Jasper Coetzee

In any challenging management situation, the fight is halfway won if one knows where to start.  The same is obviously true in maintenance.  The problem is that most maintenance managers do not know where to start. 

In the previous Maintenance Scrap (11 April 2011), the accent was on driving Maintenance Improvement through strategic improvement.  Now, that is one of the ways to rectify a bad maintenance situation; in actual fact it is the best way, as everything that you do are driven from well thought through strategies.

However, when thinking about what approach to the technical side of the maintenance business will produce the best results for the equipment of the business, there are a few possible complementary answers.  These include Reliability Centred Maintenance (RCM) for designing a well-founded scientifically sound maintenance plan, and Root Cause Analysis (RCA) to wean out those critical repetitive failures.

Another method for focussing your maintenance effort on the right issues comprises a risk-based approach towards determining what maintenance situations (typically failures) should be addressed with high priority.  This is the method that I want to discuss in this issue of Maintenance Scraps.  If utilised dilligently, it can produce phenominal results.

The risk-based approach can also be used to determine what equipment (and which of their failure modes) should be subjected to formal RCM analysis, and also what problems should be subjected to RCA analysis.  But, further to this, risk-based prioritisation also serves to identify those areas that should be subjected to scrutiny regarding the appropriateness of the supplied logistical support, the procurement process, and even the design of the parts involved. 

Risk-based analysis consists of the analysis of the maintenance costs and the production income of your business.  Its purpose is to to identify all the major contributors to high maintenance cost and/or low production income.  As such, it identifies all those items that causes maintenance to have high negative impact on the profit of the business.  Such items are typically sub-systems and/or components that (i) fail with high frequency or (ii) of which the repair cost after failure are very high or (iii) of which the failure have a high negative production impact.  The cause of high cost risk of these items must then be identified and removed.

The idea is to arrange the various cost risks to the business on a high to low scale, and then start removing these risks one by one through dilligent application of solid engineering methods.  

A risk consists of two dimensions, the impact (cost) of the event, and the frequency at which it occurs.  Typical high risk events consist of three types:

• Those with a high impact and low frequency. They are the critical risks that one would endeavour to remove summarily (or at least reduce their impact). 
• Those with medium impact and medium frequency. They are risks for which both the impact and the frequency should be reduced if possible, with the impact reduction being of higher priority than the frequency reduction.
• Those with high frequency and low impact.  They are the risks that are more a nuisance that anything else.  Frequency reduction is the method used, but only if both the classes of risks listed above are already reduced as far as possible.