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Unformatted text preview: : Operations Modeling, Fall 2009 Space Formulation of a mathematical model for the pet food distributor’s problem Decision variables: represent decisions by variables. Objective function: express the performance criterion in terms of the decision variables; should it be minimized of maximized? IOE 202: Operations Modeling, Fall 2009 Page 18 Space Formulation of a model for the pet food distributor’s – cont. Constraints: express all (explicit and implicit) constraints and restrictions on the values of the decision variables. IOE 202: Operations Modeling, Fall 2009 Page 19 Space Mathematical model for pet food distributor’s problem Decision variables: x1 , x2 , x3 , x4 : lbs of food ordered in each of the 4 months s1 , s2 , s3 , s4 : lbs of food stored/sold at the end of each of the 4 months y1 , y2 , y3 , y4 : lbs of food donated in each of the 4 months Mathematical model: minimize 5x1 + 8x2 + 4x3 + 7x4 +2(s1 + s2 + s3 ) − 6s4 (Net) cost objective subject to x1 = 50 + s1 + y1 Inventory balance in month 1 constraint x2 + s1 = 65 + s2 + y2 Inventory balance in month 2 constraint x3 + s2 = 100 + s3 + y3 Inventory balance in month 3 constraint x4 + s3 = 70 + s4 + y4 Inventory balance in month 4 constraint x1 , x2 , x3 , x4 ≤ 80 Ordering capacity constraint(s) x1 , x2 , x 3 , x4 , Nonnegativity constraint(s) s1 , s2 , s3 , s4 , y1 , y2 , y 3 , y4 ≥ 0
IOE 202: Operations Modeling, Fall 2009 Page 20...
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This note was uploaded on 03/17/2010 for the course IOE 202 taught by Professor Marinaepelman during the Fall '09 term at University of Michigan-Dearborn.
- Fall '09