Maintenance and Reliability

1
Maintenance and Reliability

• Ross L. Fink

2
Maintenance

• All activities involved in keeping a systems
  equipment in working order

3
Reliability

• The probability that a machine part or product
  will function properly for a specified time under
  stated conditions

4
System Reliability - Components in Series
100 80 60 40 20 0
n1
n10
Reliability of the System (Percent)
n50
n100
n300
n400
n200
100 99
98 97
96
Average Reliability of all Components (Percent)
5
System Reliability

• RsR1R2R3Rn
• Where,
• Rs System reliability
• Ri reliability of component i

6
Reliability Tactics

• improving individual components
• providing redundancy

7
Redundancy

• The use of components in parallel to raise
  reliabilities
• Example, what is the effective reliability of two
  components used in parallel with reliability of
  .90?
• .90 (1-.90).90).99

8
Mean Time Between Failures (MTBF)

• FR(N) number of failures during a period of
  time
• MTBF1/FR(N)

9
Maintenance

• Preventive Maintenance
• A plan that involves routine inspections,
  servicing, and keeping facilities in good repair
  to prevent failure
• Breakdown Maintenance
• Remedial maintenance that occurs when equipment
  fails and must be repaired on an emergency or
  priority basis

10
Total Productive Maintenance

• TQM applied to Maintenance
• Components
• Predictive maintenance
• Cleaning the machines
• Creating standards on the equipment for cleaning,
  lubrication, and daily checks
• Collecting data on downtime
• Creating equipment improvement teams
• Creating TPM area coordinators