A large Saskatchewan feed mill, B. Swart Processing, prepares its six-month aggregate plan by forecasting demand for 50 pound bags of cattle feed as follows: January, 1000 bags; February 1000 bags; March 1300 bags; April 1500 bags; May 1500 bags; June 1400 bags.

The feed mill plans to begin the new year with no inventory left over from the previous year, and backorders are not permitted. It projects that capacity (during regular hours) for producing bags of feed will remain constant at 800 until the end of April, and then increase 1100 bags per month when a planned expansion is completed on May 1. Overtime capacity is set at 300 bags per month until the expansion, at which time it will increase to 400 bags per month. A friendly competitor in Alberta is also available as a backup source to meet demand - but can provide only 500 bags total during the six-month period.

Develop a six month production plan for the feed mill using the transportation method.

Cost data are as follows: Regular-time cost per bag (until April 30) $12.00 Regular-time cost per bag (after May 1) $11.00 Overtime cost per bag (during entire $16.00 period) Cost of outside purchase per bag $18.50 Carrying cost per bag per month $ 1.00