integer programming excel solver examples

Instead of setting a specific target value for a variable, the goal is to find the optimum value for one or more target variables, under certain constraints. To solve the problem click theīutton.Solver is a Microsoft Excel add-in program you can use for optimization in what-if analysis.Īccording to O'Brien and Marakas, optimization analysis is a more complex extension of goal-seeking analysis. At this point you have defined the model for the solver.Ĭhoose in the Select Solving Method 'Simplex LP' and check 'Make Unconstrained Notice that if all the constraints were the same type we could have been able to enter all the constraints at once. This would have taken care first two constraints. In the add constraint dialog box in the 'cell reference box' enter D7.D8, choose <=, and enter for constraint E7.E8. For instance you could have entered the first two constraint together in one operation. Speed tip: You can enter more than one constraint at a time as long as they all have the same direction. Do this for all constraintsīy clicking add tab repeatedly. (here <=) move the insertion point to the right box and enter the adress of Enter (or point to) the cell containing the LHS of the first constraint (has to be a formula, here D7) in the box on the left , choose the appropriate logical operator (=, or =) Push the Add button to get the Add constraint dialog box. Move the insertion cursor to By Changing Variable Cells box and enter or point to the range of variables (here B3.C3). Select the Min or Max radio button (Max here). To ' Set Objective '' box, point to the address of the objective function (this has to be a formula, here D5). This will bring the Solver Parameters dialog box. Select Data on the ribbon, then Solver from the menu. Constraint Formulas -Excel formulas representing the left hand sides (LHS) of the constraints.The range of cells containing the problem variables (Excel's term is changing variable cells).Whether you are maximizing or minimizing (here Max).Objective function cell (In the example this is.You must define the problem for the solver by identifying several things: Finally column labeled RHS contains the Right hand sides or the constants of the constraints. In fact, if you write the formula in D7 as SUMPRODUCT(B2.C2,$B$3.$C$3) you can simply copy it to cells D8 through D11. Column labeled LHS contains formulas to calculate the left-hand sides of the respective constraints, e.g., D7 has the formula =B3*B7+ C3*C7 (or the SUMPRODUCT form) etc. The objective function is represented as a formula =ī2*B3 + C2*C3 in D5 (or a better way is SUMPRODUCT(B2.C2,$B$3.$C$3) which is entered to cell D5. Row 2 contains the objectiveįunction coefficients, row 3 quantities (solution), and finally rows 7-11 Rows B and C are used for the two variables. Here column A is used for descriptive labels for various For instance, to solveĬonsider the following worksheet for the same problem

i.e., rows representing constraints and columns representing variables. Although many formats are possible, one widely used format arranges the spreadsheet representation of the problem as they are generally written. The only requirements are that you have cells for the problem variables a formula representing the objective function and formulas representing the left hand sides of the constraints. The problem can be represented in a wide variety of ways. To do this you (1) create a worksheet representation of the model (2) define the problem to the solver add-in (3) solve the problem (4) view and/or print the results and (5) save the problem and/or the results.ġ. This note describes the use of SOLVER to solve a linear programming problem. Excel has a tool called SOLVER that solves various mathematical programming problems.

Most spreadsheet programs have the capability to solve small linear programming problems. Solving Linear Programming Problems Using EXCEL

Integer programming excel solver examples