In: Operations Management
Part 4. Bank Assignments. A bank distributes checks to different sites to be processed within a large metro area. Each site has the capacity to process different amounts of checks per day. The checks that need to be processed each day are personal, payroll, draft, and government. The total demand is different for each type of check. The cost to process each type of check varies with the site. These values are summarized in the table.
Cost per check |
Site1 |
Site2 |
Site3 |
Site4 |
Site5 |
Total Demand Checks/day |
Personal |
2.55 |
2.35 |
3.22 |
2.85 |
2.25 |
700 |
Payroll |
1.45 |
1.35 |
2.1 |
1.95 |
1.84 |
400 |
Draft |
1.67 |
1.51 |
1.89 |
1.86 |
1.78 |
200 |
Government |
1.34 |
1.35 |
1.41 |
1.3 |
1.33 |
100 |
Total Capacity Checks/day |
500 |
300 |
300 |
200 |
200 |
Question 1a. What is the minimum cost that can be achieved and meet requirements?
A. $2680 B. $2798 C. $2579 D. $2783 E. None of the above
Question 1b. From concern about a site processing a large number of one type of check, a limit of 250 transactions per type of check for each site is being considered. What is the minimum increase in cost due to this added constraint? A. $20 B. $15 C. $10 D. $5 E. None of the above
Formulation in Excel:
Solver inputs:
Solution:
Site1 | Site2 | Site3 | Site4 | Site5 | Total | Demand | |
Personal | 100 | 300 | 0 | 100 | 200 | 700 | 700 |
Payroll | 400 | 0 | 0 | 0 | 0 | 400 | 400 |
Draft | 0 | 0 | 200 | 0 | 0 | 200 | 200 |
Government | 0 | 0 | 0 | 100 | 0 | 100 | 100 |
Total | 500 | 300 | 200 | 200 | 200 | ||
Total Capacity | 500 | 300 | 300 | 200 | 200 | ||
COSTS | Site1 | Site2 | Site3 | Site4 | Site5 | ||
Personal | 2.55 | 2.35 | 3.22 | 2.85 | 2.25 | ||
Payroll | 1.45 | 1.35 | 2.1 | 1.95 | 1.84 | ||
Draft | 1.67 | 1.51 | 1.89 | 1.86 | 1.78 | ||
Government | 1.34 | 1.35 | 1.41 | 1.3 | 1.33 | ||
Total cost | 2783 |
So, answer to 1A is 2783
-----------------------
1B
Add the following constraint to solver:
Solution:
Site1 | Site2 | Site3 | Site4 | Site5 | Total | Demand | |
Personal | 250 | 150 | 0 | 100 | 200 | 700 | 700 |
Payroll | 250 | 150 | 0 | 0 | 0 | 400 | 400 |
Draft | 0 | 0 | 200 | 0 | 0 | 200 | 200 |
Government | 0 | 0 | 0 | 100 | 0 | 100 | 100 |
Total | 500 | 300 | 200 | 200 | 200 | ||
Total Capacity | 500 | 300 | 300 | 200 | 200 | ||
COSTS | Site1 | Site2 | Site3 | Site4 | Site5 | ||
Personal | 2.55 | 2.35 | 3.22 | 2.85 | 2.25 | ||
Payroll | 1.45 | 1.35 | 2.1 | 1.95 | 1.84 | ||
Draft | 1.67 | 1.51 | 1.89 | 1.86 | 1.78 | ||
Government | 1.34 | 1.35 | 1.41 | 1.3 | 1.33 | ||
Total cost | 2798 |
So,
The cost increases by 2798 - 2783 = 15