Hungarian Method
- 2. INTRODUCTION
An assignment problem is a special type of linear
programming problem where the objective is to minimize
the cost or time of completing a number of jobs by a
number of persons.
One of the important characteristics of assignment problem
is that only one job (or worker) is assigned to one machine
(or project).
This method was developed by D. Konig, a Hungarian
mathematician and is therefore known as the Hungarian
method of assignment problem.
- 4. SOLUTION OF ASSIGNMENT
PROBLEM
Step 1. Determine the cost table for the given problem.
(i) If the no. of sources is equal to no. of destinations, go to step
3.
(ii) If the no. of sources is not equal to the no. of destination, go
to step2.
Step 2. Add a dummy source or dummy destination, so
that the cost table becomes a square matrix. The cost
entries of the dummy source/destinations are always
zero
- 5. Step 3. Locate the smallest element in each row of
the given cost matrix and then subtract the same
from each element of the row.
Step 4. In the reduced matrix obtained in the step 3,
locate the smallest element of each column and then
subtract the same from each element of that column.
Each column and row now have at least one zero.
53 96 37
47 87 41
60 92 36
a
16 59 0
6 46 0
24 56 0
a
10 13 0
0 0 0
18 10 0
- 6. Step 5. In the modified matrix obtained in the step 4,
search for the optimal assignment as follows:
(a) Examine the rows successively until a row with a single zero is
found. Enrectangle this zero and cross off all other zeros in its
column. Continue in this manner until all the rows have been
taken care of.
(b) Repeat the procedure for each column of the reduced matrix.
(c) If a row and/or column has two or more zeros and one cannot
be chosen by inspection then assign arbitrary any one of these
zeros and cross off all other zeros of that row / column.
(d) Repeat (a) through (c) above successively until the chain of
assigning or cross ends.
- 7. 10 13 0
0 0 0
18 10 0
- 9. 10 13 0
0 0 0
18 10 0
- 10. Step 6. If the number of assignment is equal to n (the order of
the cost matrix), an optimum solution is reached.
If the number of assignment is less than n(the order of the matrix),
go to the next step.
Step7. Draw the minimum number of horizontal and/or
vertical lines to cover all the zeros of the reduced matrix.
Step 8. Develop the new revised cost matrix as follows:
(a)Find the smallest element of the reduced matrix not covered by
any of the lines.
(b)Subtract this element from all uncovered elements and add the
same to all the elements laying at the intersection of any two lines.
Step 9. Go to step 6 and repeat the procedure until an
optimum solution is attained.
- 11. 0 3 0
0 0 10
8 0 0
- 12. 0 3 0
0 0 10
8 0 0
0 3 0
0 0 10
8 0 0
SOLUTION
- 13. Example 1: You work as a sales manager for a toy manufacturer, and you
currently have three salespeople on the road meeting buyers. Your
salespeople are in Austin, TX; Boston, MA; and Chicago, IL. You want
them to fly to three other cities: Denver, CO; Edmonton, Alberta; and
Fargo, ND. The table below shows the cost of airplane tickets in dollars
between these cities.
From To Denver Edmonton Fargo
Austin 250 400 350
Boston 400 600 350
Chicago 200 400 250
Where should you send each of your salespeople in order to
minimize airfare?
- 16. APPLICATIONS
In assigning machines to factory orders.
In assigning sales/marketing people to sales territories.
In assigning contracts to bidders by systematic bid-
evaluation.
In assigning teachers to classes.
In assigning accountants to accounts of the clients.