3. The Assignment Problem
Given a set S of m people, a set D of m tasks, and for each i E S, jED a cost cu associated with assigning person i to task j, the assignment problem is to assign each person to one and only one task in such a manner that each task gets covered by someone and the total cost of the assignments is minimized. If we let: 1
if person i is assigned task j 0 otherwise, then the objective function can be written as: minimize
JED The constraint that each person is assigned exactly one task can be expressed simply as: Exi, .1, for all iES. JED ; Also constraint that every task gets covered by someone is just: 1 , for all jED. iEs - Except for the assumed integrality of the decision variables, xu, the assignment problem is just a Hitchcock transportation problem in which the supply at every supply node (person) is one and the demand at every demand node (task) is also one.