Rintaro Muramatsu

Integrated production, inventory and distribution systems

This paper deals with the problem of how to determine, with high reliability, economic levels for the base stock and lead times for production and transportation in integrated production, inventory and distribution systems (IPIDS). This system model has a ‘pull type’ ordering system and is of the three stage tandem type, consisting of manufacturer, wholesaler and retailer. A method is described for fixing ‘base stock’ levels and lead times, when product production and transportation stop, which prevents out of stock and minimizes dead stock at each stock point in the case where product models are changing in the market.

Analysis of production ordering quantities and inventory variations in a multi-stage production ordering system

In the Japanese automobile and electrical industries it is often necessary to consider the production ordering systems as multi-stage production inventory systems. Previous analyses of production ordering systems have left untouched the variations in the production ordering quantities and inventory at each stage, in spite of the fact that the amplification phenomena of these variations are critical in a multi-stage production inventory system. Generally, we are able to classify the multi-stage production ordering systems into two types, i.e. the push-type and the pull-type. This paper discusses the following subjects concerning the push-type and multi-stage production ordering system based on forecasting: (1) the effects of demand fluctuations and forecast errors on the amplification of production order variations and inventory variations in terms of a basic production ordering model, and (2) the same effects in a modified production ordering model which is able to decrease both the variations in the prod...

A Successful Application of Job Enlargement/Enrichment at Toyota

Abstract When designing a production system to meet the company desires, the desire of the workers should also be considered. A survey at the Toyota Tsutsumi plant indicated that workers wanted enlarged/enriched jobs. The jobs were enlarged/enriched through a system of cross-training and job rotation. Productivity and quality were improved.

Feedback method of production ordering system in multi-stage production and inventory systems

Abstract This paper deals with the problem of developing a production ordering system which maintains high reliability and productivity of multi-stage production and inventory systems with capacity-constraint and machine breakdown. In this paper, two ‘push type’ production ordering systems (Matsuura and Soshiroda 1981) are proposed according to information feedback methods. The influence of forecasting error, the difference between forecasted demands, down-time, and the backlog caused by the restriction of production capacity, upon the production and inventory levels is analysed by each production ordering system. The results indicate that, in designing an effective production ordering system, a feedback method must be chosen according to the conditions of the average loading ratio, the down-time, and the autocorrelation coefficient of demand.

LOW-INVENTORY ORDERING SYSTEMS FOR THE INTERNATIONAL CO-OPERATIVE KNOCKDOWN PRODUCTION SYSTEMS

SUMMARY This paper aims to clarify the properties of the ordering systems of the international co-operative knockdown production systems (ICKDPS) for mutual countrys development. The ICKDPS consists of a three-stage production, inventory and transportation system. Two types of ordering models based on the pull-type ordering system are formulated, and the relations between the transportation lead time and variations of ordering quantity and inventory quantity are analysed in an attempt to improve the productivity and reliability of the ICKDPS.

Designing a pull-type parts procurement system for international co-operative knockdown production systems

In this paper, a conceptual framework for designing a parts procurement system for international co-operative knockdown production systems is proposed. Two types of pull-type parts procurement models that contain both a backorder function which modifies the backlog carried over from the last period and emergency delivery compensating for component part shortages, are formulated, and the effects of emergency delivery on the probability of stock out and the mean value of shortage quantity is analysed. Using these results, a computational procedure for determining an economic buffer stock level and emergency delivery rate or level which assures system reliability for a given performance level and minimizes the sum of inventory and emergency procurement costs, is presented.

A study of the design of a lot production system.

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.

Designing an effective production system for processing agricultural products

This paper deals with the problem of designing an effective production system for processing agricultural products, where raw materials, are harvested seasonally and have a limited shelf-life because of their perishability, although the market demand for the final products may be reasonably uniform throughout the year This model can clarify the relationship between production capacity and supply capability to the annual market demand, where the production system has two different types of processing processes and the number of workers hired by the plant is constant throughout the year. From the results of analysis, this paper proposes a method for designing an optimum production system under multiple-objective functions.

Trade-off analysis of buffer stock versus emergency delivery in the knockdown production systems

Abstract In the international co-operative knockdown production systems (ICKDPS), the transportation lead time to procure component parts is much longer than actual production lead time. Therefore, in designing an ordering system for the ICKDPS, it is necessary to decide an adequate buffer capacity in order to improve the system reliability for the transportation lead time. In this paper, we develop a new pull type ordering system, based on the concepts of just-in-time production systems, which incorporates a backorder function which modifies the back-log carried over from the last period, and includes two types of buffer capacities, that is, safety stock and emergency delivery for the ICKDPS. By trading off these two types of buffer capacities, we develop a way of determining an economical safety stock level and emergency delivery rate which will assure system performance reliability to any pre-determined level.

An approach to the design of production systems giving a high quality of working life and production efficiency

Peoples social and economic desires are gradually becoming more versatile and fragmented. Industries should be developed in such a way that these versatile human desires are brought into harmony with the organizational needs of production engineering. In this paper we report on the state of the desires and motivations of Japanese workers in 1974 and 1977 resulting from investigation and analysis using application methods of multivariate analysis and give an example of new production systems in which workers are in harmony with organizational needs.