Can someone help me figure out the deciding variables and constraints for this problem?
A company has signed contracts to deliver 30 units of their product in June, 15 units in July and 15 units in August. They begin June with 5 units in the inventory. They can produce 15 units per month on regular time shifts at a unit cost of P100 and 5 additional units per month on an optional overtime shift at a unit cost of P120. They can store units at P8 per unit per month. They can also have the option to borrow units from a similar producer at a cost of P10 per unit per month until they can repay him in units from their own production. This allows them to deliver units ahead of the time they produce them.
Thanks!