A company wants to assign 14 employees to 10 offices. Each employee has a preference for a certain office. | |||||||||||||||
How should the company assign employees to the offices to maximize the preference of all employees? | |||||||||||||||
Preferences (1=first, 10=last choice) | |||||||||||||||
Office 1 |
Office 2 |
Office 3 |
Office 4 |
Office 5 |
Office 6 |
Office 7 |
Office 8 |
Office 9 |
Office 10 |
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Employee 1 | 3 | 2 | 1 | 4 | 6 | 5 | 8 | 9 | 10 | 7 | |||||
Employee 2 | 5 | 3 | 2 | 6 | 1 | 7 | 9 | 8 | 4 | 10 | |||||
Employee 3 | 10 | 8 | 1 | 9 | 7 | 4 | 3 | 6 | 2 | 5 | |||||
Employee 4 | 7 | 3 | 2 | 9 | 5 | 4 | 8 | 6 | 1 | 10 | |||||
Employee 5 | 1 | 3 | 6 | 8 | 5 | 2 | 9 | 10 | 7 | 4 | |||||
Employee 6 | 4 | 9 | 1 | 5 | 6 | 8 | 2 | 7 | 10 | 3 | |||||
Employee 7 | 2 | 1 | 10 | 9 | 5 | 3 | 6 | 8 | 4 | 7 | |||||
Employee 8 | 6 | 5 | 1 | 3 | 2 | 4 | 7 | 8 | 9 | 10 | |||||
Employee 9 | 8 | 9 | 10 | 5 | 4 | 3 | 2 | 1 | 6 | 7 | |||||
Employee 10 | 9 | 10 | 3 | 2 | 5 | 4 | 1 | 7 | 8 | 6 | |||||
Employee 11 | 7 | 3 | 5 | 2 | 9 | 8 | 1 | 10 | 4 | 6 | |||||
Employee 12 | 6 | 5 | 1 | 9 | 10 | 2 | 3 | 4 | 7 | 8 | |||||
Employee 13 | 6 | 8 | 10 | 9 | 1 | 2 | 3 | 4 | 5 | 7 | |||||
Employee 14 | 6 | 3 | 5 | 9 | 1 | 2 | 10 | 4 | 8 | 7 | |||||
Assignments | Office 1 |
Office 2 |
Office 3 |
Office 4 |
Office 5 |
Office 6 |
Office 7 |
Office 8 |
Office 9 |
Office 10 |
Total | Preference | |||
Employee 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
Employee 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
Employee 3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
Employee 4 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
Employee 5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
Employee 6 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
Employee 7 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
Employee 8 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
Employee 9 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
Employee 10 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
Employee 11 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
Employee 12 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
Employee 13 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
Employee 14 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
Total | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | ||||
Required | 1 | 1 | 1 | 1 | 2 | 1 | 2 | 2 | 2 | 1 | |||||
Problem | |||||||||||||||
A company wants to assign 14 employees to 10 offices. There are four offices that require 2 people. Each | |||||||||||||||
employee has given their preference. A 1 means first choice, 2 means second choice, etc. How should the | |||||||||||||||
company assign the people to the offices to optimize the preferences of the employees? | |||||||||||||||
Solution | |||||||||||||||
1) The variables are the assignments of the people to different offices. On worksheet Offices these are | |||||||||||||||
given the name Assignments. | |||||||||||||||
2) There are the following logical constraints | |||||||||||||||
Assignments = binary | |||||||||||||||
and the other constraints | |||||||||||||||
Assignments_per_employee = 1 | |||||||||||||||
Total_employees = Required_employees | |||||||||||||||
3) The objective is to optimize the preference of the employees. That means we have to minimize the sum | |||||||||||||||
of the total preferences given to the assigned offices, defined on the worksheet as Total_preference. | |||||||||||||||
Remarks | |||||||||||||||
When everybody wants a different office, there will be no problems. If all employees prefer the same | |||||||||||||||
office (more likely!), the problem gets more difficult and it might be necessary to give an employee 7th or | |||||||||||||||
8th choice. It might be wise, in that case, to add a constraint to say that no assignment worse than 5th | |||||||||||||||
choice is given, for instance. This may cause the problem to be infeasible, i.e., there is no possible | |||||||||||||||
solution. If this happens, you will have to relax the constraint on the assignments, e.g. no worse than 6th | |||||||||||||||
or even 7th choice. | |||||||||||||||