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Showing papers on "Service level published in 1986"


Journal ArticleDOI
TL;DR: A comprehensive model of a stochastic, multi-echelon inventory system that takes account of the above characteristics is developed and solutions to the constrained optimization problem are found using a branch and bound procedure.
Abstract: Multi-echelon logistic systems are essential parts of the service support function of high technology firms. The combination of technological developments and competitive pressures has led to the development of services systems with a unique set of characteristics. These characteristics include (1) low demand probabilities: (2) high cost items; (3) complex echelon structures; (4) existence of pooling mechanisms among stocking locations at the same echelon level; (5) high priority for service, which is often expressed in terms of response time service levels for product groups of items: (6) scrapping of failed parts; and (7) recycling of issued stock due to diagnostic use. This article develops a comprehensive model of a stochastic, multi-echelon inventory system that takes account of the above characteristics. Solutions to the constrained optimization problem are found using a branch and bound procedure. The results of applying this procedure to a spare parts inventory system for a computer manufacturer have led to a number of important policy conclusions.

116 citations


Journal ArticleDOI
Paul Zipkin1
TL;DR: In this article, the authors argue that standard approximations for two often-used inventory service-level measures may perform poorly in many situations and confirm the long-standing conjecture that the relatively exact formulas for these quantities are convex functions of the relevant control variables.
Abstract: We argue that standard approximations for two often-used inventory service-level measures may perform poorly in many situations. Then we confirm the long-standing conjecture that the relatively exact formulas for these quantities are convex functions of the relevant control variables. Both results suggest the exact expressions should be seriously considered in practical work.

90 citations


Journal ArticleDOI
TL;DR: In this article, the multi-dimensional effects of demand uncertainty (and other environmental characteristics) in connection with a time-phased order-point system in a rolling schedule environment were considered.
Abstract: SUMMARY This paper considers the multi-dimensional effects of demand uncertainty (and other environmental characteristics) in connection with a time-phased order-point system in a rolling schedule environment. Recorded performance variables were: the number of stockouts, the maximum stockout in a period, the service level, the inventory level and the number of orders placed. The system was observed under three conditions: no demand uncertainty, demand uncertainty present but no safety stocks and demand uncertainty present with safety stocks to counter its effects. Stockouts, larger inventories and more orders occurred simultaneously when demand uncertainty was introduced in the operating environment. Service levels were reduced and inventory levels increased when forecast errors became larger. Injection of safety stocks to counter the effect of the forecast errors further increased the inventory levels and the order frequency. The dramatic differences between environments with and without demand uncertain...

42 citations


Journal ArticleDOI
TL;DR: In this paper, the potential for customer service to contribute to a company's sales is generally acknowledged and has received considerable attention in the literature over the past several years, but little work has been done to confirm the proposed sales service relationships through analysis of historical data.
Abstract: Before distribution managers can effectively manage customer service, they must be able to determine how sales respond to various levels of service. The potential for customer service to contribute to a company's sales is generally acknowledged and has received considerable attention in the literature over the past several years. Much of the work, however, has been of a theoretical nature. Empirical studies have been confined largely to analyses of data collected by surveys which measure respondents' opinions regarding varying levels of logistics service. Hence, conclusions are based on sales expectations or purchase intentions of sellers and buyers, respectively. It is not suggested that respondents would misrepresent their concern for service levels, but little work has been done to confirm the proposed sales‐service relationships through analysis of historical data. If expectations and/or intentions indeed become actions, the impact should be observable in sales patterns over time.

11 citations


Journal ArticleDOI
TL;DR: A model that incorporates uncertainty in work load forecasts and staffing flexibility into the decision-making process and examines their interaction is presented, suggesting that increased staffing flexibility reduces the needed equipment investment, since part time staff can be scheduled more conveniently to meet varying work loads.

11 citations


Journal ArticleDOI
TL;DR: In this paper, the authors deal with service level constraints which are defined over a fiscal period and show that a confusion between a lead-time and fiscal-period perspective can result in substantial financial consequences and is therefore of managerial relevance.
Abstract: SUMMARY This paper deals with service level constraints which are defined over a fiscal period. Fiscal-period-based service level constraints are considerably more complex than their lead-time counterparts and result in significantly different safety stock requirements. Thus, a confusion between a lead-time and fiscal-period perspective can result in substantial financial consequences and is therefore of managerial relevance. Although no generalizations are possible from the limited results presented, further computational experience suggests that the findings reported hold over a wide range of situations.

6 citations


Journal ArticleDOI
TL;DR: In this article, a reformulation of the aggregate planning problem is proposed, which more closely agrees with situations frequently encountered in practice, assuming that a firm's production planners want to determine the expected service and inventory levels for a given production profile in the face of uncertain seasonal demand.

5 citations


01 May 1986
TL;DR: In this paper, the authors discuss Chinese management, labor productivity, quality of industrial and consumer products, costumer service level, and worker motivation, and conclude that worker motivation is important.
Abstract: This report discusses Chinese management, labor productivity, quality of industrial and consumer products, costumer service level, and worker motivation.

5 citations


Journal ArticleDOI
TL;DR: Results show that for the range of service level considered in this paper, the model developed provides close approximations to the optimal values of s and S for wide ranges of demand and cost parameters.
Abstract: In this paper, a simple regression model is developed for the estimation of optimal inventory-control parameters for items with lumpy demand patterns when a service level is specified. The control discipline is the (s, S) policy with continuous review. The lead time is assumed to be known and constant, and there is assumed lo be complete backlogging of unfilled demand. A lead-time demand distribution of stuttering Poisson nature is assumed. Customer service is defined as the probability of having a non-negative net inventory at an arbitrary time. A grid of 2688 known optimal policies is used to provide data for calibration of the regression model. Extensive computational results show that for the range of service level considered in this paper, the model developed provides close approximations to the optimal values of s and S for wide ranges of demand and cost parameters

1 citations


01 Jan 1986

1 citations