzy information.
Abstract: SUMMARY In some systems where human aspects have to be included, such as management systems, the problems of decision-making in a fuzzy environment have recently attracted special interest in a sense that it is becoming incre:isingly clear that many real-world problems have more to do with fuzziness, rather than randomness, for the major source of imprecision In this paper, a fuzzified bayes formula for decision-making is proposed, and the fuzzy observation system is discussed in order to make clear some properties of the fuzzy information. On the basis of the above discussion, a global decision approach is proposed.
TL;DR: In this paper, an adaptive control algorithm is formulated which provides, in real time, an optimal adjustment to a controller Bet-point in response to changes in the operating characteristics of the process.
Abstract: SUMMARY An adaptive control algorithm is formulated which provides, in real time, an optimal adjustment to a controller Bet-point in response to changes in the operating characteristics of the process. Such an algorithm is applicable to a variety of industrial processes: for example, those in which the product is either a containerized consumable or a sheet of some type. A Bayesian model is developed for the univariate case and the optimal control policy found. Multivariate extensions are also considered, as is the problem of process overhaul.
TL;DR: In this article, the authors presented an analysis of tool-wear data mainly from the view-point of flank wear, and a theory was presented on the prediction of volume of tool wear.
Abstract: SUMMARY This paper presents an analysis of tool-wear data mainly from the view-point of flank wear. Mechanism of wear of cemented carbide tools is considered to be of two main types: (i) mechanical interaction, with adhesion-transfer type being the main cause and mechanical abrasion of secondary importance; (ii) thermochemical type, which is considered to be a diffusion process closely associated with temperature. A theory is presented on the prediction of volume of tool wear, and experimental results are presented and compared with theory.
TL;DR: In this article, the relations between the number of set-ups, the lead-time, the total elapsed time, the in-process waiting time and the tardiness time on two-stage multi-item models were analyzed.
Abstract: SUMMARY A lot production system is, generally, adopted in the fabrication shop, which supplies the components for the following assembly line In such a shop, it is required to supply the components for the following assembly lino without tardiness and to reduce the in-process inventory In this paper, we analyse the relations between the number of set-ups, the lead time, the total elapsed time, the in-process waiting time and the tardiness time on two-stage multi-item models, and propose a procedure to determine the number of set-ups and the lead time
TL;DR: This paper quantitatively combines economics and error and clearly illustrates the adverse monetary effects of imperfect measurement in situations where variables acceptance sampling is used.
Abstract: Considerable attention to the economics of variables acceptance sampling has recently emphasized that the alpha-beta approach to sampling plan design may be far from optimal. Similarly, recent results conclusively show that measurement error manifested as bias (inaccuracy) and imprecision (variability) can have disastrous effects upon the OC curve of a variables sampling plan. This paper quantitatively combines economics and error and clearly illustrates the adverse monetary effects of imperfect measurement in situations where variables acceptance sampling is used
TL;DR: Propositions for autonomous decision-making by the task performer under various conditions, derived from the model, were confirmed through extensive investigations of actual workstations.
Abstract: This paper describes a model for task related decision-making. A distinction is made between three types of task decisions: boundary control decisions, which related the task system to its environment; intrasystem control decisions, which determine the means of performing the assigned tasks; and regulation decisions, which counteract disturbances that may affect task performance. Propositions for autonomous decision-making by the task performer under various conditions, derived from the model, were confirmed through extensive investigations of actual workstations. Implications of research findings on job design are also discussed.
TL;DR: In this paper, an adaptive control system is proposed in which a given amount of tool wear is allowed per operation and the objective is to machine a certain feed distance in the minimum tune using no more than the wear allowed and working within the conventional adaptive control constraints.
Abstract: SUMMARY An adaptive control system is proposed in which a given amount of tool wear is allowed per operation. The objective of the control system is to machine a certain feed distance in the minimum tune using no more than the wear allowed and working within the conventional adaptive control constraints. The average rate at which the operation progresses can thus be regulated by appropriately setting the wear target. The adaptive control system has been applied to the control of a lathe performing a simple bar turning operation. An on-line computer receives transducer responses, calculates and issues feed and speed corrections. The optimization policy requires the tool wear rate to be estimated while cutting and in this work the estimation was made from the cutting process variables including the tool-work thermocouple voltage. Workpiece disturbances in the form of hardness changes were introduced and the experimental responses of the control system to these disturbances are presented. The success of esti...
TL;DR: A production control plan is described which may be used in a shop whose product line consists of numerous items which vary extensively in their demand pattern, and which is capable of stabilizing production by allowing inventories to fluctuate with moderate demand fluctuations.
Abstract: SUMMARY This paper describes a production control plan which may be -used in a shop whose product line consists of numerous items which vary extensively in their demand pattern. The plan is capable of: (a) stabilizing production by allowing inventories to fluctuate with moderate demand fluctuations; (b) minimizing inventories of finished goods while providing protection against serious Btockout; (c) detecting significant changes in demand patterns and revising production schedules accordingly; and (d) scheduling production economically. Employing several well-known concepts, such as the control limits principle used in quality control, the plan considers simultaneously forecasted demand, forecast error, inventory position and shop capacity to arrive at production decisions. For this purpose, control limits are applied to both demand and inventory, and production is stabilized with a simple production smoothing procedure. Simulation results, based on data taken from a medium size production shop, demonstra...
TL;DR: In this article, a case study of forecasting daily traffic levels at branch banks, where many behavioral and business factors are present, is presented, where a univariate time series ARIMA model is developed mid then dummy variables are added to incorporate exogenous effects that are not captured by the projection ARIMa model.
Abstract: This paper illustrates a case study of forecasting daily traffic levels at branch banks, where many behavioural and business factors are present. Many influences are not equally spaced over, which reduces the effectiveness of traditional time series approaches. To handle this problem, a univariate time series ARIMA model is developed mid then dummy variables are added to incorporate exogenous effects that are not captured by the projection ARIMA model. The results indicate that a more adequate representation of the customer traffic pattern has been obtained by combining the two modelling approaches
TL;DR: In this paper, the experimental results have been used to derive an empirical model, interrelating the mechanical properties of the sheet with different variables selected in order of their effects on the particular mechnaical property.
Abstract: SUMMARY In laboratory experiments on the rapid partial annealing of cold-worked mild steel sheet, the experimental results have been used to derive an empirical model, interrelating the mechanical properties of the sheet with different variables selected in order of their effects on the particular mechnaical property. The validity of these process model relationships was tested by predicting the mechanical properties coreesponding to each of the experimental conditions included in the model and comparing them with the actual experimental values. This comparison revealed that only the 0-2% P.S. and the T.S. equations satisfactorily predict properties to an acceptable degree of accuracy. The scope and limitation of this type of empirical model are discussed in terms of application and the difficulties associated with precisely defining the pertinent process or material variables. Finally, it is demonstrated how the equations can be used to optimize the different process variables to achieve a given property...
TL;DR: The writing and development of decision tables for implementation in a manufacturing system is indicated here giving details of appropriate checking procedures and con straint boundaries.
Abstract: SUMMARY Decision tables provide a graphical representation of complex procedures in a way that is easy to visualize and understand. The work required to define the system, develop and programme the solution and to provide the often neglected documentation can be incorporated in a tabular form so that all elements of decision taking are precisely denned. The tables present the relationships among the interfacing variables dearly and show the necessary sequences of conditions and actions in a simple manner. The writing and development of decision tables for implementation in a manufacturing system is indicated here giving details of appropriate checking procedures and con straint boundaries.