1) Force Effectiveness Assessment, Kah Wah Lai / Ministry of Defence, Singapore, Cdso, Mindef Bldg, Gombak Dr, Singapore, 2366, Singapore, Kim Pong Ong / Ministry of Defence, Singapore, G5-Army, Mindef Bldg, Gombak Dr, Singapore, 2366, Singapore This paper outlines the approach used to help assess the operational effectiveness of given fire support force structure options. An area weapon model was first used to generate expected damages for each firing unit - target type combination. These weapon effectiveness results are then fed into a series of linked spreadsheets which trace the phases of the fire support plans. The proportions of missions fulfilled indicates the temporal adequacy of various force structure options. The utilisation/idleness rates revealed opportunities for improving fire support allocation.
2) An Analytical Approach to Assessing Lethality of Area Weapons in Salvo Attack, Gim Koon Yeo / D S O - Mindef, 20 Science Park Dr, Singapore, 0511, Singapore This paper presents a simple modelling technique that can be readily employed for assessing the lethality of area weapons in a salvo attack. The measure of effectiveness is the expected damage to the area target after a salvo attack. To illustrate the use of the technique, analytical models for several scenarios such as attack against hard targets requiring multiple hits on the same spot, attack against targets with arbitrary damage contour, attack using multiple aim-points with arbitrary hit distribution and smart weapon attack are derived.
3) Analysis Support Environment, Bok Chan / Axon Research, Tanglin, P O Box 0398, Singapore 9124, Singapore, Cheng Hwee Sim / Ministry of Defense, Gombak Dr, Singapore 2366, Singapore A computerized system was developed to help analysts carry out OR projects. It was built based upon a visual object-oriented idea processor. OR-related information is encapsulated as visual templates and checklists. Models can be documented and executed from within the environment.
4) Strategic Airlift Assets Optimization Model, Teo Weng Lim / Rep of Singapore Air Force, H Q R S A F O A Branch, Gombak Dr, Singapore, SE 2366, Singapore, David Morton / Naval Postgrad Sch, O R Dept, N P S, Monterey, CA 93942, USA, Richard E. Rosenthal / Naval Postgrad Sch, O R Dept, N P S, Monterey, CA 93943, USA A GAMS optimization model helps US Air Force improve logistical efficiency. It maximizes on-time cargo and passenger throughput for a given air fleet over a given network, subject to physical and policy constraints. The model helps answer questions about selecting airlift assets and about investing or divesting in airfield infrastructure.
1) Property and Stock Prices in Hong Kong, Yuming Fu / City Polytechnic of Hong Kong, Dept of Econ & Fin, Hong Kong Property prices in Hong Kong are among the highest in the world and are very volatile. This paper examines the determinants of property prices and the interactions between the property markets and the stock price market in Hong Kong.
2) Distribution of Golf Course Prices in Japan, Zari Rachev / Univ of California, Dept of Stats, Santa Barbara, CA 93106, USA, W.T. Ziemba / Univ of Brit Columbia, Fac of Commerce, 2053 Main Mall, Vancouver B C, Canada V6T 1Y8 Golf course membership prices in Japan form a $250 billion plus market. They provide good data on speculative land prices because weekly transaction data in various areas are available from January 1982 to the present. We consider the distribution of these prices and also the Nikkei and Topix stock averages. Key questions considered are: was ther a speculative bubble in any or all of these prices in the late 1980's; what are the properties and form of univariate and multivariate models of these prices; and how do the latter compare with US asset prices.
3) Land and Stock Prices in Japan, Douglas Stone / Nicholas Applegate, Global Res Dept, 600 W Broadway, 29th Floor, San Diego, CA 92101, USA, W.T. Ziemba / Univ of Brit Columbia, Fac of Commerce, 2053 Main Mall, Vancouver B C, Canada V6T 1Y8 We consider the relationship between land and stock prices in Japan from 1955 to 1994. This is analyzed in terms of price changes, lead and lag relationships and econometric predictive models. Both essential use (housing, industrial, etc.) and speculative land (measured by golf course membership prices) is considered. The time path of land and stock price rises and declines is studied throughout the study period with particular focus on the large rise in the late 1980's and fall in the early 1990's.
1) Dynamic Flight Scheduling System, Andrew Lim / Information Technology Inst, 71 Science Park Dr, Singapore 0511, Singapore In this paper, we shall present an online dynamic flight scheduling system that will dynamically assign flights to planes satisfying various constraints. In the event that no feasible assignment is found, the system will propose good alternatives.
2) A Decision Support Framework for Fleet Routing and Flight Scheduling, Shangyao Yan / Nat'l Central Univ, Dept of Civil Eng., Chungli, Taiwan ROC, Hwei-Fwa Young / Nat'l Central Univ, Dept of Civil Eng., Chungli, Taiwan ROC This research develops several multiple time-space network models to help carriers adjust draft timetables and fleet routes when market demand conditions are changed. These models are formulated as multiple commodity network flow problems. Solution algorithms are suggested. A case study regarding operations of a major Taiwan airline is presented.
3) Constraint-based Gate Allocation and Reallocation, Rainer Berger / Knowledge Eng Ptc Ltd, Changi Airport, P O Box 8001, Singapore 9181, Singapore We have developed a constraint-based gate and belt allocation system for airports that performs reallocation in real-time as changes in flight information and resource availabilities are received. The system uses object-oriented AI search and optimization techniques to find the most preferred solution while keeping last-minute changes to a minimum.
4) Optimal Booking Policy for Multi-Segment Flights, Marvin Hersh / Florida Atlantic Univ, Dept Decision & Info Systems, Boca Raton, FL 33431-0991, USA, Tak C. Lee / Nat'l Univ of Malaysia, Fac of Bus Mgt, Bangi, Selagor, Malaysia A model is presented for controlling the seat inventory in multi-segment flights. An analysis using Dynamic Programming shows that the optimal policy can be simplified to certain critical values which can be used to control the reservation process while significantly reducing the computational time for solving the problem.
1) Design of Survivable International Telecommunication Networks, G Anandalingam / Univ of Pennsylvania, Dept of Systems Eng, Towne Bldg, Philadelphia, PA 19104 6315, USA, Keesung Nam / Univ of Penn, Dept of Systems Eng, Philadelphia, PA 19104-6315, USA The problem of designing survivable international telecommunication networks is solved to near optimality using simple heuristics. A minimum cost survivable network is obtained first, then capacity assignment and routing problems are solved under normal and link failure conditions. Numerical results and sensitivity analysis are reported for the Pacific Basin network.
