The performance of a machine is not deteriorated by long term usage provided its maintenance is done properly.
Total Productive Maintenance (TPM):
Total productive maintenance is a novel approach for maintaining machines which improves the efficiency of machines, eliminates breakdown and promotes independent maintenance by operators in the daily activities. TPM is not a specific maintenance policy; it is a culture, a philosophy and an attitude towards excellence in maintenance. Industrial experience proves that through implementation of TPM in industries, production has increased by 50%, machine downtime is reduced by 15% and generation of defective products is overcome by 80%. Apart from this, TPM also offers various intangible benefits such as concept of team work, increases morale safety and we have spare time to increase intellectual capabilities and potential to face competition and challenge in present era.
Since business has global influence, two of the customer's basic requirements are Quality and Timely delivery. The change in the concepts of how to achieve world class quality has been due to the theories and techniques propagated by modern experts.
Types of Maintenance:
1. Scheduled Maintenance
With the erection & commissioning of plant, machine manufacturers' are providing manual and various check lists which are based upon 'fixed running time ' or 'fixed period'. These check list to be followed by maintenance team on daily , bi-weekly , weekly , fortnightly , monthly , half -yearly , annual maintenance basis. We can take an example that working of a particular machine depends between 0 degree and 360 degree of cycle. Many parts and motion have been synchronized in one running cycle.
If two components should have distance between 9 mm and 9.5 mm, we observe that during disturbed settings, machine can work smoothly below or beyond these degrees. What is happening with other components of machine below 9 mm or beyond 9.5 mm is the factor to be determined. This is the reason we need to correct the settings during scheduled maintenance as a precautionary measure. All the findings during scheduled maintenance must be documented in a check list for future reference and status to check effectiveness at any point of time.
We can take an example of Textile Weaving Unit having Dyeing and Sizing Range with Steam Boiler.
In this way, we can see that timely action plan and implementation is important after analysis of findings during scheduled maintenance. We should not forget that only cleaned machines can be lubricated well.
2. Predictive Maintenance:
If very short preventive maintenance interval is selected, the machine will be overhauled unnecessarily with consequent loss of production and possible human errors during dismantle of sophisticated assembly. We can see that equipment seldom deteriorates in few minutes, followed by a sudden failure. Predictive maintenance is an important step which is performed by experienced person on the actual working condition of the machine. Some of the criteria for predictive maintenance are given below:
3. Preventive Maintenance:
This process involves re-checking of components in similar machines if there is a breakdown in one machine. If we keep a strict follow up in preventive maintenance, value losses due to low production or bad quality can be drastically reduced in a plant. This also helps in avoiding excessive spare parts inventories. It is very important that we must keep appropriate tools (Spanners, Allen Key Sets, Gauges, Torque Spanners etc.) to avoid improper fitting of nuts and bolts in equipment.
During machine maintenance we can use different sign boards to prevent accidents.
We can conclude that by maintaining equipment and machineries well, industries can consistently deliver effective outputs. In this way we can achieve plant safety, optimum efficiency, time saving in different processes, long-term savings in cost and commitments. Industries that carry out good follow up on maintenance always attract the customer by full utilization of machines as well as housekeeping.
1. Production / Operations Management by L.C. Jhamb
2. World Class Manufacturing by Kamalakar Mutalik
3. Classification of Maintenance Policies by Chowdhury and Farkas Vol. III / 1985
4. Implementing Total Productive Maintenance by Nakajima Seiichi Vol VI / 1986
5. Tsudakoma Air Jet Loom Maintenance Manual
Mr. Pradeep Kulshrestha is Head of Incubation Centre , Ahmedabad Textile Industry's Research Association (ATIRA)