EM 505 – DECISION MODELS Spring 2021, METU Case Study 1 Due date: May 21, 2021 Fortune Electronics has just signed a contract to supply searchlights to the U.S army. During the next four months, the firm must meet the following delivery schedule: February 150 units March 160 units April 225 units May 180 units Fortune’s factory in Texas can produce searchlights at a cost of $20 per unit (labor cost is not included). To produce a searchlight 10 hours of labor are required and there are 10 workers available at the plant at the beginning of February. Each worker can work 160 hours per month in regular hours with a rate of $1.5 per hour, and 80 hours in overtime per month with a rate of $2.5. It is possible to hire new workers or to layoff some of the existing workers at the beginning of a month. A one-time additional cost for hiring and layoff of a worker is $400 and $1000, respectively. Assume that it is possible to have non-integer number of workers. It is also possible to subcontract some of the searchlights to another factory at a cost of $50 each, but the subcontractor has a production capacity of 10 units. Searchlights can be carried in inventory to meet the demand of a future month, but this costs $5 per unit per month, but the storage has a capacity of 20 units. Backordering is also allowed with a cost of $7.5 per unit per month. Formulate a linear programming model to represent Fortune’s problem and find the optimal decisions. Use Excel Solver to find the solution. Answer the following questions and interpret the results. a. How much should the subcontractor lower its price to become competitive in period 4? b. How much lower does the inventory carrying cost need to be in order inventory be carried in period 3? c. How much should the hiring cost go down in each period so that workers would be hired? d. At what layoff cost would the company consider laying off workers? e. If Fortune’s could negotiate to lower the demand in some period, which period would they do so? f. How much lower does the backordering cost need to be in order backordering be favorable in each period?