Develop another plan for the Mexican roofing manufacturer described in Examples 1 to 4 ( pages 526– 530) and Solved Problem 13.1 ( pages 540– 541).

a) For this plan, plan 5, the firm wants to maintain a constant workforce of six, using subcontracting to meet remaining demand. Is this plan preferable?

b) The same roofing manufacturer in Examples 1 to 4 and Solved Problem 13.1 has yet a sixth plan. A constant workforce of seven is selected, with the remainder of demand filled by subcontracting.

c) Is this better than plans 1– 5?