Competitive Priorities in Operations Management

Identifying manufacturers' competitive priorities has long been considered a key element in manufacturing strategy research. However, relatively little effort has been devoted to measurement of these constructs in published research. In this study we develop scales for commonly accepted competitive priorities, cost importance, quality importance, delivery-time importance, and flexibility importance. We assess how well the scales capture the constructs that they represent using data collected from 114 manufacturing plants in the United States. The findings suggest that the instrument developed can provide reliable data and that the constructs measured are valid. In addition, comparisons between pairs of informants representing the same business indicate that the perceptual measures of competitive priorities are as reliable as point estimates of routine, seemingly objective information.     

Implementation of just-in-time in a small company: A case study

This paper deals with the implementation of JIT in a small company in Taiwan that produces different kinds of automobile lamps such as rear combination lamps and front turn signal lamps. JIT systems have tremendous effects on all operations of a firm, including design, accounting, finance, marketing, distribution, etc., and thus are of interest to all levels of a firm's management. Realizing the success of JIT, large-scale manufacturing companies all over the world have implemented JIT in their production systems with the objective of improving their competitiveness. Nevertheless, small and medium enterprises SMEs play a major role in the national economy. However, JIT has not received serious attention from SMEs. Realising the importance of improving the performance of SMEs, a case study is presented to motivate practitioners to implement JIT in their SMEs. In addition, future research directions in the areas of implementing JIT in SMEs are presented.     

An information system for Just-In-Time

In recent years, U.S.'s worldwide industrial and economic leadership has been seriously challenged by many foreign countries. In order to counter the problem, many U.S. manufacturing companies have sought effective materials management systems such as MRP and the ‘Just-In-Time’ (JIT) system as used by many Japanese companies. Even through many practitioners and academicians have been studying the JIT concept and have recommended ways of adapting the concept to the U.S. manufacturing environment, not very many organizations are enjoying benefits of JIT system in full scale because of misunderstanding of information needs in JIT system. The objectives of this paper are (1) to identify information requirements of the materials management systems under JIT concept, (2) to compare them against the requirements under MRP system, and (3) to propose an integrated management information system to support materials management system in JIT environment. The goal of this paper is to facilitate more effective implementation of the JIT system, and stimulate further research on the subject matter.     

Supply chain management: A just-in-time perspective

Just-in-time (JIT) has been a widely recognized production philosophy alternative since the early 1980s. JIT principles and techniques have been widely adopted in many manufacturing firms. More recently, supply chain management has evolved as a discipline focusing on the design, planning and control of processes linking the initial raw materials to the ultimate consumption of the finished product. Supply chain efficiency is dependent on the efficiencies of the individual manufacturing organizations and the ability to connect along the supply chain. In this paper supply chain management from a JIT perspective is investigated, focusing on the linking mechanisms between successive companies and the collective efficiency of the supply chain.     

Just-in-time purchasing: an empirical investigation

The just-in-time (JIT) literature suggests that, for JIT to be successful, a manufacturing firm has to make changes in its purchasing operations. However, empirical examination of the JIT purchasing related issues is limited. For example, a literature search identified 49 JIT purchasing articles. Of these, only 14 are empirical studies; two dealing with statistical testing of a few JIT purchasing issues. This comprehensive empirical study is undertaken to investigate (a) changes in the purchasing attributes since JIT implementation, (b) supplier evaluation cri-teria, and (c) problems with JIT purchasing implementation. Statistically significant changes are observed in 28 out of 32 attributes identified in the literature, suggesting that the manufacturing firms are successfully implementing JIT purchasing programmes. Of the 14 supplier evaluation criteria, the empirical investigation shows nine of them being important. Erratic demand for the product and customized product are found to be problematic (but not very problematic as suggested in the JIT literature( in JIT purchasing implementation.     

Optimizing lot size and setup time in a JIT environment: a multiple objective application

The just-in-time (JIT) system has been studied extensively and implemented by a number of US firms as an ell'ective production system. The core of JIT involves determination of lot size and setup time reduction so as to increase manufacturing flexibility while minimizing the inventory level. This decision problem usually involves multiple conflicting objectives and mixed-model production. In this paper, goal programming (GP) is applied to a real-world JIT problem involving fabrication of different automotive and industrial rubber composite belts. The model results provide new insights concerning the conflicting nature of several goals, especially between meeting demand and reducing setup or idle time. Also, the GP solution is superior to the current JIT practice of the company.     

Some structural properties for the just-in-time level schedule problem

Just-in-time (JIT) is a pull concept applied mainly in repetitive manufacturing systems, and it is characterized by a scenario where only the required units are produced in the required quantities at the required times. It particularly aims at eliminating wastes associated with inventories in the system. A level schedule is desirable for a JIT assembly system, as it serves as an approximation for all forms of smoothing. The min-sum formulation of the assembly line level schedule problem is one of those that has been mainly used in the literature. Using this formulation as a base, we develop some useful structural properties for the problem. Among other things, it is shown that a level schedule would tend to be more difficult to achieve for products (models) with comparatively fewer units in the products composition structure.     

