Just-in-time manufacturing system: a periodic pull system

The just-in-time manufacturing system, as developed in the Toyota Motor Co., may be stated as producing or stocking ‘only the necessary items in necessary quantities at the necessary time’. When the just-in-time concept is applied to an industrial material management system, it is called a pull system, which means that the amount and time of material flow are determined by the rate and time of the actual stock consumption. Actually, in Toyota, this pull system is operated manually by means of a kanban, a sort of card or tag.

As an alternative to a kanban method, a periodic pull system (PPS) is developed as an operating policy of practising a Pull system. Due to the fact that, in a PPS, the manual information processing time of a kanban method is replaced with an instant on-line computerized processing, the material lead time is much shorter than that of a kanban system. This results in better system performance such as less lead time inventory and faster system response.

A PPS is formulated mathematically and a solution approach is provided for target stock levels, as well as the analysis of the fluctuations of in-process material flow, on-hand stock levels, target availability, etc.     

Development of ‘science TQM’, a new principle of quality management: effectiveness of strategic stratified task team at Toyota

To gain the position of a top runner of the 21st century, the effectiveness of?‘Science TQM’, a new principle of quality management, is proposed and discussed. The significance and effectiveness of?‘strategic joint task team activities’?for cooperative creation necessary for the development of?‘Science TQM’?are discussed. The formation of creative and?‘strategic stratified task teams’?(Tasks 1–8), and the verification of their effectiveness within Toyota and the Toyota group are proposed.     

People Pillars: Re‐structuring the Toyota Production System (TPS) House Based on Inadequacies Revealed During the Automotive Recall Crisis

Toyota has long been recognized as a leader in lean manufacturing and production quality through a dedicated practice of continuous process improvements and waste elimination techniques hallmarked within their Toyota Production System (TPS) and the ‘Toyota Way’ principles. Toyota's long list of successes and quality achievements has inspired companies within all industry sectors, not just automotive, to seek application of the coveted TPS into their process models in hopes of achieving the rewards that lean production promises. However, a recent series of automotive recall announcements associated with Toyota quality control have led many industry experts and students to reflect on possible inadequacies of the TPS House model. This article seeks to identify potential structural shortcomings and possible deficiencies of the TPS House in light of the root causes of recall crisis and suggest potential re‐structuring to better achieve continuous improvement. Copyright © 2016 John Wiley & Sons, Ltd.     

Optimal method for changing the number of kanbans in the e -Kanban system and its applications

The Toyota Motor Corporation has recently developed a new kanban system called ‘e-Kanban’, which is a parts ordering information system that operates within the communications network established between Toyota and its suppliers. One of the goals for developing the e-Kanban system was to introduce an efficient means for properly changing the number of kanbans once the required number has been calculated, as changing the number of kanbans in the kanban system directly affects the order quantity. Consequently, it is very important to monitor carefully and control changes in the number of kanbans. The paper investigates and proposes an effective method for changing the number of kanbans using the e-Kanban system. Applying this method to three problems, it is shown that the e-Kanban system can be implemented more efficiently and effectively than the original kanban system.     

准时制生产物流在中国汽车行业的应用

通过准时化物流的考虑方法以及在日本的发展状况,提出了两种重要的物流方式:巡回混载取货方式和中继地物流方式.在此基础上,分析了广汽丰田汽车有限公司准时制生产物流的应用情况,指出了三大物流运作模式的运用和操作的特点;为中国企业运用准时化物流提供了借鉴,并总结了中国企业发展准时制物流的可行性.     

