Hello guys!I'm new in this forum and I just want to ask if there is any answer to this problem posted on
October 2010 because I'm facing exactly the same problem.Thanks a lot

"This is a multiperiod production problem scheduling problem. Plastic Molding manufacturer is planning the production storage and marketing of a product whose demand and selling price vary seasonally.The company is in the process of developing a manufacturing strategy. According to the formulated strategy, the company wants to manufcature the product in the seasons during which production costs are low, and then store and sell product when selling price is high. The manufacturer has obtained the following estimates of the demand, cost, capacity, and expected selling price of the product for each period.

Let Pj = Product made (in tons) during period j.
Ij= product left in storage at the end of period j
Dj= product demanded during period j
Beginning inventory = 500 tons
Desired ending inventory = 500 tons
(inventory ) storage cost = $2 per ton form one period to the next


Period ----Production cost ----Production capacity---- Demand---- Price
1 ---------20------------------ 1500---------------------1100 -------180
2 ---------25------------------ 2000--------------------- 1500 -------180
3 ---------30 ------------------2200 --------------------1800 --------250
4 --------40------------------- 3000 --------------------1600 --------270
5 -------50 --------------------2700 --------------------2300 --------300
6 -------60 --------------------2500-------------------- 2500 --------320 "