2) Optimal Interconnection of L A Ns Using Spanning-Tree Routing Bridges, June S. Park / Univ of Iowa, Dept of Mgt Science, Iowa City, IA 52242-1000, USA, Fred Kaefer / Univ of Iowa, Dept of Mgt Sciences, Iowa City, IA 52242-1000, USA An I P model is constructed with finds a minimal-cost interconnection of L A Ns using I E E E 802.1 bridges. The model prevents congestion even in a L A N or bridge failure. A tabu search alsgorithm to determine protocol parameters is presented. Tight Lagrangian bounds are obtained based on the parsimonious property of biconnected networks.
3) Survivable Network Design in Connection with S D H Networks, Geir Dahl / Univ of Oslo, Inst of Info, Gaustadalleen 23, P O Box 1080 Blindern, Oslo, 0316, Norway, Mechthild Stoer / Norwegian Telcom Research, Instituttveien 23, P O Box 83, Kjeller, N-2007, Norway We consider some optimization problems arising in the design of survivable telecom networks based on the new S D H transmission technology. Models and methods for finding cost-effective networks with suitable ring structure are presented. Furthermore some preliminary conputational results based on realistic data are given.
4) Designing and Planning Wide Area Private Networks, Heung Sik Choi / Univ of ROChester, W E Simon Grad Sch of Bus Adm, Rochester, NY 14627, USA This paper studies reconfigurable private digital networks that employ Digital Crossconnect Systems using T1 and T3 circuits. The link capacity decision (a long-run problem) and a crossconnect scheme (a short-run problem) are combined to exploit economies of scale. Numerical examples and experiments support the importance of integrated planning.
1) Logic Programming with Pseudo-Boolean Constraints, Alexander Bockmayr / Max - Planck Inst For Infor, I M Stadtwald, D-66123 Saarbrucken, Germany We survey recent work on the constraint logic programming language CLP(PB) for logic programming with pseudo-Boolean constrains, which combine Boolean algebra with arithmetic and are closely related to 0-1 integer programming. We give some typical applications in operations research and artificial intelligence. Then we present cutting plane techniques for the solution of linear pseudo-Boolean constraints.
2) Tight Representation of Logical Constraints, Hong Yan / Carnegie Mellon Univ, GSIA, Pittsburgh, PA 15213, USA, John Hooker / Carnegie Mellon Univ, GSIA, Pittsburgh, PA 15213, USA Suppose one wants to incorporate loginal rules or constraints into a mathematical programming model. We derive the tightest possible (i.e., convex hull) representation of one class of logical constraints, namely cardinality rules. These say that if at least K of A, B, C, etc. are true, then at least L of P, Q, R, etc. are true.
3) Constraint Logic Programming and Its Application to Scheduling Problems, Mehmet Dincbas / Parc Club Orsay Univ, Cosytec, 4 Rue Jean Rostand, Orsay Cedex, 91893, France Constraint Logic Programming is a new emerging and very promising technology that appeared at the end of the 80's. It tends to generalise conventional Logic Programming (examplified by Prolog) by introducing, besides basic logical inference mechanisms, more mathematical and algorithmic techniques. It is especially well suited for solving complex "constraint search problems" where there are several types of constraints. Typical current application areas of CLP are production scheduling, project management, and crew assignment.
4) Logic and LP-Based Design of Truss Structures, John Hooker / Carnegie Mellon Univ, GSIA, Pittsburgh, PA 15213, USA, Srinivas Bollapragada / Carnegie Mellon Univ, GSIA, Pittsburgh, PA 15213, USA, O. Ghattas / Carnegie Mellon Univ, Mechanical Engineering Dept, Pittsburgh, PA 15213, USA We compute optimal design of truss structures by combining logic-based and LP-based methods. We use logic processing to control the enumeration of linear relaxations of the problem. We also derive cuts in the form of logical propositions to prune the search tree. The cuts are stronger than valid cuts but do not exclude the optimal solution.
1) Internet-Protocol Connectivity in Russia, Eastern Europe, and Central Asia: Opportunities and Obstacles, Anatoly Voronov / Glasnet, Sadovaya Chernogriazskaya Ul 4, Moscow, 107078, Russia, Tony Byrne / Int'L Res & Exchange & Board, 1616 H St, N. W., Washington, DC 20006, USA, Bill Fick / Int'L Res & Exchange Board, 1616 H St N. W., Washington, DC 20006, USA, Raymond Viers / P E R D C A, Project On Econ Reform & Devel, Furkat St.1, Room #609, Tashkent, 27, Uzekistan, Stan Brunn / Univ of Kentucky, Dept of Geography, Lexington, KY 40506-0025, USA The panel presents a status report on enhanced Internet Protocol connectivity options in geographic regions where communications have been problematic. Representatives of GlasNet in Moscow, IREXNet in Washington, and SilkNet in Central Asia will profile regional linkage developments. Discussion of the geography of information provides a synthesizing view of developments.
1) IT Security and Control in International Hotels, Ann Nguyen / Griffith Univ, Fac of Eng & Appl Sci, Pmb 50, Gold Coast Mall Cntr, Qld 4217, Australia, John Van Rooy / Griffith Univ, Fac of Eng & Appl Sci, Pmb 50, Gold Coast Mall Cntr, Qld 4217, Australia, Richard Carey / Griffith Univ, Fac of Eng & Appl Sci, Pmb 50, Gold Coast Mall Cntr, Qld 4217, Australia Tourism is one of the fastest growing industries in the Asia-Pacific region. This paper examines current information technology (IT) security and control practices in major international hotels in Queensland, Australia. The investigation covers key aspects of security and control, including the physical security of the equipment, access controls, backup procedures, remedial and preventative maintenance, contingency planning, and software and data integrity. The paper also includes recommendations for improvement.
2) Success Factors for Implementation of Executive Information Systems, Gregory K. Whymark / Central Queensland Univ, Faculty of Business, ROCkhampton Qld 4702, Australia, A. Srivihok / Central Queensland Univ, Faculty of Bus, ROCkhampton Qld 4702, Australia This paper describes a theoretical framework for EIS development, and uses it to analyse two case studies, one a failure and one a success. The two projects are compared and with the assistance of the theoretical framework, a number of the success factors identified. Further research required is also addressed.
