2. INTRODUCTION:
Maintenance is the process of keeping the machine and equipment in good working
condition so that the efficiency of machine is retained and its life is increased.
The technical meaning of maintenance involves functional checks, serving, repairing or
replacing of necessary devices, equipment, machines, and buildings in industrial
business. Government and residential installations.
"Plant maintenance is a combination of actions carried out by an organization to
replace, repair, and service the machineries, components or their groups in a
manufacturing plant, so that it will continue to operate satisfactorily“
The objective of maintenance is to maximize the performance of productive resources
of an organization by ensuring that these resources perform regularly and efficiently.
This is achieved by preventing the breakdown and failures and by minimizing the
production loss.
4. PLANNED MAINTENANCE:
Planned maintenance refers to any maintenance activity that is planned and
scheduled in advance.
The aim of planned maintenance is to reduce downtime and increases the
production.
Planned maintenance incorporates all the functions like planning, scheduling,
dispatching, recording, analysis and controlling.
Then a planned work cycle may be represented as shown in Figure:
6. SCHEDULED MAINTENANCE:
The aim of scheduled maintenance is to minimize breakdown.
This system prmides for inspection, overhauling, lubrication, and servicing of
certain machines at predetermined dates.
Scheduled maintenance is any repair and service work performed within a set
timeframe.
For example, replacing of an air filter in an engine, washing of water tank filter,
overhauling of machines, cleaning of tanks and white washing of buildings are
normally done in this manner.
7. ADVANTAGES OF SCHEDULED
MAINTENANCE:
lt reduces the down time during repairs.
The breakdown is minimized and machines run at a higher level of efficiency.
Predetermination of date of commencement of work ensures to plan the work load and
distribution of maintenance work force for balanced attention of all equipment.
8. PREDICTIVE MAINTENANCE:
This is a method in which the service life of important part is predicted based on
inspection or diagnosis, in order to use the parts to the limit of their service life.
Compared to periodic maintenance, predictive maintenance is condition based
maintenance.
It helps to minimize downtime, reduce costs, and optimize maintenance schedules.
The main advantage of such a procedure is to provide means to inspect the troubles of any
internal part without disassembly.
But predictive maintenance cannot be applied in general, although it minimizes the risk of
failure and reliably extends the service life.
9. PREVENTIVE MAINTENANCE:
This is one of the oldest maintenance systems being practiced in industries.
Preventive maintenance (PM) is the planned maintenance of plants and equipments
in order to prevent or minimized breakdowns and deprecation rates.
A preventive maintenance will not only prevent breakdown or reduce operating
costs but also will improve output or quality of product.
The basic principle involve in this system is "prevention is better than cure".
10. ADVANTAGES OF PREVENTIVE
MAINTENANCE:
Less production downtime, because of fewer breakdowns.
Major repairs and repeatative repairs can be avoided.
Product rejection comes to a minimum level, minimizing the chances of spoilage.
Provide better quality control facilities.
Provide greater safety and protection to the workers.
11. UNPLANNED MAINTENANCE:
The unplanned procedures permit failure to take place before any maintenance work
is done. It may be termed as an "Emergency Maintenance”.
It involves less direct maintenance cost but enhances the probabilities of down time
of machineries.
Generally an unplanned system may be employed in small scale industries, where a
planned maintenance is not economically viable.
12. BREAKDOWN MAINTENANCE:
In a breakdown maintenance system, maintenance work such as repairing,
replacement etc. are performed only when breakdown occurs.
The equipment is allowed to run without much routine attention, till it actually
breaks down and fails to perform its function.
This system of maintenance system can only be suitable for small scale industries,
because of its less direct cost involvement.
For example, an electric motor of a machine tool will not start, a belt is broken etc.
13. ADVANTAGES OF BREAKDOWN
MAINTENANCE:
Cost Saving: when applied to the right equipment, this approach can
reduce the cost of unnecessary maintenance.
Simplicity: Breakdown maintenance requires no advance planning or
scheduling. Maintenance is performed only when a failure occurs.
Breakdown maintenance can be a practical approach for equipment where
failure doesn’t impact productivity or safety.
14. DISADVANTAGES OF
BREAKDOWN MAINTENANCE:
Increased cost due to unplanned downtime of equipment.
Reduction of output.
Increased chances of accidents and less safety to both workers and
machines.
The spoilage of materials is increased due to production of more defective parts.
15. CONCLUSION:
To ensure effective implementation of activities, it is
important that the production facilities need to be
maintained in good working condition.
Reduces cost, machinery breakdown etc.
Therefore maintenance management is an important
aspect for any organization
