… number of units of product A to be produced

… number of units of product B to be produced

… number of units of product C to be produced

… number of units of product D to be produced

P … total profit

**2. Objective
function**

*Maximise: *

The first set of constrains is related to the limited sources. There are requirements of the production in the left-hand side and maximal disposable capacity (or financial funds) in the right-hand side.

Following constrains reflect the fact that the production can have upper or lower limits usually given by contracts with customers.