Linear programming model

The following is a linear programming model for the production planning problem. The decision variables for this problem are as follows: xij : total number of product j produced during week i, Iij : total amount of product j in inventory at the end of week i, Where, hij : unit holding cost of product j during week i, dij : demand for product j during week i, cij : unit production cost of product j during week i, j : capacity usage coefficient for product j,  : production (assembling) capacity,  : testing equipment capacity. Minimize the total costs and production and inventory holding costs.