Laura: The production planning problem we're looking at here is determining the launch of production in a given period with the number of units (or of parts) to be produced. Suppose we have 6 weeks whose requests clientele are 100, 200, 250, 225, 300 and 125 units for weeks 1 to 6, respectively. The capacity of the weekly production is assumed to be infinite. The production can be started on Monday morning and it must be stopped on Friday evening of every week. The production launch each week costs $ 1000 * and each unit manufactured costs $ 20, $ 25, $ 15, $ 10, $ 20 and $ 30, respectively for weeks 1 to 6 **. It is possible to produce more than demand weekly and store the surplus from one week to the next with a storage cost $ 2 per piece. Give a mathematical optimization model that makes it possible to find a plan of production in order to minimize the costs mentioned above. * If the production is not launched within a week; then the cost of launching the production is zero. ** Example: if we decide to produce 100 units in week 1, it costs us: 1000$+20 $*100