INTRODUCTION TO MANAGEMENT SCIENCE Today’s Topic: 1. Define Management Science 2. Modeling and Models 3. Problem Solving and Decision Making Process 4. Quantitative Models 5. Management Science In Practice 6. History of Linear Programming 1. Define Management Science (Operations Research) a scientific (quantitative) approach to decision making that involves operations the art of giving bad answers to problems which otherwise worse answers are given quantitative common sense an aid for executives to make decisions ways to effectively use information 2. Modeling and Models Physical models Graphic models Quantitative models * deterministic * probabilistic * descriptive * prescriptive -- Advantages of using models cost time risk what-if question 3. Problem Solving and Decision Making Process define the problem choose the criteria (single or multiple) formulate model collect data verify model choose an alternative (quantitatively or qualitatively) implement the selection evaluate the result 4. Quantitative Models -- When to use? problem is complex problem is important and needs a thorough analysis problem is new problem is repetitive and time consuming what if questions -- Components of quantitative models controllable inputs (decision variables) uncontrollable inputs (parameters): deterministic or stochastic objective function constraints outputs -- An Example: The Erlanger Manufacturing Company makes two products. The contribution to profit is $25 for each unit of product 1 and $30 for each unit of product 2. The labor-hour requirements for the products in each of two production departments are summarized below: Product 1 2 Department A 1.5 3.0 Department B 2.0 1.0 For the current production period, Erlanger has the following number of labor-hours available in each department: 450 hours in Department A and 350 hours in Department B. Assume that Erlanger’s objective is to maximize the total contribution to profit. 5. Management Science In Practice -- Optimization techniques linear programming integer programming network models project management goal programming -- Other statistical techniques simulation forecasting queuing models inventory models -- Methods used most frequently in corporate world regression, forecasting simulation project management linear programming queuing -- Techniques most familiar to practitioners linear programming simulation network models queuing -- Sample applications of optimization techniques Organization Nature of Applications Monsanto Optimize production operations in chemical plants to Corp. meet production targets with minimum cost. Weyerharuser Optimize how trees are cut into wood products to Co. maximize their yield. Eletrobras/C Optimally allocate hydro and thermal resources in the EPAL, Brazil national electrical generating system. United Schedule shift work at reservation offices and airports Airlines to meet customer needs with minimum cost. San Francisco Optimally schedule and deploy police patrol officers Police with a computerized system. Department Texaco, Inc. Optimally blend available ingredients into gasoline products to meet quality and sales requirements. Yellow Optimize the design of a national trucking network Freight and the routing of shipments System, Inc. American Design a system of fare structures, overbooking, and Airlines coordinating flights to increasing revenues. New Haven Design an effective needle exchange program to Health Dept. combat the spread of HIV/AIDS. 6. History of Linear Programming started in WWII simplex method by Dantzig computer revolution business applications ellipsoid algorithm interior point method Annual Savings $2 mil $15 mil $43 mil $6 mil $11 mil $30 mil $17.3 mil $500 mil 33% less HIV