Critical Spares Analysis - What's the Problem?

We recently completed a project for a mining client where the brief was to review critical spares. They had previously identified critical equipment. The manager assumed that the critical spares associated with his equipment would be in a register and the spares were being managed by supply. 

We found that the register was not only out of date, but was incomplete, inaccurate and in some cases lacked sound logic around criticality. We also found that personnel did not understand what constituted a critical spare. 

Site expressed that they did not have enough critical spares, that those which were catalogued would probably not be in stock or may not be in good working order. The general perception was that the risk of downtime because of poorly managed critical spares was high. 

Maintenance personnel developed this idea because in the past, even basic maintenance, repair and operational (MRO) spares had cost them downtime which they felt should have been avoided. 

The problem of poor spares management is common across a lot of sites we work at. The root cause generally stems from inadequate asset management strategies and maintenance plans.  Many sites forget that spares are simply another way to manage the risk of asset failure in the same way as maintenance tactics; only they’re intended to mitigate the consequences of asset failure rather than make a failure less likely. 

Our solution for a critical spares analysis is to conduct a site wide asset criticality assessment to first identify/confirm critical systems and equipment. Then we check the maintenance strategies in place to ensure they are effective. 

We use our criticality assessment tool to determine the mitigated and unmitigated (based on the current maintenance strategy) criticality ratings for every asset. The tool imports the asset hierarchy from the ERP, and by assigning likelihood and consequence factors to each asset, allows calculation of a hazard and process criticality severity ranking. 

We then prioritise developing/reviewing asset management plans based on the criticality assessment results. 

The key elements of the asset management plans define the asset's productive life, operating context and operational limits, as well as their scheduled downtime, condition monitoring and component change-out strategies. We've previously written about the value of asset management plans 

The analysis of spares criticality can be carried out quickly and easily after the context and understanding of the asset management plans, based on criticality, is well understood. 

Sites often think that they have little control over their critical spares. The problem often is with all the spares, not just the critical ones. 

It is important for maintenance to understand that they must trigger a demand signal (requirement) on supply to deliver the part. They should not just assume that supply know what parts they want and when they want them. Maintenance planners must use the asset strategy to help supply set the right stocking strategy. Avoid relying on inventory optimisation tools to do this. 

As a result of the project, we were able to deliver to the client a full critical spares analysis and recommendations for completing or updating asset management plans for around three dozen of its most critical assets.  The project also highlighted for the client a number of gaps in their understanding of the condition of their assets, or tactics needed to manage them.  The benefits will therefore extend beyond those the client intended to achieve with the original project brief; namely fewer unplanned failures due to a more effective asset management plan. 

Our advice in relation to critical spares analysis is to understand your asset criticality first and foremost. This must be carried out over the entire reach of your operation. Then investigate the effectiveness of the asset management plans. Only then can you get control over your critical MRO spares.


By James Owen

By darren

Date :

January 31, 2019