3) Rapid Application Development Using Screenflow Engineering, John Paynter / Univ of Auckland, Private Bag 92019, Auckland, New Zealand The Screenflow systems development methodology provides an efficient and effective means of creating application based in such a shared relational database environment. This paper describes the methods used to develop a corporate information system at Goodman Fielder Wattie (NZ) Ltd.
1) A Workbench to Support the Evaluation of IS/IT Investment, Vasilis Serafeimidis / London Sch of Econ & Poli Sci, Info Sys Dept, Houghton St, London Wc2A 2Ae, Great Britain, Steve Smithson / London Sch of Econ & Poli Sci, Info Sys Dept, Houghton St, London Wc2A 2Ae, Great Britain In this presentation the evaluation of Information Systems is approached as an important and complex process which involves many groups of stakeholders. It discusses a conceptual model in order to provide a foundation to approach evaluation as a group decision making process. The framework is used to elicit the user requirements and the design the modules of the workbench. A case study of the development of a prototype of it is also presented.
2) The Use of the Grouputer in Preparing Information Management Plans, Edward Lewis / Univ of New South Wales, Dept of Comp Sci, Australian Defence Force Acad, Canberra, Australia, Charles Newton / Univ of New South Wales, Dept of Comp Sci, Australian Defence Force Acad, Canberra, Australia The presentation addresses our experiences in using the Grouputer GDSS to develop the Information Management plans of various agencies in Australia and in the Philippines. The Grouputer is a facility designed in Australia that allows 12 participants to share ideas and judgements at the same time and place. We have used the facility extensively to produce vision statements, user requirements, and policy decisions for the use of information systems. The presentation discusses the lessons that we have learned and the suggestions that we have for designing GDSS for Information Management planning.
3) G(D)SS as Support for Designing Organizations and Information Systems-Concluding Discussion: Where Do We Go from Here?, Gert-Jan De Vreede / Delft Univ of Tech, Sch of Sys Eng, Policy Analysis, And Mgt, Jaffalaan 5, 2600 Ga, The Netherlands, Gary W. Dickson / North Carolina State Univ, Dept of Bus Mgt, Box 7229, Raleigh, NC 27695-7229, USA, Henk G. Sol / Delft Univ of Tech, Sch of Sys Eng, P O L Analysis, & Mgt, Jaffalaan 5, Delft 2600 G A, Netherlands The role G(D)SS as support for designing organizations and information systems is discussed in four sessions: GDSS and Integrated Aprroaches to IS and Organization Design, GDSS as Support for Organization Development, and GDSS as Support for Information Systems Design (Part I and II). The main themes of these sessions are summarized while highlighting salient features. Opportunities for further research are identified. The floor is opened for discussion, and the sessions' participants are encouraged to comment on the issues raised during the presentations.
1) Hydrodynamic Limit of Feedback Queues in Series, Raj Srinivasan / Univ of Saskatchewan, Dept of Math & Statistics, Saskatoon, Sk S7N 0W0, Canada We study a large serial network with feedback via some simple models of interating particle systems. This approach provides valuable insights into how these networks approach equilibrium. Using a simple exclusion process, we derive the so called 'hydrodynamic limit' of this network.
2) Stochastic Representation of Pick-and-sort Systems, Gunter P Sharp / Georgia Inst of Tech, Sch Indst/Sys Eng-Logstcs Inst, 765 Ferst Dr, Atlanta, GA 30332-0205, USA, Kyung-Il Choe / Samsung Data Sys Co. Ltd., 219-1, Migun-Dong,Seodaemun-Gu, Imkwang Bldg, Seoul 120-020, Korea, Richard F. Serfozo / Georgia Tech, ISYE, 765 Ferst Dr, Atlanta, GA 30332-0205, USA A pick-and-sort (PAS) system for order picking consists of an aisle-based pick system (PS) and a conveyor loop accumlation and sorting system (A/SS). The PAS is formulated as a 2-stage tandem queue. Analytical results are compared to those from simulation.
3) An Approximation Procedure for Semaphore Queueing Systems, Paul Luh / Natinal Chengchi Univ, Dept of Mathematical Sciences, Taipei, Twiwain ROC We present a control mechanism for analyzing open queueing networks. This queueing model can be used for performance evaluation of a processing system of simultaneous resource possession which arises in a multiple programming situation. The approximated congestion measures of such a system are analyzed and calculated.
4) A Noval Approach for Analyzing Vacation Queues with General Input Process We introduce a new approach for modeling and analyzing vacation queueing systems. We assume that uncertainty can exist in the customer's arrival process, service time, and server's vacation time. Our analysis provides explicit expressions for the mean and variance of the cycle time and the average customer waiting time.
5) Traffic Intensity Estimation in M/M/1 Queues with Covariates, So Young Sohn / Naval Postgraduate School, Dept of Operations Research, Code Or/Sh, Monterey, CA 93943, USA, Chul Sohn / Korea Local Admin Institute, Seoul, Korea In this paper, we consider a set of individual M/M/1 queues in which variations in both arrival rates and service rates are partly explained by some covariates representing associated characteristics of individual queues. The random error that takes into account the remaining variation is assumed to follow either a gamma or a lognormal distribution. Several methods for estimating the traffic intensity parameter are suggested and their performances are compared.
1) A Framework to Examine Inventories for Supply Chain Management, G. Raghuram / Indian Inst of Mgt, Public Systems Group, Vastrapur, Ahmedabad, 380 015, India This paper examines the nature of inventories in the supply chain to help analyse what desirable inventory levels should be and how to go about reducing the excess inventories. Inventories can be classified as being due to size requirements (shipment, order quantity, batching), pipeline (transportation, work in process), buffer stocking (to cover uncertainties in lead time and demand), and mix requirements (order processing prior to manufacture and prior to despatch).
2) Simultaneous Reduction on Setup Cost and Lead Time Variability, Xin Xin He / South Carolina State Univ, Dept of Bus Admin, Sch of Bus, Orangeburg, SC 29117, USA Using the concept of pseudo-setup cost with stochastic lead time inventory models, we analyze setup cost and lead time reduction simultaneously with a closed-form expression. Consequently, the result of this research provides an important mechanism for integrating the studies on setup cost reduction and lead time variability reduction.
3) Inventory and Disposal Policies in Response to a Sale, K. Jo Min / Iowa State Univ, 205 Engineering Annex, Isu, Ames, IA 50011, USA We study inventory and disposal policies in response to a sale. Disposal can be a valuable managerial tool (e.g. due to holding cost advantages). The total cost saving is maximized over various inventory and disposal policies, and the optimal objective value and decision variables are analyzed for managerial insights.
