Globots can be produced by regular-time labor or by overtime labor. Production capacity (number of globots) and production costs during the next 4 quarters are shown in the file P09_11.xlsx. Wivco has set the following goals in order of importance:

■ Goal 1: Each quarter’s demand should be met on time.

■ Goal 2: Inventory at the end of each quarter should not exceed 3 units.

■ Goal 3: Total production cost should be no greater than $250.

Use a goal programming model to determine Wivco’s production schedule for the next 4 quarters. Assume that at the beginning of the first quarter, 1 globot is in inventory.