4.3 Multi-Period Workforce Scheduling (Manpower Planning): CSL's workforce-scheduling problem. (83.12, p.109) CSL is a chain of computer service stores. The numbers of hours of skilled repair time that CSL requires during the next five months are as follows: 1. January 2. February 3. March 4. April 5. May 6,000 hrs 7,000 hrs 8,000 hrs 9,500 hrs 11,000 hrs At the beginning of January, 50 skilled technicians work for CSL. Each skilled technician can work up to 160 hours per month. To meet future demands, new technicians must be trained. It takes one month to train a new technician. During the month of training, a trainee must be supervised for 50 hours by an experienced technician. Each experienced technician is paid $2,000 a month (even if he or she does not work the full 160 hours). During the month of training, a trainee is paid $1,000 a month. At the end of each month, 5% of CSL's experienced technicians quit to join Plum Computers. Formulate an LP whose solution will enable CSL to minimize the labor cost incurred in meeting the service requirements for the next five months. 1. Decision Variables. 2. Linear Program