Page 107 -
P. 107

INTRODUCTION TO SENSITIVITY ANALYSIS  87



                        MANAGEMENT SCIENCE IN ACTION



                        Assigning Products to Worldwide Facilities at Eastman Kodak
                            ne of the major planning issues at Eastman  is always changing. Thus, the linear programming
                        O Kodak involves the determination of what prod-  model must be used in a dynamic way. For instance,
                        ucts should be manufactured at Kodak’s facilities  when demand expectations change, the model can
                        located throughout the world. The assignment of  be used to determine the effect the change will have
                        products to facilities is called the ‘world load’. In  on the world load. Suppose that the currency of
                        determining the world load, Kodak faces a number  country A rises compared to the currency of country
                        of interesting trade-offs. For instance, not all manu-  B. How should the world load be modified? In addi-
                        facturing facilities are equally efficient for all prod-  tion to using the linear programming model in a
                        ucts, and the margins by which some facilities are  ‘how-to-react’ mode, the model is useful in a more
                        better varies from product to product. In addition to  active mode by considering questions such as the
                        manufacturing costs, the transportation costs and  following: Is it worthwhile for facility F to spend d
                        the effects of customs duty and duty drawbacks  dollars to lower the unit manufacturing cost of prod-
                        can significantly affect the allocation decision.  uct P from x to y? The linear programming model
                          To assist in determining the world load, Kodak  helps Kodak evaluate the overall effect of possible
                        developed a linear programming model that accounts  changes at any facility.
                        for the physical nature of the distribution problem and  In the final analysis, managers recognize that
                        the various costs (manufacturing, transportation and  they cannot use the model by simply turning it on,
                        duties) involved. The model’s objective is to minimize  reading the results and executing the solution. The
                        the total cost subject to constraints such as satisfying  model’s recommendation combined with manage-
                        demand and capacity constraints for each facility.  rial judgement provide the final decision.
                          The linear programming model is a static repre-
                        sentation of the problem situation, and the real world  Based on information provided by Greg Sampson of Eastman Kodak.




                                      The optimal solution, S ¼ 540 standard bags and D ¼ 252 deluxe bags, was based on
                                      profit contribution figures of $10 per standard bag and $9 per deluxe bag. We are
                                      now told by the Sales Dept. that, because of increased competition they have
                                      reduced prices and the profit contribution for the standard bag has fallen from
                                      $10 to $8.50. Sensitivity analysis can be used to determine whether the production
                                      schedule calling for 540 standard bags and 252 deluxe bags is still best. If it is, solving
                                      a modified linear programming problem with 8.50S +9D as the new objective
                                      function will not be necessary.
                                         Sensitivity analysis can also be used to determine which coefficients in a linear
                                      programming model are crucial. For example, the Accounting Department has
                                      indicated that the $9 profit contribution for the deluxe bag is only a best estimate
                                      and could be lower. The problem for management is that 252 deluxe bags are
                                      currently being produced, based on the $9 profit contribution estimate. If the profit
                                      contribution is actually lower should they stop producing the deluxe bag and switch
                                      production to the standard bag instead? Sensitivity analysis can be used to calculate
                                      how much lower the $9 profit contribution would need to be for the deluxe bag not
                                      to be profitable enough to produce.
                                         Another aspect of sensitivity analysis concerns changes in the right-hand side values
                                      of the constraints. Recall that in the GulfGolf problem the optimal solution used all
                                      available time in the cutting and dyeing department and the finishing department.
                                      What would happen to the optimal solution and total profit contribution if the
                                      company could obtain additional quantities of either of these resources? Sensitivity




                Copyright 2014 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has
                      deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.
   102   103   104   105   106   107   108   109   110   111   112