900 Manufacturer of roofing supplies has developed monthly forecasts for a family of products. Data for 6 month period (January to June) are presented in table below. Month Expected demand Production days Demand per day January 22 February 700 18 March 800 21 April 1200 21 May 1500 22 June 1100 20 Total 6200 124 Cost information: Inventory carrying cost $5 per unit per month Subcontracting cost per unit Average pay rate $20 per unit $10 per hour ($80 per day) $17 per hour (8h per day) $1.6 hours per unit Overtime pay rate Labor hours to produce a unit Cost of increasing daily production rate (hiring&training) Cost of the decreasing daily production rate (lay off) $300 per unit $600 per unit The firm would like to begin development of an aggregate plan. You are requested to do it