Using the when/where rules in dual resource constrained systems for a hybrid push-pull control

This paper proposes a production control system, DRC-HPP, which uses the when/where rules in dual resource constrained (DRC) systems for a hybrid push-pull (HPP) control, to overcome some difficulties in modelling/implementing DRC/Kanban systems. These rules and the novel ‘process-or-transport’ and ‘whereto’ rules are embedded in some policies workers use to decide when to process (transport) parts, and where (whereto). Unlike most control systems, in which a group of workers is always responsible for transporting and another group is always responsible for processing parts, workers in DRC-HPP are responsible for both transporting and processing parts, as in the Toyota Sewn Products Management System (TSS). Yet, unlike TSS, DRC-HPP can be applied in any layout type. Workers transport parts when they are idle in part processing to enhance their utilisations and synchronise transportation. Since the transportation does not require special worker skills, the cost of training workers is not incurred. DRC-HPP is compared with different benchmarks through simulation experiments to evaluate its performance. It performs well under relatively short transportation times with respect to processing times. If they are relatively longer, the issue becomes to determine the number of workers to achieve a performance level. DRC-HPP also facilitates bottleneck management.     

Sequencing problem for a mixed-model assembly line in the Toyota production system

The paper discusses a sequencing problem of a mixed-model assembly line in the Toyota Motor Corporation production system, which is well known as the Just-in-Time production system. Whenever a worker in the assembly line finds that he might fail to complete his operations within the work zone, he pushes a button to call an auxiliary worker who assists him in the operations. If he can complete the operations within his work zone with the help of the auxiliary worker, the line does not stop. Otherwise, the line stops. In the Toyota production system, it is very important to keep a constant rate of usage of every part used by the assembly line. Hence, there are two goals for the sequencing problem in the Toyota production system. The paper provides a new formulation for the sequencing problem with two goals. It considers the goal of keeping the constant rate of part usage as a constraint of the sequencing problem, and it formulates a sequencing problem of minimizing the total line stoppage time with auxiliary workers and the constraints for keeping the constant rate of part usage. Since this problem is NP-hard and the size of the practical problems at Toyota are huge, a two-phase approximation algorithm is proposed. Numerical examples show that the proposed algorithm is efficient and can find a good suboptimal solution.     

Testing a theoretical model underlying the ‘Toyota Way’ – an empirical study involving a large global sample of Toyota facilities

In this paper, we empirically test the theoretical model underlying the Toyota Way (TW), based on data obtained from Toyota’s logistics, sales and marketing functions across 27 countries. TW is the result of Toyota attempting to codify its culture to the global community. Using structural equation modelling techniques we show that the TW-associated measures challenge, kaizen, genchi genbutsu, respect and teamwork do adequately operationally define the TW; the first three measures corresponding to the construct ‘process improvement’ and the final two measures corresponding to the construct ‘people development’. Empirically, people development is found to have no direct effect on how the TW is deployed across a business unit. However, people development is found to be indirectly related to TW deployment through the mediating effect of process improvement. Our study provides quantitative evidence that while the intangible aspects of the TW (modelled as people development) may not directly relate to the results, they are an integral component of a complete implementation of the TW and related ‘Lean’ systems. By logical extension, this provides support for adoption of a holistic and long-term strategy, integrating soft and hard elements, by those organisations attempting to implement and sustain Toyota-style systems.     

World-class manufacturing by Fiat. Comparison with Toyota Production System from a Strategic Management,Management Accounting,Operations Management and Performance Measurement dimension

Toyota Production System (TPS) and the derived lean production have cast a shadow over the models of world-class manufacturing (WCM). Yet, some groups such as Fiat have reinvented WCM. Fiat’s WCM is quickly becoming a sort of alternative to TPS-lean production. By means of semi-structured interviews and a direct observation of the documentation of Fiat’s model, this research wants to find the theoretical elements that underpin the model. The methodology is mainly based on grounded theory. The theoretical elements were coded and classified within four dimensions: strategic management, management accounting, operations management and performance measurement system. The four dimensions and their elements were compared for the first time with the same dimensions of TPS-lean production. Fiat’s WCM seems to have a ‘grand strategy’ focused on quality and cost savings where quality must be reached with no trade-off with other strategies. Safety is pursued above all else and Fiat’s WCM cannot be implemented without this first achievement. A particular system called ‘cost deployment’ measures wastes and losses on processes. The performance measurement system is structured and fosters day-by-day management as well as computer-based management. Furthermore, the performance measurement system is based on a complex and formal auditing and benchmarking process.     

