
216 Numerical Methods and Optimization: An Introduction
In addition, it is required that at least half of the day-shift nurses have week-
ends (Saturday and Sunday) off. Formulate this problem as an LP.
Note that a nurse’s schedule can be defined by the first day of the three-day
working cycle. Thus, we can define the decision variables as follows:
x
1
= the number of nurses working Mo-Tu-We schedule
x
2
= the number of nurses working Tu-We-Th schedule
x
3
= the number of nurses working We-Th-Fr schedule
x
4
= the number of nurses working Th-Fr-Sa schedule
x
5
= the number of nurses working Fr-Sa-Su schedule
x
6
= the number of nurses working Sa-Su-Mo schedule
x
7
= the ...