Computation Section
Process Flow Optimization
 - Resources and Materials
The second option produces a linear programming model that adds to the product variables, variables that specify the time used on each resource and the amounts of each raw material. It includes constraints on the amounts of raw materials and the amounts of resources available. It determines the optimum product mix with these constraints included.

Clicking OK presents the Linear Model dialog shown below. As for the LP1 model, the number of variables and number of constraints can be increased, but not decreased.

The figure below shows the model constructed with the second model option. The data for the model is derived directly from the data on the Project Worksheet. The model produced can be solved with the built in Excel optimizer (Solver add-in) or the LP Solver Add-in. The solution shown is the optimum product mix for the example. In addition to the sales value, the hours required for the resources and the amounts of the raw materials are explicitly displayed in the variable value row of the LP solution. The model allows simple upper bounds for the raw material amounts and resource times.
The optimum sales quantities are transferred to the Sales column on the Project worksheet. The numbers in the column are linked by formula to the Project LP2 worksheet, and the column is colored yellow. When features of the LP model are changed and the model solved, the solution is reflected in the sales column. The user can change numbers in the sales column, but the automatic links to the Project LP2 worksheet are lost.


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tree roots

Operations Management / Industrial Engineering
by Paul A. Jensen
Copyright 2004 - All rights reserved

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