4) A Survey of Quantity Discount Inventory Models, Omprakash K. Gupta / Indiana Univ Northwest, Div of Bus & Econ, 3400 Broadway, Gary, IN 46408, USA In this paper, we survey inventory models dealing with quantity discount. In addition to reviewing the literature, the survey will identify gaps and suggest potential research areas.
5) Deterministic Inventory Models with Linearly Increasing Demand and Random Lead Time, Shailesh Bhavsar / Not Available.
1) Green Manufacturing, Soheila Jorjani / Cal State Univ - S M, College of Bus, San Marcos, CA 92096-0001, USA, Jack Leu / Cal State Univ - S M, College of Bus, San Marcos, CA 92096-0001, USA, Sheldon Lou / Cal State Univ - S M, College of Bus Admin, San Marcos, CA 92096 0001, USA, George Diehr / Cal State Univ - S M, Coll of Bus, San Marcos, CA 92096-0001, USA Green Manufacturing in a global market is one of the newest challenges facing the "environmentally conscious" manufacturing organizations. This paper surveys the practices of these organizations as well as the environmental regulations in U.S. and European countries. In addition, issues related to product design and reverse distribution in the content of green manufacturing will be discussed.
2) Perspectives on Process Improvement in Manufacturing Systems, Paul Iyogun / Wilfrid Laurier Univ, School of Busi & Econ, Waterloo Ontario, Canada N2L 3C5 The purpose of this research is to identify common features of programs for process improvement in manufacturing. Programs such as TQM, continuous improvement, process re-engineering, agile manufacturing, etc., have been proposed. The potential impact of each of these on an organization will be discussed.
3) An Integrated Model for Dynamic Production Scheduling, Jiyin Liu / Hong Kong Univ of Sci & Tech, Dept of Ind Eng, Clear Water Bay, Kowloon, Hong Kong Production scheduling is a crucial function in production and operations management. This paper identifies and ephasizes two main characteristics of practical scheduling problems, dynamic nature and the need for overall optimization. Two types of previous scheduling approaches are then reviewed and discussed. A conceptual model from a control theory perspective is then presented as a framework for integrated dynamic scheduling problem. The controller of the model is described and discussed. The relationship between the new approach and the previous scheduling approaches is also discussed.
4) On Measures of Flexibility, Swaminathan Sankaran / Univ of Regina, Fac of Admin, Regina, Sk, Canada S4S 0A2 Flexible Manufacturing Systems or F M S are finding increasing favour in advanced economies under current economic conditions. However, there are different kinds and levels of flexibility to be used either as benchmarks or as goals. There are no uniform guidelines for applying or measuring these notions of flexibility. This paper attempts a critical evaluation of proposed measures of flexibility.
1) One-Machine Batching and Sequencing of Multiple-Type Items, Edwin Cheng / Hong Kong Polytechnic, Fac of Business & Info Sys., Hung Hum, Hong Kong, Z.L. Chen / Princeton Univ, Dept of Civil Engg & Oper Res, USA, Ceyda Oguz / Hong Kong Polytechnic, Department of Management, Hung Hom Kowloon, Hong Kong We consider a single-machine batch scheduling problem with setup times to minimize the total job flowtime. There are N jobs of T different types. Only jobs of the same type can be batched. We present a dynamic programming algorithm to solve this problem.
2) A Layered Matching Heuirstics for the Manufacturing Machine Design Problem, Merza H. Hasan / Kuwait Univ, College of Commerce, P O Box 5486, Safat, 13055, Kuwait, Abdul-Kareem Al-Saffar / Kuwait Univ, Colleg of Commerce, P O Box 5486, Safat, 13055, Kuwait The paper is concerned with the development of a heuristic algorithm based on layered matching (K matching) to maximize a weighted sum of adjacent activities. The K-matching model is formulated as maximal player graph problem. The solution quality and computational time generated from the proposed procedure compared with the other algorithm is good.
3) On the Fixed Interval Due-Date Scheduling Problem, Chung-Lun Li / Washington Univ, John M Olin Sch of Business, Campus Box 1133, St Louis, MO 63130, USA, Chung-Yee Lee / Univ of Florida, Dept of Ind And Sys Eng, 303 Weil Hall, Gainesville, FL 32611, USA Given a set of jobs, "fixed interval due dates" are assigned and jobs are scheduled so that the total due date cost plus the total earliness is minimized and each job must be finished at or before its due date. Computational complexity and worst-case analysis of this problem are discussed.
4) Determination of Common Due Window Location in a Single Machine Scheduling Problem, Surya D. Liman / Texas Tech Univ, Dept of Ind Eng, Lubbock, TX 79409-3061, USA, Shrikant S. Panwalkar / Lonestar Co, Pune, India, Sansern Thongmee / Texas Tech Univ, Dept of Ind Eng, Lubbock, TX 79409-3061, USA We consider a single machine scheduling problem in which n jobs have a common due window. Jobs that are completed within the window incur no penalty. The objective is to find the optimal sequence and the optimal common due window location based on a given due window size such that the total earliness, tardiness, and common due window location penalties are minimized.
5) Fast Parametric Scheduling Algorithms, S. Thomas Mccormick / Univ of Brit Columbia, Fac of Commerce, Vancouver, BC, Canada V6T 1Z2 Y.L. Chen gave polynomial algorithms for two variations of a scheduling problem where the processing times can be shortened at a cost. This paper shows how parametric network flow techniques lead to much faster algorithms for both of Chen's problems. We also consider some extensions of Chen's model.
1) Determinants of Successful New Product Developments in Australia, Larry Dwyer / Univ of Western Sydney, Centre For Mgmt & Leadership, P.O. Box 555, Campbelltown, Nsw 2560, Australia, Robert Mellor / Univ of Western Sydney, Centre For Mgmt & Leadership, P.O. Box 555, Campbelltown, Nsw 2560, Australia, Stewart Clegg / Univ of Western Sydney, Centre For Mgmt & Leadership, P.O. Box 555, Campbelltown, Nsw 2560, Australia, Sharon Kemp / Univ of Western Sydney, Centre For Mgmt & Leadership, P.O. Box 555, Campbelltown, Nsw 2560, Australia Results from a study of new product developments in Australian biotech, pharmaceutical, telecommunication and electronics firms are reported. Critical success/failure factors are identified and links are made between culture, sub-culture and orgainzational performance for new product success.
