Service vs. maintenance

There is a noteworthy distinction between the activities of “maintenance” on one hand and “service” on the other. Maintenance is a partial or total renewal of an item. Maintenance reduces the physical age of an item or can even “zero time” the item by rejuvenating some or all of its components. By contrast, Nowlan and Heap describe “service” as “activities necessary for achieving the design life of the asset”. Service is something that we have to do, operationally, if we wish to achieve the item’s inherent reliability. Service should not, generally speaking, in RCM or LRCM, be the object of intense debate or scrutiny by reliability or maintenance engineers.

We note the difference between service and maintenance, primarily to address a frequent confusion of priorities for reliability engineering studies. Generally speaking, maintenance engineers should not spend significant energy second guessing the manufacturers’ service recommendations. Those are usually a good starting point and can be taken at face value. Rather, reliability engineers should target their reliability studies towards the improvement of maintenance strategies. To this end, they should spend the bulk of their time in the following activities:

1. managing the RCM knowledge base,
2. managing the relationships (reference links) between the RCM knowledge base and the work order database,
3. generating samples for reliability analysis,
4. performing reliability analysis,
5. reporting the recommendations derived from their analyses,
6. monitoring the performance of all of the above (low level or “leading” KPIs), and
7. monitoring the results of implementing those recommendations (high level or “lagging” KPIs).

Service tasks often represent opportunities for effective CBM measurements. In this respect they justify scrutiny by the RCM analysts.

© 2011, Murray Wiseman. All rights reserved.