The impact of critical success factors of JIT implementation on organizational performance

Much has been written and publicized about the virtues of JIT philosophies during the past decade. However, relatively limited empirical research has been reported con-cerningJIT implementation on organizational performance. This study presents the results of an empirical study which utilized both concrete financial accounting data and a broad cross-sectional survey as measures of organizational performance to determine the impact of each JIT implementation requirement factor to organizational performance. Communication between production and marketing departments was identified as a critical factor for increased inventory turnover and work-in-process inventory turnover, while employees' participation and the bottom-up management approach were determined as significant factors for improving quality and flexibility. The results of this study imply that in JTT environment personnel management practices, such as bottom-up management encouraging employees participation, and organization management such as a communications linking the production and marketing departments, are more important than JIT practices themselves.     

A multicriteria model for supporting setup reduction investment decisions

One critical manufacturing challenge of the 1990s is for firms to effectively apply new operations management techniques while embracing wider philosophies such as total quality management (TQM) and computer integrated manufacturing (CIM), etc. Setup cost and/or time reduction is one such technique capable of producing many benefits for manufacturing firms, including reduced inventory, better equipment utilization, and improved quality. It is thereby viewed as an important component of just-in-time (JIT) manufacturing practice. Existing problems with the setup reduction decision include the many factors that must be considered, as well of an absence of validated and usable models for estimating potential benefits from setup reduction investment made in different contexts. This paper discusses the attainment of gains from setup reduction mainly by improving existing equipment and work practices rather than purchasing new equipment or technology. The model proposed in this paper is based on the application of the analytic hierarchical process (AHP) on seven weighted factors to obtain a preliminary indication as to whether investment in setup reduction is desirable in a given manufacturing context, and the expected benefits of such investment. A flexible scaling system, thus obtained, allows the model to handle a wide range of managerial predispositions to setup reduction.     

Economic Manufacturing Quantity and Its Integrating Implications

Several contradictions are noted among the Economic Order Quantity (EOQ), Just‐In‐Time (JIT), and Optimized Production Technology (OPT) approaches and the economic framework for profit maximization. A fundamental model referred to as the Economic Manufacturing Quantity (EMO) is developed and examined for its integrating implications for the three approaches. An implication for the classic EOQ approach is that the balance between setup and inventory carrying costs is valid when a production facility is operating at or below a certain critical level but not when operating above that level. An implication for the JIT approach is that one must reduce setup cost at non‐bottlenecks and setup time at bottlenecks to reduce inventory. An implication for the OPT approach is that trade‐offs between setup and inventory carrying costs may indeed be ignored while determining process batch sizes, provided each facility in a production system is operating at or above Its critical level. Economic theoretic analysis of the EMO model provides a basis for unification of JIT which advocates stability in operating level as a key to improved productivity and quality, and OPT that advocates maximizing operating level with resultant emphasis on bottlenecks as a key to increased profits. This unifying basis states that a profit‐maximizing production facility or system will operate at the full and stable level as long as market demand remains relatively sensitive to price and operating at the full (maximum) level provides positive unit contribution.     

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.     

Impact of Information Technology Integration and Lean/Just‐In‐Time Practices on Lead‐Time Performance*

Managers seeking to improve lead‐time performance are challenged by how to balance resources and investments between process improvement achieved through lean/just‐in‐time (JIT) practices and information technology (IT) deployment. However, extant literature provides little guidance on this question. Motivated by both practical importance and lack of academic research, this article examines empirically the relationships among interfirm IT integration, intrafirm IT integration, lean/JIT practices, and lead‐time performance using data from IndustryWeek's Census of Manufacturers ( IndustryWeek, 2006 ). The results provide several new insights on the relationship between IT integration and lean/JIT practices. First, the study confirms that implementing lean/JIT practices significantly reduces lead time. Second, lean/JIT practices mediate the influence of IT integration on lead‐time performance. This suggests that process improvements that result from lean/JIT practices are important contributors to the success of IT integration. Even companies that have experienced success in reducing lead time through lean/JIT practices may benefit from IT integration practices such as those embodied in enterprise resource planning systems. The findings provide managers with empirical evidence and a theoretical framework on the balance between lean/JIT and IT for effecting improvement in lead‐time performance, thus offering practical guidance on this important question. Future research is needed to extend the lean/JIT practices in this study to supply chain practices and explore the relationship between supply chain practices and IT integration.     

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.     

An integrated vendor-buyer cooperative inventory model for items with imperfect quality

This article develops a model to determine an optimal integrated vendor-buyer inventory policy for flawed items in a just-in-time (JIT) manufacturing environment. The aim is to minimize the total joint annual costs incurred by the vendor and the buyer. The proposed model extends the integrated vendor-buyer inventory model by accounting for imperfect quality items. The expected annual integrated total cost function is derived and an analytic solution procedure is proposed to determine the optimal policy. Finally, numerical examples are also given to illustrate the solution procedure presented in this article.     

JIT purchasing: attribute classification and literature review

To find critical JIT purchasing attributes for manufacturing industry, 56 refereed articles are reviewed. These articles are categorized as conceptual, case and empirical studies. Thirty-four attributes are thus identified. An input-output model is developed to classify these attributes. The inputs to JIT purchasing environment consists of buyer, supplier and joint buyer-supplier actions with 13, six and six attributes, respectively. The interaction between these attributes leads to the JIT purchasing environment. Output of this environment consists of nine attributes. By using the frequency of citation of an attribute as a measure of its importance, consensus is found among conceptual and case studies regarding those attributes of JIT purchasing considered critical. However, many of these attributes have not been investigated empirically, while others have not been rigorously examined. Common supplier evaluation criteria are identified. Benefits and problems with JIT purchasing implementation are discussed. Analysis suggests the need for comprehensive and statistically rigorous empirical studies.     

Relationships among JIT practices: an interpretive modeling approach

Abstract

This research develops a model of relationships among components of Total-JIT, including JIT-information, JIT-manufacturing, JIT-purchasing, and JIT-selling, to establish an implementation hierarchy based on relative importance. The data collected relates to the relationships among JIT components and two performance measures, supply chain competency and organizational performance. Two groups are used in the research, one group of five operations management academics and another group of 30 practicing operations managers working in U.S. manufacturing firms. An interpretive structural modelling methodology is used to develop alternative structural models. The academics’ data show JIT-information emerging as lynchpin of relationships, directly impacting all other JIT practices and both performance measures. The practitioners’ data indicates that all JIT practices and performance measures are interactive as components and outcomes. This study is the first to apply interpretive structural modelling to investigate the interplay among total-JIT components and the performance measures of supply chain competency and organizational performance.     

Materials receiving capacity and inventory management

This paper analyses the optimal level of materials receiving capacity for a manufacturer that receives deliveries from many suppliers. Inventory levels and inventory carrying costs depend on the frequency of deliveries and thus, on the materials receiving capacity. An analytic model that captures the tradeoff between inventory costs and materials receiving costs is presented and discussed. The receiving cost is modeled as increasing in discrete jumps of varying sizes whenever materials receiving resources are added. Practical issues in implementing the model are highlighted and methods to reduce the marginal materials receiving cost are discussed. The paper also discusses connections to the JIT approach for production environments where materials receiving is heavily automated.     

Integrated procurement- production system in a just-in-time environment-modelling and analysis

Classically, economic lot size models have been used separately for procurement and production subsystems. However, when the raw materials are used in production, the procurement policies are dependent on the schedule and the batch size for the product. Hence, it is necessary to unify the procurement and production policies. The just-in-time JIT environment provides an ideal setting for such a coordination between the procurement and production policies. The model proposed here is a traditional inventory model recast into a model for a JIT system for a single product, multistage batch environment aiming at the minimization of total variable cost and thereby determining the batch sizes for the product and raw material order sizes. A JIT system aims at minimizing setup time and this feature is captured in the proposed model. The computational experience reported in this paper is based on a number of simulated problem sets. The possible domain of application is also highlighted.     

考虑顾客缺货反应的多产品两阶段JIT联合订货

为了解决多产品两阶段联合订货决策问题,综合考虑顾客缺货反应及资源限制对订货决策的影响,提出资源限制条件下考虑CRS的多产品两阶段JIT联合订货策略。在此基础上,以零售商收益最大化为目标,建立了多产品两阶段JIT联合订货决策模型,并从初始解生成和殖民地国家革命方式两方面设计了改进的帝国主义竞争算法。从Gruen调查报告中选取三种不同规模的算例验证了模型和算法的适用性和有效性。研究表明：本文提出的考虑顾客缺货反应的多产品两阶段JIT联合订货方法既可以提高零售商的总收益,也能提高顾客的服务水平;当单位库存资源机会收益相近时,同组产品间不会发生替代情况,而当同组产品间的单位库存资源机会收益差距较大,且高于其他产品组的单位库存资源机会收益时,则该产品组便会出现缺货和替代情况,且若该组缺货产品的剩余资源单位机会收益小于其他组产品的单位资源机会收益,则该产品的剩余资源便会转移给其他缺货产品。研究结论可为零售商多产品两阶段JIT联合订货决策提供有益的参考。     

WIP inventories in the simultaneous determination of optimal production and purchase lot sizes

This paper studies an integrated production and purchasing lot sizing model with work-in-process WIP inventory. In this model, the single product is made in a multiprocess manufacturing system. The raw materials are procured from outside sources and are converted gradually into the product. A solution procedure is developed to simultaneously find the optimal lot sizes for the product and its raw materials and the corresponding total relevant cost. It is shown that if the cost of WIP inventory is considered in the production lot size computation, the optimal lot sizes of the product as well as those of the raw materials could be altered significantly.     

Determination of recovery effort for a probabilistic recovery system under various inventory control policies

In this study we investigate the desired level of recovery under various inventory control policies when the success of recovery is probabilistic. All the used and returned items go into a recovery process that is modelled as a single stage operation. The recovery effort is represented by the expected time spent for it. The effect of increasing recovery effort on the success probability together with unit cost of the operation is included by assuming general forms of dependencies. Alternative to recovered items, demand is satisfied by brand-new items. Four inventory control policies that differ in timing of and information used in purchasing decision are proposed. The objective is to find the recovery level together with inventory control parameter that minimize the long-run average total cost. A numerical study covering a wide range of system parameters is carried out. Finally computational results are presented with their managerial implications.     

Selection of resilient supply portfolio under disruption risks

This paper deals with the optimal selection and protection of part suppliers and order quantity allocation in a supply chain with disruption risks. The protection decisions include the selection of suppliers to be protected against disruptions and the allocation of emergency inventory of parts to be pre-positioned at the protected suppliers. The decision maker needs to decide which supplier to select for parts delivery and how to allocate orders quantity among the selected suppliers, and which of the selected suppliers to protect against disruptions and how to allocate emergency inventory among the protected suppliers. The problem objective is to achieve a minimum cost of suppliers protection, emergency inventory pre-positioning, parts ordering, purchasing, transportation and shortage and to mitigate the impact of disruption risks by minimizing the potential worst-case cost. As a result a resilient supply portfolio is identified with protected suppliers capable of supplying parts in the face of disruption events. A mixed integer programming approach is proposed to determine risk-neutral, risk-averse or mean-risk supply portfolios, with conditional value-at-risk applied to control the risk of worst-case cost. Numerical examples are presented and some computational results are reported.     

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.     

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.     

An Analysis of Dual‐Kanban Just‐In‐Time Systems in a Non‐Repetitive Environment

Recent advances in approaches and production technologies for the production of goods and services have made just‐in‐time (JIT) a strong alternative for use in intermittent and small batch production systems, especially when time‐based competition is the norm and a low inventory is a must. However, the conventional JIT system is designed for mass production with a stable master production schedule. This paper suggests supplementing the information provided by production kanbans with information about customer waiting lines to be used by operators to schedule production in each work‐station of intermittent and small batch production systems. This paper uses simulation to analyze the effect of four scheduling policy variables—number of kanbans, length of the withdrawal cycle, information about customer waiting lines, and priority rules on two performance measures—customer wait‐time and inventory. The results show that using information about customer waiting lines reduces customer wait‐time by about 30% while also reducing inventory by about 2%. In addition, the effect of information about customer waiting lines overshadows the effect of priority rules on customer wait‐time and inventory.     

Human resource management in the just-in-time environment

Successful just-in-time (JIT) implementation requires a multiskilled group-oriented and self-disciplined workforce with good quantitative skills. Little discussion exists in the JIT literature concerning the development of such a workforce. The human resource management (HRM) literature deals with employee issues but does not identify strategies for achieving a JIT workforce. In order to identify appropriate HRM strategies for a JIT environment, a comprehensive model is presented to show the critical linkage between JIT and HRM. Interactions between legal issues, management and union, and human input are examined. The impact of US labour laws on HRM practices is discussed and contrasted with Japanese practices. The literature review of HRM-related JIT articles suggests that HRM practices in the areas of staffing, training and development, compensation, and employee retention can be used to develop an effective JIT workforce. The article will help production managers to understand the impact of specific HRM strategies that are appropriate for developing a JIT workforce.     

An Evaluation of the NERJIT Priority Rule in a Kanban‐Controlled Flowshop

Significant progress in production and information technologies and innovations in management of operations during the last couple of decades have made the production of small lots and deployment of Just‐In‐Time (JIT) concepts in flowshops possible. As a result, some researchers and practitioners have been seeking to improve the performance of non‐repetitive systems using JIT concepts. In this process, the JIT concepts that were originally designed for mass production have been modified to adapt JIT to non‐repetitive systems. This article uses a priority rule that is based on real‐time demand and production information for sequencing jobs in a kanban‐controlled flowshop. The analysis of the effect of this priority rule; the number of kanbans; the length of the withdrawal cycle; First‐Come, First‐Served (FCFS); and Shortest Processing Time (SPT) on four performance measures—customer wait time, total inventory, input stock‐point inventory, and output stock‐point inventory, shows that the use of this priority rule results in a significant reduction of customer wait time and a slight decrease in inventory.