2) Cross Cultural Study of New Product Development Methods in Small Organisations - New Zealand vs US, D.H. Buisson / Univ of Otago, Dept of Marketing, P.O. Box 56, Dunedin, New Zealand, T.C. Garrett / Univ of Otago, Dept of Mktg, P.O. Box 56, Dunedin, New Zealand, William E Souder / Univ of Alabama-Huntsville, Cmost, Ste 126 Asb, Huntsville, AL 35899, USA The management of innovations varies in different national environments. We address the results of comparative study between New Zealand small to medium sized companies with small U.S. companies. Critical success and failure factors will be discussed with significant differences highlighted (part of the UAH 16 country INTERPROD study).
3) Comparison of US and Singapore New Product Innovation Management, Chee-Meng Yap / Nat'l Univ of Singapore, Dept of Indu & Sys Engineering, Singapore, 0511, Singapore, William E Souder / Univ of Alabama-Huntsville, Cmost, Ste 126 Asb, Huntsville, AL 35899, USA The new product development issues and success/fail factors in Singapore and the U.S. are remarkably similar as well as different. This paper will discuss the lessons learned from this comparison, and the implications for new product managers in the two cultures.
4) Time-to-Market Strategies Across Linked Industries: The Case of U.S. Semiconductor Manufacturing, Steven Brown / Sematech/Motorola, 2706 Montopolis Dr., Austin, TX 78741-6499, USA, Donald A. Hicks / Univ of Texas-Dallas, 5718 Buffridge Trail, Dallas, TX 75252, USA, Jennifer Robinson / Sematech, 2706 Montopolis Dr, Austin, TX 78741-6499, USA This paper describes the results of a benchmarking effort to identify information and insights about the time-to-market concept, its development, and application. Published resources, agencies, professional societies, and universities were appraised to determine applicability of this external knowledge base in defining appropriate metrics for the semiconductor industry.
1) Nonlinear Advertising Capital Model, Irma Luhta / Univ of Vaasa, P.O. Box 700, Vaasa, Fin-65101, Finland In this paper a time delayed feedback system between advertising and goodwill is developed on the basis of the classical Nerlove-Arrow advertising capital model. A continuous advertising function and three different effects of advertising on the dynamics of goodwill are used. The conditions in relation to the stabiltiy of the limit point of the system are also clarified.
2) Inferring Ad Effectiveness from Recognition Tests, Anil Gaba / I N S E A D, Boulevard de Constance, Fontainebleau Cedex, 77305, France, Niraj Dawar / I N S E A D, Boulevard de Constance, Fontainebleau Cedex, 77305, France Recognition tests are widely used to measure effectiveness of advertisements. However, much controversy surrounds such measures. The primary criticism is that such measures do not account for response bias, which can be considerable. We propose a framework which accounts for such response bias while estimating recognition of a particular ad.
3) Affective Attitude Towards Advertisement and Its Relationship to Acculturation and Behavioral Intention to Buy, Durriya Z. Khairullah / St. Bonaventure Univ, 2316 Sheldon Dr, Allegany, NY 14706-9440, USA, Zahid Khairullah / St. Bonaventure Univ, 2316 Sheldon Dr, Allegany, NY 14706-9440, USA The study investigates whether the Asian-Indian immigrants' affective attitudes towards American and Indian origin print advertisements vary within and across stages of acculturation. The relationships between acculturation, affective attitudes towards advertisements and behavioral intention to buy the advertised products are examined.
4) Predicting the Annual Sales of RAC in Korea Using Growth-Cycle Decomposition Diffusion Model, Young Jin Joo / Kaist, Dept of Mgmt Sci, 373-1 Kusong-Dong Yusong-Gu, Taejon, 305-701, Korea, Duk Bin Jun / Kaist, Dept of Mgmt Sci, 373-1 Kusong-Dong Yusong-Gu, Taejon, 305-701, Korea, Myoung Hwan Park / Hansung Univ, Dept of Ind Engr, 389 Samsun-Dong 2 Ga, Sungbuk-Gu, Seoul, 136-792, Korea We develop the growth-cycle decomposition diffusion model to distinguish the S-shaped growth from the short-run fluctuations caused by changes in the external environment. The proposed model is applied to the diffusion of the room air conditioners in Korea where the usual application of Bass model cannot explain the transient sales fluctuations due to unusually high temperatures.
5) Advertising Pulsing Policies and the Impact of Manufacturing Costs, Srinath Gopalakrishna / Penn State Univ, Dept of Marketing, University Park, PA 16802, USA, Richard J. Steinberg / Gte Laboratories, 40 Sylvan Rd, Waltham, MA 02254, USA Previous studies have shown the superiority of advertising pulsing over constant spending. However, the pulsing issue has been treated in isolation. The close linkages between marketing and manufacturing have been ignored. We consider production costs and report conditions under which advertising pulsing may or may not be superior to a policy of constant spending.
1) Variation of Efficiency in the Stochastic DEA, Hiroshi Morita / Kobe Univ, Dept of Comp & Sys Eng, Rokkodai, Nada, Kobe, 657, Japan We consider the stochastic DEA when the inputs and outputs are observed including random noise. In this case, the deterministic model may bring an incorrect evaluation. The stability of efficient unit and optimal weights against the stochastic variations are discussed.
2) Evaluation of Asia-Pacific Service Economies Using DEA, Tomofumi Sumita / Univ of Electro-Comm, 1-5-1 Chofugaoka, Chofu, Tokyo 182, Japan This paper evaluates efficiency of the service economies in Asia-Pacific area. To carry out the theme, Data Envelopment Analysis (DEA) is employed. In parallel with DEA, a new comprehensive indicator will be introduced to evaluate various types of economics models in a lump.
3) An Observation on the Cone-Ratio Model in DEA, Kaoru Tone / Saitama Univ, Grad School of Policy Science, Urawa, Saitama, 338, Japan Usually, there exists ambiguity in the virtual multipliers in the polyhedral cone-ratio method when some exemplary efficient DMU's multipliers are employed as the admissible directions of the cone. We will show three practical methods for resolving this ambiguity along with an example.
1) Analysis of a Cutting Plane Method That Uses Weighted Analytic Center and Multiple Cuts, Zhi-Quan Luo / Mc Master Univ, Dept Ece, Hamilton Ontario, Canada L8S 4K1 We consider the analytic center cutting plane or column generation algorithm for solving general convex problems defined by a separation oracle. The oracle is called at an approximate analytic center of a polytope, which contains a solution set and is given by the intersection of the linear inequalities previously generated from the oracle. We consider using approximate weighted analytic centers in the cutting plane method, and show that the method, with multiple cuts added in each step, has an improved complexity.
