Prof. O.P. Gandhi
ITMMEC, IIT Delhi
Maintenance :Maintenance is a set of organised activities that are carried out in order to keep an item in its best operational condition with minimum cost acquired. It can also be defined as the combination of all technical and administrative actions, including supervision actions, intended to retain an item in, or restore it to, a state in which it can perform a required function
All the activities of the management that determine the maintenance objectives or priorities (defined as targets assigned and accepted by the management and maintenance department), strategies (defined as a management method in order to achieve maintenance objectives), and responsibilities and implement them by means such as maintenance planning, maintenance control and supervision, and several improving methods including economical aspects in the organization.
The term ‘maintenance’ means to keep the equipment in operational condition or repair it to its operational mode. Main objective of the maintenance is to have increased availability of production systems, with increased safety and optimized cost. Maintenance management involves managing the functions of maintenance. Maintaining equipment in the field has been a challenging task since the beginning of industrial revolution. Since then, a significant of progress has been made to maintain equipment effectively in the field. As the engineering equipment becomes sophisticated and expensive to produce and maintain, maintenance management has to face even more challenging situations to maintain effectively such equipments in industrial environment. This brief lecture on maintenance management includes maintenance strategies, functions of maintenance department, maintenance organization and elements of maintenance management.
MAINTENANCE STRATEGIES OR OPTIONS
A maintenance strategy or option means a scheme for maintenance, i.e. an elaborate and systematic plan of maintenance action. Following are the maintenance strategies  that are commonly applied in the plants.
* Breakdown Maintenance or Operate to Failure or Unplanned Maintenance * Preventive or Scheduled Maintenance
* Predictive or Condition Based Maintenance
* Opportunity Maintenance
* Design out Maintenance
The equipment under breakdown maintenance is allowed to run until it breaks down and then repairing it and putting back to operation. This strategy is suitable for equipments that are not critical and have spare capacity or redundancy available. In preventive or scheduled Maintenance, maintenance actions such as inspection, lubrication, cleaning, adjustment and replacement are undertaken at fixed intervals of numbers of hours or Kilometers. An effective PM program does help in avoidance of accidents. Condition monitoring (CM) detects and diagnoses faults and it helps in planned maintenance based on equipment condition. This condition based maintenance strategy or predictive maintenance is preferred for critical systems and for such systems breakdown maintenance is to be avoided. A number of CM techniques such as vibration, temperature, oil analysis, etc. have been developed, which guide the users in planned maintenance . In opportunity maintenance, timing of maintenance is determined by the procedure adopted for some other item in the same unit or plant. In design out maintenance, the aim is to minimize the effect of failures and in fact eliminates the cause of maintenance. Although it is an engineering design problem, yet it is often a responsibility of maintenance department. This is opted for items of high maintenance cost that are due to poor maintenance, poor design or poor design outside design specifications. It may be mentioned that a best maintenance strategy for each item should be selected by considering its maintenance characteristics, cost and safety.
References: 1. Kelly, Anthony, “Managing maintenance resources”, Butterworth-Heinemann, 2006.
2. Collacott, R.A., “Mechanical fault diagnosis”, Chapman and Hall, 1977.
3. Levitt Joel, “Handbook of maintenance management”, Industrial Press, 1997.
4. Wilson Alan, “Asset maintenance management”, Industrial Press, 2002.
5. Tery Wireman, “Developing performance indicators for maintenance”, Industrial Press, 2005.
Please join StudyMode to read the full document