Hi,
I am using the Excel Solver to optimize my production-quantity. Now I have a
problem with 2 products X & Y which are produced on the same machine:
The sum of production of X & Y is capacity constrained. There are also
restrictions concerning a minimum and maximum inventory for both products.
Demand should be satisfied each month. Demand can be satisfied through usage
of inventory, production and external purchase of a product.
The Solver should minimize costs (inventory=cheapest, purchase=most
expensive) times quantities of inventory, production and purchase.

The problem is the following:
The production of product Y is a campaign. That means the production should
only start when there are insufficient inventories of Y. If it starts the
minimum production quantity is 500. If the inventory is sufficient, the
production should be 0.

As you can see in the example file that doesnt work at the moment. The
Solver cant find a solution and the production of Y is min. 500 each month.
Do you have any ideas how to solve it correctly? Is it possible to use an
If-Then-Else Equation with the Solver?
http://www.herber.de/bbs/user/66575.xls