All landmark achievements leading to distinctive & noteworthy techniques or technology have been a result of highly compelling needs, & such accomplishments have, more often than not, the capability of transforming entire Systems & processes in a variety of fields.
“Operations Research” for instance, is a discipline, which deals with the application of advanced analytical methods to arrive at better decisions quickly. This is an offshoot of methodologies developed by military planners during World War-II. The technique has thereafter, made substantial and everlasting in-roads into industries ranging from petro-chemicals to airlines. Numerous inventions like GPS, Nuclear Technology, Night Vision devises, duct tapes, Internet, which are so commonly used in daily life, have their origins to their development to meet the needs of the Armed Forces.
Maintenance Management & Maintenance Philosophies likewise are no different and have travelled a long distance since the First World War, to the present state of art, and the credit of the development can be, to a large extent, claimed by the commercial aircraft industry. The progress of the maintenance philosophy is depicted diagrammatically below, highlighting major milestones crossed on the way.
- The Pilots & Mechanics were the decision makers
- Banked on experience to work out maintenance strategies
- Commercial Airlines became increasingly popular
- Flight Safety Consciousness – an Important Factor
- OEMs became the focal point in maintenance programme development
- Hard Time (HT) became Order of the day
- FAA & Fleet Owners examined the efficacy of system adopted.
Findings: - Scheduled overhaul had little effect on overall reliability
- Many items do not render themselves to HT Scheduled Maintenance
- Led to next stage; “On Condition” maintenance. Periodic checks to ensure, item removed before actual failure.
- Led to un-acceptable increases in downtime; Un-profitable proposition
- MSG -1 established
- Group of decision makers enhanced
- Maintenance processes developed to utilise decision logics of both, HT & OC
- MSG 1 upgraded to MSG -2
- Used “Condition Monitoring” to generate maintenance tasks
- Applied to 3 different types of aircraft and the study continued
- MSG -2 upgraded to MSG -3 after identifying shortcomings of MSG -2.
MSG -3 included following improvements:
- Separated Safety & Economic related items
- Defined adequate treatment of hidden functional failures
- Activities assessed at System level rather than component level; a new TOP – DOWN approach
The approach of MSG -3, which is on a continuous path of refinement, made possible with ever- evolving technological advances, demonstrates that if functional failure of a system has no effect on operational safety, or has no significant economic significance, there was no need for a routine maintenance activity.
One point that stands out from this historical review is, that there is a tendency to continuously add on maintenance tasks / actions in the maintenance schedules making the entire process un-wieldy with a pseudo sense of enhanced reliability. A pragmatic view of all such inclusions needs to be taken to ensure we attend to critical areas with our exact purpose in mind. That will help retain a lean and efficient maintenance function.
