摘要:

AbstractThe development of an information systems (IS) strategy for a mineral extraction and processing plant operated by Rio Tinto Zinc (RTZ) in South Africa is described. The participative approach used was developed from soft OR and systems thinking. The aim of the Richards Bay project was to test commercially whether the Participative Information Management Strategy (PIMS) methodology could be used as a standard method to be applied to the development of an information systems strategy at any mine site. The paper describes the implementation of the process and the problems encountered. More generally it discusses the diffusion of new ideas in an international company, illustrated by the use of the participative approach for other activities including systems development. Conclusions are drawn about the value of participative approaches based on soft OR in this context.

ISSN:0160-5682    

DOI:10.1057/jors.1996.138

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractWhile the problem of packing single containers and pallets has been thoroughly investigated very little attention has been given to the efficient packing of multiple container loads. Normally in practice a multiple container load is packed by a single container algorithm used in a greedy fashion. This paper introduces the issues involved in multiple container loading. It lays out three different strategies for solving the problem: sequential packing using a single container heuristic, pre-allocating items to the containers and choosing container loads using simultaneous packing models. The principal simultaneous models are pattern selection IP models. We present an application of packing pipes in shipping containers using two pattern selection IP models, a pattern selection heuristic, a sequential greedy algorithm and a pre-allocation method. The experimental results use randomly generated data sets. We discuss several useful insights into the methods and show that for this application the pattern selection methods perform best.

ISSN:0160-5682    

DOI:10.1057/jors.1996.139

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractThe use of cul-de-sacs and one-way streets has been proposed as a means to reduce crime in several locales. Closing streets or restricting flow patterns on them make travel through neighbourhoods more difficult and may also serve to define better the neighbourhood. Both of these effects it is hoped will reduce crime. A deleterious side-effect of cul-de-sacs is the increased difficulty of travel for all people who traverse the neighbourhood—specifically providers of essential services such as the fire department and the police department. A problem faced by city planners is where to most effectively place these impediments to travel so that they make travel difficult for the criminal, but not too difficult for residents and allow essential services to be provided expeditiously. This problem is modelled and its complexity explored, with several simplified variants studied. A prototype interactive design aid, that will enable city planners to use a computer to develop solutions, is described and its potential use is explored.

ISSN:0160-5682    

DOI:10.1057/jors.1996.140

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractAdvertising fee decisions in franchise systems are a frequent source of conflict between franchisors and franchisees. Such disagreements persist because the win-win potential of vertical cooperative advertising is not well appreciated. Our paper introduces a formal normative approach for analyzing, understanding and subsequently making these vertical cooperative advertising decisions within a franchising context in a manner that results in optimal system-wide returns. The model demonstrates that cooperative determination of franchisor's and franchisee's advertising contributions may yield superior payoffs for both exchange partners than the total payoff if the franchisor and franchisee seek to optimize their individual objective functions. Three types of models are developed and evaluated (i.e. deterministic, stochastic and under conditions of differing perceptions of the sales response functions to advertising). Conclusions hold under all three model variants. Industry implications are also presented.

ISSN:0160-5682    

DOI:10.1057/jors.1996.141

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractNegotiating and meeting due-times for work-orders is often the most important concern of managers of manufacturing systems. We propose a new approach called overtime scheduling that determines on which work-centres, when and how much overtime is required to meet a requested due-time with minimum overtime cost. This method would be used as a part of a finite-capacity real-time scheduling and planning system. We propose a work-order insertion based approach, where a new work-order is scheduled without substantially changing the schedule of previously scheduled work-orders. Based on this approach, we characterise the solution space and present experimental results on the performances of several heuristics.

ISSN:0160-5682    

DOI:10.1057/jors.1996.142

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractPracticable methods for optimising concave-cost, uncapacitated transshipment networks are non exact. In this paper, one such effective method, that of adjacent extreme point search, is further developed to enhance its overall computational efficiency. The enhanced search algorithm is then imbedded in a tabu search scheme which proved capable of finding better solutions, by a wide margin in some instances. Another tabu search scheme, somewhat inferior in terms of solution quality but computationally more efficient, is also developed to provide an alternative solution vehicle for larger networks. Results of extensive computational testing are included.

ISSN:0160-5682    

DOI:10.1057/jors.1996.143

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractThe concept of‘nested methods’is adopted to solve the location-routeing problem. Unlike the sequential and iterative approaches, in this method we treat the routeing element as a sub-problem within the larger problem of location. Efficient techniques that take into account the above concept and which use a neighbourhood structure inspired from computational geometry are presented. A simple version of tabu search is also embedded into our methods to improve the solutions further. Computational testing is carried out on five sets of problems of 400 customers with five levels of depot fixed costs, and the results obtained are encouraging.

ISSN:0160-5682    

DOI:10.1057/jors.1996.144

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractA new production-inventory model is developed for an item with increasing time-varying demand during a finite planning period. We assume that shortages are fully backordered, and the cost of adjusting the production rate depends on the magnitude of the change in the production rate. The objective is to find the optimal policy of adjusting the production rate in order to minimize the total system cost. A solution procedure is presented and a numerical example is provided for the special case of linearly increasing demand.

ISSN:0160-5682    

DOI:10.1057/jors.1996.145

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractWe study a problem of scheduling deteriorating jobs, i.e. jobs whose processing times are an increasing function of their starting times. We consider the case of a single machine and linear job-independent deterioration. The objective is to minimize the sum of weighted completion times, with weights proportional to the basic processing times. The optimal schedule is shown to beΛ-shaped, i.e. the sequence of the basic processing times has a single local maximum. Moreover, we show that the problem is solved inO(NlogN) time. In the last section we test heuristics for the case of general weights.

ISSN:0160-5682    

DOI:10.1057/jors.1996.146

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractOptimal purchasing policies are derived for a continuous review inventory system in which backlogs are permissible and temporary price discounts are available. This paper derives such policies assuming that the sale price is not available at the regularly-scheduled replenishment time. Results indicate that, under specific conditions, maximum positive cost savings are generated when a special order is placed at the end of the sale period.

ISSN:0160-5682    

DOI:10.1057/jors.1996.147

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor