Management of Suncoast Office Supplies establishes monthly goals, or quotas, for the types of customers contacted. For the next 4 weeks, Suncoast's customer contact strategy calls for the sales force, which consists of four salespeople, to make 200 contacts with customers who have previously purchased supplies from the firm. In addition, the strategy calls for 120 contacts of new customers.

Making allowances for travel and waiting time, as well as for demonstration and direct sales time, Suncoast has allocated 2 hours of sales force effort to each contact of a previous customer. New customer contacts tend to take longer and require 3 hours per contact. Normally, each salesperson works 40 hours per week, or 160 hours over the 4- week planning horizon; under a normal work schedule.

Management is willing to use some overtime, if needed, but is also willing to accept a solution that uses less than the scheduled 640 hours available. However, management wants overtime of at most 40 hours and underutilization of the work force limited to at most 30 hours over the 4-week period.

In addition to the customer contact goals, Suncoast has established a goal regarding sales volume. Based on experience, Suncoast estimates that each previous customer contacted will generate $250 of sales and each new customer contacted will generate $125 of sales. Management would like to generate sales of at least $70,000 for the next month.

Assume that each of five goals; number of previous customers to call, number of new customers to call, man-hour overtime, man-hour underutilization, and sales revenue to reach, are equally important for the company. So, use goal programming to model the customer call problem of the company such that you try to minimize the total weighted undesired deviations from the targets. Provide your formulation and solve it in excel.

Solve it by goal programming.