ISSN:1059-1478    

DOI:10.1111/j.1937-5956.1995.tb00037.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

The mantra of health care reform in hospitals in the United States and elsewhere, the spiralling costs of health care, and the development of diagnostic‐related groups (DRGS) that define health services as “products” are influencing the strategic role of operations planning and control in hospital delivery systems. We developed a new operations planning and control system that we call “Hospital Resource Planning” (HRP). This system is based on the concept of DRGS and the familiar concept of manufacturing resources planning (MRP‐II). TO determine the potential feasibility of HRP, we gathered longitudinal data from two hospitals, one 300‐bed community hospital and one 1,100‐bed teaching hospital. Our exploratory study indicated that while the concept of MRP‐II can be transferred to hospitals, the traditional MRP logic has shortcomings. HRP advances prior research in three ways: (1) consideration of DRGS as products with a bill of resources structure that simultaneously incorporates both capacity and materials resources, (2) implementation of a hospital‐wide (versus a functional) planning and control'system, and (3) gross‐to‐net requirements logic based on notions of treatment staging. Other feasibility issues that we addressed pertain to a stochastic bill of resources, trends toward hospital product standardization, and the coordination of a central planning system with decentralized decision making. The paper concludes with a description of ar

ISSN:1059-1478    

DOI:10.1111/j.1937-5956.1995.tb00038.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

This paper describes a global job shop scheduling procedure that uses a genetic algorithm to find a good schedule. Unlike previously considered algorithms, this procedure has been implemented in the scheduling system for a manufacturing facility and has led to improved scheduling. This facility is a semiconductor test area. The test area is a job shop and has sequence‐dependent setup times at some operations. The concern of management is to meet their customer due dates and to increase throughput. This requires the coordination of many resources, a task beyond the ability of simple dispatching rules. We discuss a centralized procedure that can find a good schedule through the use of a detailed scheduling model and a genetic algorithm that searches over combinations of dispatching rules. We discuss our effort in developing a system that models the shop, creates schedules for the test area personnel, and makes a number of contributions to test area managemen

ISSN:1059-1478    

DOI:10.1111/j.1937-5956.1995.tb00039.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

This is an investigation into how optimal production rates and optimal price levels react to the introduction of an environmental tax on emissions. While, in the case of perfect competition, a linear tax has no effect, I show that in the monopolistic case the optimal production and emissions rates decrease in all instances‐without an additional smoothing effect. The desirable effect, emissions peaks being cut off, is only achieved when a progressive tax is impose

ISSN:1059-1478    

DOI:10.1111/j.1937-5956.1995.tb00040.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

The paper examines the problem of finding a sequence of a finite set of expansion projects to meet a deterministic demand projection at minimum discounted cost. As the general problem is NP‐complete, we focus on the case when the demand growth is in the exponential form, which is quite often found in applications of electric power generation, transportation, water resources and communication. We find that projects' annual costs are an effective ranking criteria for determining an optimal expansion sequence. As the annual cost for a project is a function of time or capacity level, an optimal expansion sequence can be obtained easily if dominance orders of the annual costs exist for all pairwise projects, which is likely to be the case for most practical problems. When the annual costs for the projects are in conditional order, a branch‐and‐bound algorithm has been developed to effectively reduce the searching range. Our extensive computational results show that the approach is very efficient compared with the other approaches and always solves the problem to optimum although the optimality of the approach still remains to be p

ISSN:1059-1478    

DOI:10.1111/j.1937-5956.1995.tb00041.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

This paper is an extension of Billington, who used the framework of the economic production quantity (EPQ) to model setup cost reduction. In the present paper, we use the EPQ model as a starting point to investigate the nature of setup costs and the effect of setup time reduction on the increase in available capacity. Reducing setup is vital to a company's success because a lengthy changeover of machinery is expensive: it demands long production runs to justify its cost, and these, in turn, lead to excessive inventory and to a slow response to customer needs. As in Billington, setup reduction is modeled as a function of an annual amortized investment. The paper examines the behavior of the setup time, the inventory cost, the lot size, and the freeing up of machine time in the face of a capacity constraint. A solution algorithm is provided to find setup times that minimize the sum of setup and holding cost, subject to a constraint on machine availability. The analysis sheds light on the true nature of setup cost and on the opportunity cost of not reducing setups. In the constrained optimization, the Lagrangian multiplier gives an estimate of the marginal value of adding one time unit of machine capacity, or, alternatively, of reducing one unit of setup time.

ISSN:1059-1478    

DOI:10.1111/j.1937-5956.1995.tb00042.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY