What is the best method for our Preventive Maintenance activities
A Question:a
What is the best method for our Preventive Maintenance activities? a
During preventive maintenance system implementation in a factory, I received a lot of questions and criticisms after new work procedures explanation for personnel. “How can we follow this procedures when there is an emergency work?”; it was their main question because: as per new procedures, operation unit supervisors should send their maintenance requests to maintenance department and technical unites were receiving work orders from that department. a
For this regard I explained that “there is one shortcut for urgent causes and production line emergency shutdowns which as per this shortcut, operation units have permission for direct connection to technical units, and technical units should have urgently acting in this causes. But all the history of work should be recorded and transferred to maintenance department after work finishing. a
“As per actual situation, we should used only this shortcuts of procedures for our job!” one of technicians said. a
Maybe he was true when all of their activities were only emergency causes as per previous work procedures. Those procedures mentioned that factory equipment should operate till breakdown happening and only in the breakdown causes the work of technical group was starting. a
“Zero present of breakdowns is one of the main goals for preventive maintenance system which this goal is achievable as per Toyota Company experience for several years” I said to them. a
But do you think, there is no any activity for maintenance units in
I released this experience as per article introduction because some one asked me “Reducing of breakdowns can be a goal for a preventive maintenance system?!” a
Operation conditions and operator skills, technical supports, equipment and facilities, logistic and procurement procedures and efficiency and maintenance system abilities can be affected on factory and machines productivity and reducing breakdowns and emergency shutdowns and also affected on quality of work and products. But there is an important point: “Which quantity and quality of these services could be efficient with optimum status?!” a
For example, employ maintenance experts and maintenance special tools and equipment for an small factory with very simple machine can not be economy which the cost of breakdowns and opportunity for this factory will be lower that the cost of maintenance services, also if there is a local market and easy access for parts and materials beside a factory, it will not be economy if that factory goes for a wide department of logistics. But of course, specialist and expert personnel in maintenance department, special equipment and tools for maintenance and a great system for maintenance are necessary and economy for a high technology factory with special machines. For this kind of industries, the cost of breakdowns and the cost of production line shutdowns and opportunity are very high and maintenance services should be equal with needs. a
What is the best method for our Preventive Maintenance activities? a
Before answering to this question, I explain my definition of PM as below: a
“All planned activities (Inspections, Services, Replacements and Repairs) along with operation situations for keeping machines in normal situation and prevent of faults and breakdowns is PM.” a
I don’t think there is no difference between Predictive maintenance (PDM), Total productive maintenance (TPM) , Condition monitoring(CM), Reliability (RCM),…. And PM for comparing but they are different methods for preventive maintenance. a
Preventive maintenance, especially in the field of inspection has different levels of activity which they are based on five human senses and continue to high technology equipment and tools such as vibration analyzers or oil analysis and data analysis systems. a
Difference of this methods and levels is distance between fault recognizing and breakdown. If machine fault recognizing with human visual or hearing inspection is very near to breakdown but result of high technology inspections shown the fault when it is just starting and machine is very far from breakdown situation. The benefit of this method of inspection is having enough time for planning and preparing maintenance work necessaries and also removing the fault with lower cost and lower activity along with high reliability for machine operation. a
But after this introduction now we refer to main question which it is: “What is the best method for our Preventive Maintenance activities? “ a
Best method for your maintenance activities is related to which kind of industry and machine you are maintaining. For selecting the method and level of maintenance, at the first you should calculate the cost of breakdowns and emergency maintenance plus opportunity cost for production then estimate the cost of maintenance level which you want to used, if you compare these costs then you will understand is this level of maintenance suitable for your machines or not. With comparing costs of breakdown maintenance with costs of different levels of maintenance you can find optimum point and best level of maintenance for your industry. a
For example, maybe high level of maintenance with maintenance analyzer equipment could not be economy for a small factory with simple machines but maybe this level of maintenance is not enough for a high-tech industry with special machines. a
Reza Tajvidi
www.mwm1.blogfa.com
September 2009


Different Strategies of Maintenance
﹖to be considered by a maintenance expert