Maintenance and Reliability Ross L. Fink

Maintenance  All activities involved in keeping a system’s equipment in working order

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

System Reliability - Components in Series Average Reliability of all Components (Percent) Reliability of the System (Percent) n=1 n=10 n=50 n=100 n=200 n=300 n=400

System Reliability  R s =R 1 *R 2 *R 3 *…*R n  Where,  R s = System reliability  R i = reliability of component i

Reliability Tactics  improving individual components  providing redundancy

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

Mean Time Between Failures (MTBF)  FR(N) = number of failures during a period of time  MTBF=1/FR(N)

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

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