2) Declarative Systems and Integer Programming, P. Davison / Citri, 723 Swanston St, Carlton, Vic, 3052, Australia Concise, declarative systems are more flexible to an evolving and dynamic problem environment. We provide a description of an architecture for developing mathematical programming systems which uses an interpretation of algorithms as problem generation and solution intercommunication procedures. The design and implementation of a state-of-the-art mixed integer programming algorithm within the framework is presented.
3) Distributed Solution of Stochastic Programs with Restricted Sources, Stavros A. Zenios / Univ of Penn, Wharton Sch - Oper & Info Mgt, Philadelphia, PA 19104, USA, Hercules Vladimirou / Dept of Public And Business Ad, University of Cyprus, 75 Kallipoleos St PO Box 537, Nicosia 141,00500, Cyprus
1) Nurse Scheduling in Singapore: A Proposed Optimizing System, Robert A. Straughan / Nec Singapore Pte Ltd, No 1 Maritime Square #12-10, World Trade Centre, Singapore, 0409, Singapore, Paulin Tay Straughan / Nat'l Univ of Singapore, Dept of Sociology, 10 Kent Ridge Crescent, Singapore, 0511, Singapore The scheduling of nurses in Singapore is done manually. This paper proposes a computerized scheduling system that optimizes on the schedule preferences of individual nurses. The proposed system would decrease the time required to generate schedules and increase the quality of schedules. Improved schedules would aid in staff retention.
2) Optimization Models & Strategy for Driver Rescheduling in Public Transport, Kenneth Darby-Dowman / Brunel Univ, Dept of Math And Statistics, Uxbridge U B 8 3 P H, U K, James Little / Brunel Univ, Uxbridge Ub8 3Ph, Uk, Shirley Moody / Brunel Univ, Uxbridge Ub8 3Ph, Uk Rescheduling in terms of amending an existing schedule to reflect changed requirements is an important issue in sectors as diverse as manufacturing and public transport. This paper discusses practical issues and reports computational experience with optimization models applied to real problems arising in driver rescheduling in public transport.
3) AMX: The Adaptive Multi-crossing-site Crossover and its Applications to Combinatorial Optimization, Lei Zhang / Natl Natural Sci Foundation, Dept of Info Science, Beijing, 100083, China The permutation-based representation is a nonbinary genetic coding technique that is important, popular, and widely used in searching a feasible and efficient solution of such an NP-hard combinatorial optimization problem as the traveling salesman problem, flow-shop problem, etc. The partially-mapped crossover operator PMX is the most famous permutation operator. This paper presents a new crossover operator, the adaptive multi-crossing-site crossover (AMX) which can overcome drawbacks of PMX and be easily implemented.
4) Effectiveness of Evoutionary Searches in Robust Design, Tapan Bagchi / Univ of Toronto, Dept of Ind Eng, 4 Taddle Creek Rd, Toronto, Ontario, M5S 1A4, Canada, Krishan Raman / Univ of Toronto, Dept of Ind Eng, 4 Taddle Creek Rd, Toronto, Ontario, M5S 1A4, Canada, J. G. C. Templeton / Univ of Toronto, Dept of Ind Eng, 4 Taddle Creek Rd, Toronto, Ontario, M5S 1A4, Canada This paper presents an exposition of genetic algorithmic approaches to seeking robust designs. The general multiple objective robust design problem is re-formulated as a constrained optimization problem. Pilot tests are conducted to obtain optimum GA search parameters, which appear problem specific. The search is completed with appropriate penalty-augmented recursion. Five earlier-solved Taguchi-type solutions are revisited. The approach produces final designs as good as or better than those given in the recent literature. Computational aspects are extensively discussed.
5) Profit Maximization In a Constrained Production Environment., Gerhard Plenert / Byu - Ibm, 660 Tnrb, Provo, UT 84602, USA A mathematical model that combines profit maximization and cost minimization will be presented. It was developed using geometric programming.
1) R & D Management Challenges In a Changing Environment, Ashok K. Gupta / Ohio Univ, College of Bus, Athens, OH 45701, USA, David Wilemon / Syracuse Univ, Innovation Mgt Program, Sch of Mgt, Syracuse, NY 13244, USA In this article we present the major changes that have occurred in the managment of R&D during the last 5-7 years, and the anticipated changes. Then, we discuss the factors that have caused these changes to occur. Lastly, we present the importance of certain skills and knowledge domains needed to manage R&D effectively and the capability the R&D groups exhibit in each area.
2) Managing Interorganizational R & D Projects, Pepin Cabo / Univ of Groningen, Sch of Mgmt & Organization, P O Box 800, Groningen 9700 Av, The Netherlands The collaboration of different types of organizations (companies, universities, and research institutes) from different nationalities in an R & D project poses specific management problems. It appears that in the startup and feasibility phase, these problems especially concern consensus on the involvement of participants, objectives and methods of R & D. This is shown by a comparative analysis of various cases.
3) R & D Decisions, Firm Size and Market Structure, Robert W. Vossen / Univ of Groningen, School of Mgt & Org, P O Box 800, Groningen 9700 Av, The Netherlands This paper discusses the empirical performance of a model of R & D as a function of firm size, in which a distinction is made between the strategic participation and tactical expenditure decisions. The paper is based on surveys on R & D in the Dutch industry in 1988 and 1992.
1) Productivity and Its Relationship with Competitive Strategy Formulation, Celik Parkan / City Polytechnic of Hong Kong, AR Dept, 83 Tat Chee Av, Kowloon, Hong Kong We report on the results of interviews with various organizations in the manufacturing and service sectors in Hong Kong and China. The purpose of the interviews was to understand the prevailing perception of the concept of productivity, its relationship with operational competitiveness, and its significance in strategy formulation.
2) Optimization of Buffer Allocation in Automatic Assembly Systems, John W Leung / City Polytechnic of Hong Kong, Dept of Applied Stat & Op Res, Tat Chee Rd, Hong Kong, K K Lai / City Polytechnic of Hong Kong, Tat Chee Av, Dept of Applied Stat & O R, Kowloon, Hong Kong Most researchers have focused on developing approaches to evaluate or predict the performance of assembly systems. This paper focuses on developing models for the optimization of buffer allocation for automatic assembly systems. Guidelines will be presented to help engineers and management in selecting the "best" buffer storage allocation configuration.
