A factory can only produce one batch a time. The more capacity a factory has, the faster it produces a batch of a given size. The cost of a factory building is $500,000 regardless of the factory capacity. The cost of factory equipment and fixtures is proportional to capacity: Capacity of one drum per day costs $50,000. For example, the cost to build a new factory with a capacity of 5 drums per day is $500,000 + (5)$50,000 = $750,000. Adding an additional capacity of 2 drums per day later would cost (2)50,000 = $100,000.

It takes 90 days to either construct a new factory or to add capacity to an existing factory. The cost of the factory is incurred as soon as construction begins. Capacity cannot be retired.

Production in factories is carried out in batches, where each batch is an integer number of drums set by you. The cost to produce one batch equals $1500 plus the number of drums in the batch times $1000. For example, the cost to produce a batch of 10 drums is $1500 + (10)$1000 = $11,500.