Periodic preventive maintenance is carried out on aircraft engines,...

Periodic preventive maintenance is carried out on aircraft engines, where an important component must be replaced. The number of aircraft scheduled for such maintenance over the next 6 months is estimated at 200,180, 300,198,230, and 290, respectively. All maintenance work is done in the month that parts are available, where a used component may be replaced with a new or an overhauled component. The overhauling of used components may be done in a local repair facility, where they will be ready for use at the beginning of next month, or they may be sent to a central repair shop where a delay of 2 months (as such maintenance can occur in the third month) is expected. The repair cost in the local shop is $120 per component. At the central facility, the cost is only $35 per component. An overhauled component used in a later month will incur an additional storage cost of $1.50 per unit per month. New components may be purchased at $200 each in month 1, with a 5% price increase every 2 months. A new component is available immediately (no delay).

Formulate a model to the problem and solve to determine the optimal schedule for satisfying the demand for the component over the next 6 months. Also consider that the planning occurs within the first month. So all parts are ordered in the first month to satisfy maintenance requirements