3) Scheduling Reservation Operators: The Effects of Assumed Call-Time Distributions, Jerome D Wiest / City University of Hong Kong, 83 Tat Chee Av, Kowloon, Hong Kong A mixed mathematical programming/heuristic/simulation model for scheduling information-reservation operators at a large Asian airline company is described.In the absence of relevant empirical data, various assumptions regarding the distribution of call times are tested, to measure the sensitivity of simulation outcomes to the choice of several mathematical distributions examined. Several of these distributions yield almost identical results, in terms of design parameters for the information/reservation system. Differences in simulation outcomes seem to be related to the standard deviations of the distributions compared.
1) Supporting Shell Environment for Expert System Construction in CIM Systems, Dragan M. Eric / D P N P Sloboda, Ratka Mitrovica B.B., 32000 Cacak, Yugoslavia, Mihailo Mladjenovic / Oshawa, Toronto, Canada This paper shows some possibilities of applications experts systems in CIM systems. KES II (Knowledge Engineering System II) shell systems are used. A fundamental of that system is the development base of knowledge.
2) Object Oriented Mathematical Modeling in Smalltalk, Kiriakos Vlahos / London Business School, Regents Park, London Nw1 4Sa, Uk, Akin Adamson / London Bus Sch, Regents Park, London Nw1 4Sa, Uk OOMP is an object-oriented mathematical programming language and supporting environment which aims to bring the benefits of object orientation and graphical modeling to the widely used mathematical modeling languages such as GAMS and AMPL. The main features of the language are discussed as well as the implementation of the language in the Smalltalk programming environment. The iconic model representation and graphical model design capabilities are also described.
3) Object-Orientation: A Summing Up, Ramkumar Ramaswamy / Infosys Tech Ltd, Plot No 44 & 97A, 3rd Cross, Konnappana Agrahara, Elect City Bangalore, 562 158, India Object-orientation (OO) is the latest buzzword in the information systems field. However, OO is far from being a silver bullet. In this paper we summarize the status of the OO paradigm, with special reference to OO as an Analysis and Design methodology.
4) An Expert System for Underwriting Personal Catastrophe Liability Policies, Talluru Lakshminarayana Rao / Penn State Univ, The Behrend College, Erie, PA 16563-1400, USA Underwriting a personal catastrophe liability (PCL) policy involves a careful evaluation of client's personal, professional, financial, and other demographic factors. The underwriting process is considered complex and requires the expertise of an experienced underwriter. Insurance companies are looking for cost effective ways to carry out the underwriting task. This paper presents an expert system to underwrite the PCL policies. A protype system will be demonstrated to highlight the importance of the research.
1) Individual Behavior & Group Performance in a Computer-Mediated Group Problem Solving Environment, William Rybolt / Babson Coll, Math/Science Division, Babson Park, MA 02157, USA This paper describes a pilot experiment examining individual behavior and group performance in a computer-mediated group problem-solving environment. The results are examined using a set of generic variables that define a model intended to aid in the design and implementation of CSCW systems.
2) IT Impact on Office Productivity, Jaak Jurison / Fordham Univ, Grad Sch of Bus, 113 West 60th St., New York, NY 10023, USA Improving productivity in service industries is a major challenge for managers. This paper describes the results of a longitudinal office productivity study. It analyzes the impact of an integrated office information system on different categories of office workers and develops guidelines for future IT implementations in office settings.
3) IT Investment and Its Impact in Developing Countries, Dennis Kira / Concordia Univ, 1455 de Maisonneuve Blvd West, Montreal, Quebec, Canada H3G 1M8, Jorge Nava / Concordia Univ, Rio Balsas 32, Cp 39560, Acapulco Gro, Mexico This study investigates the impact IT investments have on organization's performance in developing countries. The financial rations will be used as a performance measure. The results from Mexican experience will be reported.
4) Impact of Information Systems Applications on Organizational Benefits, Yash P. Gupta / Univ of Colo - Denver, Col of Bus Admin, P.O. Box 173364, Denver, CO 80217-3364, USA, Arik Ragowsky / Wayne State Univ, Dept of Acctg, Sch of Bus, Detroit, MI 48202, USA, Toni M Somers / Wayne State Univ, School of Business, Finance & Business Econ Dept, Detroit, MI 48202, USA In this paper we examine if information systems applications directly effect organizational benefits, (e.g., cost reduction) and if they are related to organizational characteristics, (e.g., investment in raw material). The indirect effect of IS applications on organizational benefits through organizational characteristics, as a mediating variable, is determined. We develop a path-analytic model based on a sample of 310 manufacturing firms.
1) A Business Process Model for Logistics Operations in Manufacturing Enterprises, Shigeki Umeda / Musashi Univ, 1-26 Toyotam-Kami, Nerima, Tokyo 176, Japan, Muneo Mutsutani / Mitsubishi Elec Co,, Senya Nikawa / Andersen Co,, Hideo Suzuki / Fujitsu Co, This paper represents a novel business process model, which represents information-flows and material-flows in manufacturing enterprises logistics operations. The model includes a hierarchical information system model, management operations models, and business performance indices. These are the reference models to build strategic logistics systems for manufacturing enterprises.
2) DRP: An Information Technology for Logistics Integration, Chrwan-Jyh Ho / Oklahoma State Univ, 342 CBA, Stillwater, OK 74078, USA The information sharing between suppliers/manufacturers and retailers becomes an important competitive weapon in the current retailing revolution. The purpose of this paper is to present an information technology framework, distribution resource planning, for information integration and supply sourcing.
3) Stochastic Vehicle Routing Problem: State of the Art and Future Directions, Kant Rao / Penn State Univ, 509 L Bus Admin Bldg, University Park, PA 16802, USA, Michael A. Haughton / Penn State Univ, 501 H Bus Admin Bldg, University Park, PA 16802, USA The stochastic vehicle routing problem (SVRP) opens at least two sets of operating strategies for addressing the outbound problems. This paper reviews the state-of-the-art in this line of research and presents specific research questions for extending it.