精益生产组成要素之间的关系研究

基于资源基础理论探讨精益生产组成要素之间的关系,并以华南地区118家制造企业为研究样本进行实证研究。研究结果表明:员工参与正向影响TQM/TPM,但对JIT的实施并没有直接的影响,需要通过TQM/TPM间接影响;TQM正向影响TPM的实施;TQM、TPM正向影响JIT,且TQM通过TPM间接影响JIT。研究结论对精益生产的相关理论和实践都有重要的价值和意义。     

Implementation of just-in-time methodology in a small company

This paper describes the implementation of JIT in a small manufacturing company and the benefits that resulted for the company's operations. Preliminary analysis identified various problems in the existing manufacturing operations. The pre-implementation and post-implementation conditions of the company arc detailed. The achievements of the JIT implementation included a reduction in material traversing, reduced lead limes and inventories leading to an overall reduction in the cost of manufacturing. A smooth flow of material from the raw material stage to the finished product stage was established. Three separate product lines were combined into a flexible manufacturing assembly line. With the adoption of a holistic approach to JIT implementation, it was found that even a small company can make significant strides towards world class manufacturing status. The experience gained by the company can encourage and benefit other small companies to embrace the JIT approach.     

A structured methodology to implement judiciously the right JIT tactics

In order to enhance the competitiveness and efficiency of manufacturing operations, many companies arc looking at implementing key strategic technologies. Two of the most predominant programs are ‘just-in-time’ and ‘synchronous organizations’. However, their impacts on improving quality and reducing time-to-market have been mixed. It is not very clear why, in some cases, results are poor, when in a similar situation, programmes have proved to work well. There are conflicting reasons reported for such a discrepancy. Some have argued that during J IT implementation either a right mix of tactics was not selected at the outset or the process was not carefully monitored to see whether a mid-course correction or change in tactics was necessary. In order to (a) protect the manufacturing and strategic teams from making the same/similar mistakes and (b) sustain a series of successful activity throughout during the strategic implementation cycle, this paper outlines a structured methodology. The method utilizes a matrix-based procedure to dynamically (over time) measure the effectiveness of a line of JIT tactics against the organization's principles and objectives. The operating procedure suggests first (a) using a method for monitoring the changing conditions of market and business and then (b) using the metrics to guide the management with a new line of tactics that might have better impact on the newly aligned company goals. In an effort to help managers and engineers decide on a proper line of tactics to implement JIT, a line of JIT quality matrices (JQM) is developed. JQM provides a framework to guide group managers to ‘plan, pick and choose’ a set of effective JIT techniques. An approach similar to quality function deployment (QFD) is used to generate the JIT house and their corresponding JQM matrices. With the JQM-based structured methodology, managers can design the best line of JIT strategy blended with JIT theory and adapted to the manufacturing environments in which it is expected to operate.     

Organizational modifications to support JIT implementation in manufacturing and service operations

This study investigates JIT implementation practices and performance in manufacturing and service organizations in the US. Literature related to JIT usage and performance in both sectors is reviewed. A field study is then conducted to investigate the actual implementation experiences of a selected group of service and manufacturing users of JIT. Our findings from the literature and the field study are used to develop four research hypotheses that are tested using survey data from 130 manufacturing and 61 service firms. Manufacturing and service firms that had engaged in modifications such as operator and management training and improving linkages with suppliers prior to implementing their JIT systems experienced less implementation problems and achieved higher levels of success than firms that placed less emphasis on these modifications. This paper details and discusses these and other results from our study. In addition, managerial implications of our findings are presented.     

Distinguishing Features of Just-in-Time Systems in the Make-to-Order/Assemble-to-Order Environment*

Few studies of just-in-time (JIT) implementation examine their significance in make-to-order manufacturing environments. This study examines the relative importance of several operating variables that are characteristic features of JIT systems within such environments in North America. The results suggest that the most salient features of JIT for make-to-order and assemble-to-order firms are the elimination of waste (in the form of time and defects), reduced setup time, reduced lotsize, and a smaller pool of suppliers. In addition, the results suggest that the use of non-domestic suppliers can possibly hinder efforts at JIT implementation of materials procurement.     

HRM practices of JIT firms in Canada

Many firms have adopted the just-in-time (JIT) philosophy to compete successfully in the global environment. The literature suggests that die success of JIT implementation depends on sound human resource management (HRM) practices that will attract, maintain, and retain employees with the required workforce characteristics. However, only a few field studies investigate the effectiveness of such practices. This empirical study examines HRM practices of 69 JIT manufacturing firms in Ontario, Canada. Specifically, it identifies important workforce characteristics, recruitment sources and selection instruments used by JIT firms. It also evaluates die degree of change in training, compensation, employee retention, and labour relations practices in the firms since JIT implementation. The level of attainment of various expected outcomes of JIT implementation and die competitiveness of the JIT firms are investigated. Problems faced by HRM managers are also discussed.     

