GMS 401 – Chapter 15- Supplementary
Maintenance: All activities that keep facilities and equipment in good working order so that a system can
perform as intended.
Goal: keep production system in good working
order at minimum cost.
Avoid production disruptions
Maintain high quality and safety
Avoid missed delivery dates
breakdown (emergency) maintenance dealing
with breakdowns (repair/ replacement) only
after they occur.
Preventive maintenance : avoiding
breakdowns through a program of
lubrication, bolt tightening, cleaning,
inspection, and replacement of worn parts.
Managers usually schedule preventive maintenance using some combination of the following:
1. The result of planned inspections that reveal a need for maintenance
2. According to the calendar (passage of time)
3. After a predetermined number of operating hours (or miles for vehicles
The age and condition of equipment, the degree of
technology involved, the type of production
process, and similar factors enter into the decision
of how much preventive maintenance is desirable.
Given preventive maintenance (PM) interval L, if a breakdown occurs before L, then a breakdown
maintenance cost will be incurred, and the machine will be repaired and the next time between breakdowns
(TBB) will start. On the other hand, if there is no breakdown before L, then a PM cost will be incurred at
time L. We determine L so that expected cost of each consequence is equal, i.e.,