Problem:
Snookers Restaurant is open from 8am to 10pm daily. Besides the hours that they are open for business, workers are needed tan hour before opening and an hour after closing for setup and cleanup activities. The restaurant operates with both full-time and part-time workers on the following shifts:
Shift Dailty Rate
7am-11am $32
7am-3pm $80
11am-3pm $32
11am-7pm $80
3pm-7pm $32
3pm-11pm $80
7pm-11pm $32
The following numbers of workers are needed during each of the indicated time blocks.
Hours Workers Needed
7am-11am 11
11am-1pm 24
1pm-3pm 16
3pm-5pm 10
5pm-7pm 22
7pm-9pm 17
9pm-11pm 6
At least one full-time worker must be available during the hour before opening and after closing. Additionaly, at least 30% of the employees should be full-time 8 hour workers during the restaurant's busy periods from 11am to 1pm and 5pm to 7pm.
a) Formulate an ILP for this problem with the objective of minimazing total daily labor costs.
b) Implement your model in a spreadsheet and solve it
c) What is the optimal solution?