There are many ways in which Maintenance is defined like
“Activities required to conserve as nearly, and as long, as possible the original condition of an asset or resource while compensating for normal wear and tear. “
“Actions necessary for retaining or restoring an equipment, machine, or system to the specified operable condition to achieve its maximum useful life. It includes corrective maintenance and preventive maintenance.”
How to derive activities or actions? A new definition of maintenance which is given here will help in penetration into ‘Why’ of maintenance.
“Maintenance is an activity of normalization of equipment or a body towards the active and passive services performed by it”.
- Normalization: During the service, the equipment and its part converts and transfer energy and thus undergoes self-change. There is need to bring it back to its normal state.
- Active: Active service is such in which the equipment converts energy from one form to another such as oven, motor, diesel engine, electric lamp etc. In fact, it is the efficiency of activity which determines the maintenance need and also when the parts are rubbing continuously such as current collection, rail wheel interaction or intensive duty cycle like tap changer of the locomotive.
- Passive: Passive service is such in which the body undergoes chemical changes due to aging, environment, dust etc. Painting, replacement of rubber gaskets, cleaning etc. comes in this category.
Maintenance is a thus a function of level of active and passive services performed by any equipment.
Maintenance = f (a , p)
Active service shall be sub-divided based on duty cycle. The duty cycle will certainly be different for an equipment in different application and therefore, the maintenance need also e.g. panto-sweeping , the GR duty cycle of coaching and freight services, auxiliary contacts, BL Switch etc.
An equipment may have 10 auxiliary contacts, of which the duty cycle of 1 may be very intense, 2 each intense and normal and balance occasional. In such circumstances, maintenance input shall also be in three categories. Very Intense duty components shall be identified with a specific color to help the maintenance engineers to identify and monitor its functioning more carefully.
Environmental studies shall be carried carefully for designing maintenance need towards passive services. Environmental study means the environment of temperature, dust (metallic or non-metallic), humidity and exposure to rain water etc. in which a specific equipment operates, so that special care is during design or specially advised to maintenance man.
It is important to identify special environmental condition encountered by a specific equipment/component depending upon its location and not the conditions in general.
Maintenance engineer shall work out the active and passive services in consultation with Design engineer to table the maintenance need.