The required maintenance workload for the next four months in a food processing plant is $550,$

$400,360,$ and $445$ man$-$hours, respectively. The demand can be met by either regular time at a cost

of SR $40$ per hour, overtime at a cost of SR $70$ per hour or subcontract at cost of SR $95$ per hour.

Regular time capacities are listed following, overtime capacity cannot exceed $25\%$ of regular time

capacity at any month. Late maintenance $($backlog$)$ costs extra SR $15$ per hour per Period.

Subcontract hours are available but can only be purchased in $120-$hour contract. $($This means that

you cannot use less than $100$ hours of subcontract hours, increment of $100$ hours$).$

Using the heuristic tableau method, develop the capacity plan to satisfy the required

workload

Calculate the total cost of the plan

If the subcontract hour can be used without any constraints $($any limit on the number of

hours$).$ How much that would save on the total cost of the plan?