محاضرات في هندسة الصيانة

1. Introduction to Maintenance
Dr. Munthear Alqaderi
munthear@gmail.com

2. Inspection
Report

3. Maintenance
Preventive M.
“To Keep”
Corrective M.
“To Restore”
A facility to an acceptable standard
What is Maintenance?

4. Maintenance Works
Planned
≥ 70 %
Unplanned
≤ 30 %
Minor repairs
≤ 20 %
Breakdown
≤10 %
PM
≥ 50 %
overhaul
≥ 20 %
Typical Work (man-hour) distribution in engineering industries

5. Minor repairs
≤ 10 %
Breakdown
≤ 5 %
PM
≥ 70 %
Overhaul
≥ 15 %
Maintenance Works
Planned ≥ 85 % Unplanned ≤ 15 %
Typical work effort (man-hour) distribution in critical industries (such as gas,
oil, steam , power equipment)

6. Maintenance Costs
Maintenance
Commitment
Cost
PM Cost
Total Maintenance Cost
Breakdown Cost
Optimal

7. Determining the Size of Repair Crews
 Problem:
 A factory has 200 machines and the maintenance
engineer supervises the repair crews who repair
malfunctioning machines. The maintenance policy is
to repair the broken down machine and bring back in
production within 2 hours on the average. If average
breakdown rate is 3.5 machines/hour and each repair
crew can repair 0.25 machine per hour on the
average. How many repair crews are required ?

8. Solution
The formula for average repair rate () is
1
ts = ---------- or  =  + 1/ ts
 - 
Where  = repair rate
 = arrival rate of malfunctioning machines
ts = average time arrivals in the system
Required average repair rate
 = 3.5 + 1 / 2 = 4 machines / hour
No. of Crews =   machines/hour a crew can repair
= 4  0.25 = 16 repair crews required

9. Types of Maintenance
MAINTENANCE
UNPLANNED
MAINTENANCE
(REACTIVE)
BREAKDOWN
EMERGENCY
PLANNED
MAINTENANCE
(PROACTIVE)
CORRECTIVE
MAINTENANCE
REMEDIAL
DEFERRED
PREDECTIVE
MAINTENANCE
CONDITION -
BASED
STATISTICAL
- BASED
PREVENTIVE
MAINTENANCE
ROUTINE
RUNNING
DESIGN - OUT
ENGINEERING
SERVICES
WINDOW
IMPROVEMENT
MAINTENANCE
SHUTDOWN
CORRECTIVE
SHUTDOWN
PREVENTIVE
SHUTDOWN
IMPROVEMENT
Shutdown Maintenance
OPPORTU-
NITY

14. Maintenance Strategy
Implementation
Breakdown
Preventive
Predictive
1 2 3 4 5 6 7 8 9 10
Year
100%
80%
60%
40%
20%
0%
Percentage of Maintenance Time by Strategy