1) Accelerated Burn-In Process, Y V Hui / City Univ of Hong Kong, Dept of Appl Stat & O R, 83 Tat Chee Av, Hong Kong, L Lu / City Polytech of Hong Kong, Dept of Applied Stats & O R, Tat Chee Av, Kowloon, Hong Kong
2) A Heuristic for Scheduling Train Operators of a Mass Transit System, Wing Cheong Ng / City Polytechnic of Hong Kong, Tat Chee Av, Kowloon, Hong Kong This paper studies the problem of scheduling crews of a mass transit system to meet the daily service requirement. Because of the complexity of the problem, it is difficult to solve it optimally. Therefore, the problem is decomposed into several more manageable sub-problems. A heuristic is then developed to solve the problem by constructing a schedule based on the solutions of the sub-problems.
3) Using a Queueing Model to Improve Credit Authorization Operations, W.K. Leung / City Polytech of Hong Kong, Dept of Applied Stats & O R, Tat Chee Av, Kowloon, Hong Kong
4) An AHP Approach for Productivity Measurement, Grang Has / City Polytech of Hong Kong, Dept of Applied Stats & Or, Tat Chee Av, Kowloon, Hong Kong, K K Lai / City Polytechnic of Hong Kong, Tat Chee Av, Dept of Applied Stat & O R, Kowloon, Hong Kong
5) Analysis of Residential Care Service for the Elderly in Hong Kong, Kokin Lam / City Polytech of Hong Kong, AR Dept, 83 Tat Chee Av, Kowloon, Hong Kong The Hong Kong elderly population is continuously increasing and families are increasingly less able to serve as the sole carer of their elderly member. We analyze the difficulties associated with the provision of residential services for the elderly using computer simulation. The simulation program helped decision makers the explore what-if scenarios associated with system capacity, selection criteria, and other factors.
1) A Multiple Criteria Method to the Generation of Alternatives for Weapon Systems, Shinn Sun / Univ of New South Wales, Dept of Comp Sci, Univ College, Adfa, Canberra Act 2600, Australia This paper describes an interactive method for solving a discrete multiple criteria problem under uncertainty. The proposed method concentrates on the selection of weapon systems. The method takes into account alternative generation, aspiration levels, and uncertainty regarding state of nature. An implementation of the method is presented in this paper.
2) Capital Investment with Multiple-Choice Requirement, Edward Y H Lin / Univ of New Brunswick, Faculty of Administration, Fredericton, N.B., E3B 5A3, Canada Several multiple choice programming problems useful to model various types of capital investments under different conditions are identified. These problems can be considered as the variants of multiple-choice knapsack problem. Efficient solution approach towards each type of the problem is presented based on a broad literature review and study.
3) Implementing Multicriteria Resource Allocation Model in Public Organizations, David Ho / Ryerson Polytechnic Univ, School of Admin & Info Mgmt, 350 Victoria St, Toronto Ontario, M5B 2K3, Canada, Dan Chai / Ontario Hydro Tech, 800 Kipling Av, Toronto, Ontario, M8Z 5S4, Canada This paper discusses the implementation of a multicriteria decision model in Ontario Hydro, the electric utility serving the Province of Ontario. The model, which employs ordinal data, is suited for resource allocation in the presence of a large number of alternatives and fuzzy criteria, which are typical of public organizations.
4) The Process of Multiple Criteria Decision Making: A Case Study of Procuring Weapon Systems, Shinn Sun / Univ of New South Wales, Dept of Comp Sci, Univ College, Adfa, Canberra Act 2600, Australia We investigate the process of how a defence community makes weapon procurement decisions to develop a decision-aiding method for the evaluation and selection of weapon systems. In this study, we conduct the field study, the questionnaire surveys, and the interviews to obtain a better understanding of the decision-makers' thought processes when engaged in making the decisions. Many interesting conclusions regarding the information to enhance the design and development of a methodology for the evaluation and selection of weapon systems emerged.
5) A Multiobjective Faculty Course Assignment Model, Adli Mustafa / Univ Sains Malaysia, Sch of Mathematics Sci, 11800 Penang, Malaysia, Mark Goh / Natl Univ of Singapore, Fac of Bus Adm, 10 Kent Ridge, Crescent, Singapore, 0511, Singapore This paper describes a network-based multiobjective faculty course assignment model and the implementation of the model using a readily available user-friendly package called DINAS (Dynamic Interactive Network Analysis System). The conflicting objectives of entertaining the faculty course preferences with the consideration of the faculty course effectiveness as well as the faculty members request for a free from teaching semester are suggested for use. Several aspects on the use of DINAS as a solution tool are discussed.
1) Bayesian Adaptive Maintenance Plans Using Initial Expert Reliability Estimates, Khalid Aboura / C S I R O, Div of Maths & Stats, Private Bag No. 2, Glen Osmond Sth, 5064, Australia Informed judgement consisting of reliability estimates is used to assess prior distributions for the parameters of the Weibull and Generalized Gamma models. The approach is used to initiate adaptive maintenance plans in large scale structures. Examples are the replacement of light bulbs in city streets and large department stores.
2) Detection and Isolaton of Small Malfunctions in Complex Stochastic Systems, Zvi Covaliu / George Washington Univ, Mgmt Sci Dept, Washington, DC 20052, USA We describe a state-space algorithm for isolating small process and measurement malfunctions in complex linear, stochastic systems, and an application to a nuclear power plant model. The algorithm, based on binary residuals, is fast, sensitive, accurate, and has low false-alarm rate for a broad range of malfunctions. A comparison with Bayesian methods is made.
3) Optimal Stopping Rules for Software Testing, Refik Soyer / George Washington Univ, Dept of Mgmt Sci, Monroe Hall 402, Washington, DC 20052, USA We address the problem of when to terminate the testing/modificaton process and to release the software during the development phase. We present a Bayesian decision theoretic approach by formulating the problem as a sequential decision problem. By using a nonGaussian Kalman filter type of model to track software reliability, we are able to obtain tractable expressions for inference and determine a one-stage look ahead stopping rule.
4) A Generalized Block Replacement Policy of a System Subject to Shocks, Shey-Huei Sheu / Natl Taiwan Inst of Technology, Dept of Industrial Mgt, Taipei Taiwan, Rep of China A generalization of the block replacement policy (BRP) is proposed and analysed for a system subject to shocks. Under such a policy an operating system is preventively replaced at times kT (k = 1, 2, 3..) as in the ordinary BRP, and the replacement of the failed system at failure is not mandatory; instead, a minimal repair to the system can be made. The choice of these two possible actions is based on some random mechanism which depends on the number of repairs since the last replacement. The aim of this paper is to derive the expected long-run cost per unit time and find the optimal block interval T| which minimizes the expected long-run cost per unit time of the policy under certain conditions.