Following considerations in completing service calls:
- Parts needed for most repairs are kept in a storage room at the complex
- For unusual problems, a trip to a local supply house is necessary
- If the part is available on site, the maintenance person finishes one job before checking on the next complaint
- If the part is not available on site and any other calls have been received, the maintenance person will stop by the other apartment(s) before going to the supply house
- It takes approximately 1 hour to drive to the supply house, pick up a part, and return to the apartment complex.
- Past records indicate that, on approximately 10% of all calls, a trip must be made to the supply house.
The time required to resolve a problem if the part is available on site varies according to the following:
Following considerations in repairing the problem:
- It takes approximately 30 minutes to diagnose difficult problems for which parts are not on site
- Once a part has been obtained from the supply house, it takes approximately one hour to install the new part.
- If any new calls have been recorded while the maintenance person has been away picking up a new part, these calls will wait until the new part has been installed.
The cost of salary and benefits for a maintenance person is $20 per hour. Management would like to determine whether two maintenance people should be working on weekends instead of just one. It can be assumed that each person works at the same rate.
Discussion questions:
- Use simulation to help you analyze this problem. State any assumptions that you are making about this situation to help clarify the problem.
- On a typical weekend day, how many tenants would have to wait more than an hour, and how much money would the company have to credit these tenants?
Statement of the problem:
The group wants to know if the 1 hour waiting time is labor and cost efficient during weekends.
Assumptions:
- Frequency of calls
- Calls are made during weekends
- Parts are available on site since only 10% of calls need a trip to the supply house.
- 24 hours of continuous repair
- Work shift does not affect repair work
- No rent deduction if worker arrives exactly one hour of call. Rent deduction will only start on the first minute i.e. 9:01
- For simplicity, time of work starts 12:00 AM.
- With back-up worker during peak hours for a lower rate per hour
Quantitative methods used to solve the problem:
Microsoft Excel’s Random Function is used to simulate repair works in the apartment. From the random numbers, it generates the time of call and the time of repair from the given probabilities by using the VLOOKUP command. The time that the worker can start and the waiting time of callers are then determined to know if an additional worker is needed.
Alternative Course 1: One Worker
One worker service cost = 18.5 working hours x $20 per hour
= $370.00
Total Deductions from five callers of Calls 9 to 12 and 14 = $60.00
Total cost = Service cost + deduction from rent
= $370.00 + $60.00
= $430.00
Alternative Course 2: Two workers
Worker A service cost = 18.5 working hours x $20 per hour
= $370.00
Worker B service cost = 5 working hours x $10 per hour
= $50.00
Worker B will be on per call basis and needed only during the peak hours like from five callers of Calls 9 to 12 and 14 to avoid the rent deduction of $60.00.
Total cost = A & B service Cost
= $370 + $50.00
= $420.00
Ethical Consideration:
- Quality of service of the repairman might be compromised because of the pressure to finish early and quickly attend to the next caller within an hour to avoid the $10 rent reduction which the management might deduct from their salaries.
- Student’s repair needs differ with the other students. There should be a qualification on what types of repairs that is included in the 1 hour marketing strategy.
- Regular maintenance must be done to ensure the good working condition of the air condition and plumbing. Air pollution can be an effect of inefficient air condition machines. Proper drainage must be maintained to prevent leakage of the waste pipes.
- If management decided that two maintenance workers are needed, the new worker will probably be a contractual employee because of the seasonal demand of repair work during the summer
- Continuous repair work may also affect the efficiency of the worker. Stamina may deteriorate due to over work / fatigue.
- Working on nightshift/graveyard shift should have a night differential pay in accordance with labor law.
Conclusion:
Since the additional worker will be idle for 12 hours with a cost of $240, one worker is still enough per work shift and the $60 deduction cost less.