An interview based study of two United Kingdom and two Japanese suppliers to Toyota

Through interviews conducted in the UK and Japan this research examines and rates the problems and the differences between two UK and two Japanese companies which are suppliers to Toyota Motors in Toyota City Japan, and Toyota Motor Manufacturing UK Ltd in Derby. This information, in conjunction with relevant examples of problems which Japanese transplant operations have encountered in the United States, is used to anticipate the range of problems that Toyota need to address when operating in the UK. As a consequence, problem scenarios with Japanese transplants are posed and possible solutions are offered.     

Integrated quality and quantity modeling of a production line

During the past three decades, the success of the Toyota Production System has spurred much research in manufacturing systems engineering. Productivity and quality have been extensively studied, but there is little research in their intersection. The goal of this paper is to analyze how production system design, quality, and productivity are inter-related in small production systems. We develop a new Markov process model for machines with both quality and operational failures, and we identify important differences between types of quality failures. We also develop models for two-machine systems, with infinite buffers, buffers of size zero, and finite buffers. We calculate total production rate, effective production rate (ie, the production rate of good parts), and yield. Numerical studies using these models show that when the first machine has quality failures and the inspection occurs only at the second machine, there are cases in which the effective production rate increases as buffer sizes increase, and there are cases in which the effective production rate decreases for larger buffers. We propose extensions to larger systems. Correspondence to: Stanley B. GershwinWe are grateful for support from the Singapore-MIT Alliance, the General Motors Research and Development Center, and PSA Peugeot-Citroën.     

Empowering Kanban through TPS-principles – an empirical analysis of the Toyota Production System

The purpose of this paper is the empirical investigation of the Toyota Production System in order to test existing relationships as they are proposed in theory. The underlying model consists of seven factors reflecting the key practices of the Toyota Production System. Using data from 188 manufacturing plants participating in the High Performance Manufacturing research project, the model's measurement characteristics were validated through confirmatory factor analysis. Path analysis of the model showed that the majority of the relationships can be confirmed. Furthermore, a comparison of mean analysis based on a conducted cluster analysis indicates that plants with a higher implementation degree of the practices of the Toyota Production System also show a higher perceived performance in terms of the key criteria of production, i.e. time, cost, quality, and flexibility.     

MRP和JIT两种生产管理系统的比较研究

长期以来，人们对ＭＲＰ和ＪＩＴ两种生产管理系统孰优孰劣一直争论不休。一方面，源于日本丰田公司看板系统的ＪＩＴ生产管理系统，随着日本经济的成功，使得许多人相信它在减少库存和在制品、缩短生产准备时间和生产提前期方面从根本上优于ＭＲＰ管理系统；另一方面，许多应用ＪＩＴ生产管理系统的企业并没有取得预期的经济效益，甚至生产效益没有任何改善。本文的目的，是通过建立两种生产管理系统的模型，进行计算机仿真研究，定     

Production projects – designing and operating lifecycle-oriented and flexibility-optimized production systems as a project

Due to fast changing markets and ever shorter product lifecycles, lifecycle-orientation and flexibility can be described as major factors for success. As an answer to the resulting challenges this paper introduces the concept of Production Projects. According to the concept either a single production line or an entire production location can be planned and operated as a project. Thereby, Production Projects form the organizational base to link the lifecycles of products and production systems and to optimize the degree of flexibility of the latter. Within Production Projects the traditional project target dimensions?‘quality’,?‘time’?and?‘cost’?are supplemented by?‘flexibility’?as a fourth target dimension. Major elements within the concept are the so-called Production Project Master Schedule, Process Modules, and the Flexibility Mode and Effect Analysis (FlexMEA). The Production Project Master Schedule consists of standardized phases for the lifecycle-oriented design and operation of a production system. Based on the Master Schedule, the standardized building blocks of a production system, so-called Process Modules, can be relocated within and in between production locations. With the FlexMEA, an innovative method is introduced, which enables an enterprise to plan and monitor the degree of flexibility of its production systems and to derive flexibility optimizing measures if necessary.     