Measuring Modularity‐Based Manufacturing Practices and Their Impact on Mass Customization Capability: A Customer‐Driven Perspective

As uncertainty in markets and technology intensifies, more companies are adopting modular product and process architectures to cope with increasing demands for individually customized products. Modularity‐based manufacturing is the application of unit standardization or substitution principles to create modular components and processes that can be configured into a wide range of end products to meet specific customer needs. This study defines modularity‐based manufacturing practices (MBMP), develops a valid and reliable instrument to measure MBMP, builds a framework that relates customer closeness, MBMP, and mass customization capability, and tests structural relationships within this framework using LISREL. Based on 303 responses from members of the Society of Manufacturing Engineers, statistically significant and positive relationships were found among customer closeness, modularity‐based manufacturing practices, and mass customization capability. Managerial implications of the empirical findings of this study and future research directions are also discussed.     

Transportation Approach to Locating Plants in Relation to Potential Markets and Raw Material Sources

Proximity to the market place has been considered the most important locational factor in the literature so far. However, the growing need for frequent deliveries of materials in smaller lot sizes for just-in-time (JIT) manufacturing prefers plants closer to the raw materials sources. Locating plants for JIT manufacturing is, therefore, a problem of finding the right balance between the requirements of procurement and distribution. A comprehensive model is proposed in this paper to solve this problem. The model is solved by using the transportation algorithm and produces simultaneous decisions on procurement, production, and distribution. The model does not require plant sizes to be known a priori, but it allows upper limits to be placed on the size of each plant and raw material source. As such, optimal plant capacities along with the corresponding procurement and distribution quantities are all determined by the model solution.     

Adoption of just-in-time based quality assurance and purchasing practices

Feasibility of transforming purchasing and quality control operations from conventional to just-in-time (JIT) practices is discussed. The study is confined to the dock-to-stores area of an engine manufacturing plant. Components used in the study are selected from a representative sample of inventory classes, commodity groups and agreement types with vendors. A time/cost analysis is carried out for the components selected so as to evaluate the cost effectiveness of the conventional purchasing and quality control. Findings on savings in terms of inventory-related costs and inventory turnover through the implementation of JIT practices are reported. A transformation framework is then developed to determine the suitability of individual components for JIT based practices. Cases are presented to demonstrate the functioning of the framework.     

Computational complexity of algorithms for MRP and JIT production planning problems in enterprise resource planning systems

An enterprise resource planning system (ERP) is the information backbone of many manufacturing companies. At the core of ERP is a conventional material requirements planning (MRP) production planning system or a variation of MRP when just-in-time (JIT) principles are used in manufacturing. MRP and JIT both organize production planning into a hierarchy of long-, medium- and short-range problems. In all there are eight different problems. Some are common to MRP and JIT, others are specialized for a particular system. This paper analyses the computational requirements of these problems. This is important for ERP because it plans for large numbers of products (e.g. 50 000 products at 3M Company and 44 000 products at States Industries in Oregon) at large numbers of locations (e.g. 82 locations in 21 countries for Visteon Automotive Systems of Michigan and 19 locations at Boeing). We show that adequate algorithms exist for some problems, but better algorithms are needed for other problems if ERP is to provide useful production plans.     

The sensitivity of job mix and load capacity bottlenecks on inventory and due date performance in a manufacturing system

Based on a benchmark job-lot manufacturing system a simulation study was carried out to compare the performance of just-in-time (JIT) shop control system Kanban with conventional job-shop control procedures. The shop control policies were tested under a good manufacturing environment and the effects of job mix and load capacity bottlenecks on various shop control policies were tested. From the simulation results, it is inferred that there are shop control procedures that perform better than the Kanban in a job shop. It has been observed that even with adequate capacity, bottleneck areas surface due to fluctuations in the shop load. Kanban is not appropriate in such a situation because capacity bottlenecks can significantly reduce the ell'ectiveness of a pull system. The disparateness in the processing requirements for jobs can seriously undermine the performance of the shop. This is the type of shop environment where the shop control procedures will be most effective. Although Kanban came out best when the load capacity bottlenecks and the disparateness of the job mix were removed, the selected shop control variable combinations closely approximated the Kanban result. Although many features of JIT can be implemented in any system, companies trying to adopt JIT should remember that Kanban requires a rigid system intolerant of any deviation.     

Planning and Control in Multi-Cell Manufacturing

This research compares Material Requirements Planning (MRP), Kanban, and Period Batch Control (PBC) as alternative approaches to the planning and control of multi-cell manufacturing involving flow cells and assembly. Since previous research on performance of these systems in cellular manufacturing has been primarily conceptual, the experiments reported here provide new insights into their comparative performance. The results show that the production environment is a major factor in system choice. Three operating factors—Master Production Schedule (MPS) volume variation, MPS mix variation, and setup time/lot size—clearly affect system choice. All systems performed well under Justin-Time (JIT) conditions; there was no advantage to Kanban. Under the mixed conditions of high MPS variation, but small setup time/lot sizes, PBC produced superior performance compared to Kanban and MRP. Under non-JIT conditions, MRP was seen as clearly more effective. Finally, the results indicate that when conditions permit very small lot sizes relative to requirements, Kanban may perform best, even when MPS variation is high.