Chapter 4 Linear Programming Models

Introduction All of the models in this chapter are linear models Which means: Target cell is ultimately (possibly through a series of formulas in intervening cells) a sum of products of constants and changing cells a “constant” does not depend on changing cells

Introduction each side of each constraint is either a constant or a sum of products of constants and changing cells each changing cell (except in a few cases where it’s specified otherwise) is allowed to contain a continuous range of values, not just integer values.

Key points to remember Determine the changing cells: – contain the values of the decision variables. – should contain the values the decision maker has direct control over, – should determine all other outputs, either directly or indirectly.

Key points to remember Set up the spreadsheet so that you can easily compute what you want to maximize or minimize (usually maximize profit or minimize cost) Set up the spreadsheet so that the relationships between the cells in the spreadsheet and the problem constraints are readily apparent.

Key points to remember Make your spreadsheet readable. – Use descriptive labels, – use range names liberally, – use cell comments and text boxes for explanations, and – think about your model layout before you dive in. – other people are likely to be examining your spreadsheet models.