Changes in Toyota Motors’ operations management

A key driver behind Toyota Motors’ rise to prominence has been the Toyota Production System (TPS). This pillar of the firm's competitive strength was developed over several decades. As of the late 1980s, various changes were introduced into the TPS. Some of these, such as line segmentation, the use of inter-segment buffers and high-tech automation, have been portrayed as breaks with TPS foundations. With virtually no exception published accounts on these changes stop with the situation in the mid-1990s. Based on general literature and three factory visits, this article aims to provide an update on the situation in April 2001.     

On the choice of a production control system

This paper deals with a problem to develop ‘factory automation systems’ which harmonize companies’ needs with workers’ desires. Two kinds of indices and methods of survey are proposed on the basis of the ‘fusion system concept’. One is that of the state of workers’ desires which are based on the ‘stimulus-response model’, the other is that of situations where ‘factory automation’ is implemented in a workshop. The effects of ‘factory automation’ on workers’ desires are clarified in a study of Japanese manufacturing industries in 1983. As a result of this investigation, some problems can be pointed out which should be solved in the future to develop ‘factory automation systems’.     

Flexibility of production ordering systems

The flexibility of production ordering systems as medium range production control systems are studied. The changes affecting flexibility, production ordering systems as responses to changes, and the performance measures of flexibility are clarified. On the basis of this framework, mathematical models of production system and production ordering systems are developed to evaluate their flexibility. Two types of changes are considered: demand fluctuation and downtime fluctuation due to machine breakdown, and two models for ‘push-type’ and ‘pull-type’ production ordering systems are investigated. By simulating the models, the amplifications of production quantities and inventory levels as flexibility measures for each type of production ordering system are analysed and the flexibility compared.     

Using age and usage for prediction of reliability of an arbitrary system from a finite population

For single‐use non‐repairable systems, reliability is commonly estimated as a function of age and usage. For the effective management of individual systems or populations of systems, it is frequently important and necessary to predict the reliability in the future for age and usage values not yet observed. When predicting future system reliability, the age of the future system is easily predicted whereas future usage values will typically be unknown. In this paper we present the methodology for how to estimate both individual and population reliability summaries based on the currently known age and usage values. Projected usage values for future points in time can be obtained based on observed usage patterns or user‐specified patterns of usage rates. Individual system summaries can be used to answer the questions ‘For a given system of age A and usage U, what is its reliability with associated uncertainty?’ or ‘For a given system with known current age A and usage U, but unknown usage in the future, what is its reliability with associated uncertainty?’ The population summary of interest predicts the probability that a system randomly selected from the population of systems works. This summary takes into consideration the estimation of future usage, the estimated probability of individual systems working at their given ages and usage values, and the life cycle demographics of the population of interest. In this paper we discuss these questions for a given application. Published in 2010 by John Wiley & Sons, Ltd.     

An ISM approach for modelling the enablers of flexible manufacturing system: the case for India

The volatile condition of today's market is forcing the manufacturing managers to adapt the flexible manufacturing systems (FMS) to meet the challenges imposed by international competition, ever changing customer demands, rapid delivery to market and advancement in technology. There are certain enablers, which help in the implementation of FMS or in the transition process from traditional manufacturing systems to FMS. The utmost need is to analyse the behaviour of these enablers for their effective utilization in the implementation of FMS. The main objective of this paper is to understand the mutual interaction of these enablers and identify the ‘driving enablers’ (i.e. which influence the other enablers) and the ‘dependent enablers’ (i.e. which are influenced by others). In the present work, these enablers have been identified through the literature, their ranking is done by a questionnaire-based survey and interpretive structural modelling (ISM) approach has been utilized in analysing their mutual interaction. An ISM model has been prepared to identify some key enablers and their managerial implications in the implementation of FMS.     

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

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.