Like human beings machines suffer from fatigue and exhaustion. Machines, buildings and other plant facilities deteriorate because of wear and tear, because of use, overuse, misuse, vibrations, cold and hot fumes, etc. If “diseased” machines are not cured in time or before time, they will become inefficient, which will lower the quality and quantity of production. In fact, the maintenance of machines is essential for the overall efficiency of business. Increased mechanization has made a proper maintenance of machines, one of the imperatives for the success of an enterprise. It is for this reason that all big industries have a well designed programme for timely and adequate maintenance of various plant facilities. Medium-size and large-scale industries have a full-fledged maintenance department, known as the plant engineering department, whose main job is to ensure that the entire plant is in perfect working order.
Types of Maintenance
Maintenance can be of two types:
- Preventive maintenance;
- Corrective or repair maintenance.
In preventive maintenance, precautionary action is taken before the problem arises. If it is apprehended that a certain part of the machine will be shortly worn out, the immediate replacement of that part before it is actually worn out is called preventive maintenance. Preventive maintenance involves a definite programme of routine inspection, cleaning, and servicing of parts and machines.
The best example of preventive maintenance is provided by the automobile. Here, regular servicing after 1,000 kilometers, regular greasing, tuning and oil change after a definite period ensure the smooth functioning of the vehicle.
In industries, the problem of maintenance is very acute. It is always desirable, therefore, to identify the potential source of the trouble well in advance so that timely corrective action may be taken.
But the degree of attention to be paid to the need for maintenance and replacement varies from company to company. For example, the protection required in plants manufacturing poisonous gases is different from the one required in plants manufacturing software. The attention given to a blast furnace is different from that given to the fabrication of wheelbarrows. If interruptions in production are not of a serious nature and if a breakdown can be quickly dealt with, the intensity of preventive maintenance can be relaxed. But in industries like pesticides, chemicals and fertilizers, a high degree of excellence in maintenance is required.
Corrective or Repair Maintenance:
As a rule, depreciation in plants, machinery and other equipment takes place because of the passage of time, weather effects and accidents. Worn-out machinery needs repairs and replacement from time to time. Corrective maintenance is concerned with eliminating production bottlenecks by timely repairs or replacement of worn-out parts. Repair maintenance may call for the disassembly of equipment and the detection of malfunctioning, the repair or replacement of broken parts and then a check to make sure that the machinery or equipment functions efficiently.
This refers to the substitution of old equipment by new. It is generally needed because of the following reasons:
- Natural decay;
- Technological change;
- New demand;
- Improved working.
However, much emphasis is now placed on scheduled replacement because most of the machines/plants require certain parts to be replaced after the expiry of a definite time period.
The top management is not concerned with the petty matters of maintenance and replacement. However, to maintain the optimum efficiency of the plant, senior executives furnish guidelines to their subordinates for maintenance and replacement, i.e., when to slow down replacement or push it, what level of maintenance is required and to what extent.