Understanding the critical maintenance backlog

December 9, 2015 12:44 pm
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This is the third in my series of articles around developing effective maintenance capability. In my first, I discussed a simple model for developing capability, and in my second I discussed the key roles and capability required in the maintenance organisation.

In this article I’ll explore how you can understand the scale of your maintenance back log, and how to quantify the impact this has your ability to offer the Asset Owner the capability they require from those assets. By understanding cost and risk you can then effectively engage in meaningful discussions around release of funds to restore or replace degraded assets.

What is the critical maintenance back log?

The aim of maintenance is to ensure that fixed assets deliver the functional capability required by the Asset Owner, preferably at the level they delivered when they were first installed or procured. If the functional capability has degraded below this level, then we are faced with a maintenance backlog. This can be explained through a simple example: if we procured a pump to deliver 10 m3 of flow per hour at 5 bar, but it can now only achieve a flow of 8 m3 per hour at 4 bar, then we have a maintenance back log. This back log becomes critical when it impacts on the overall output of the production facility. If the pump above feeds a header tank which in turn feeds a process requiring 7 m3 per hour, then the back log is not critical. If it feeds a fire suppression system rated at 9.5 m3 / hour at a pressure of 4.5 bar – it is critical.

To address the maintenance back log, we need to restore the asset to its basic conditions. Attempting to apply CI tools before this has been done is worthless, technical restoration is required first.

Identifying the critical back log

When taking over as Site Engineering Manager on a legacy site, the scale of the maintenance back log can be daunting. In addition, it’s often difficult to get a consistent view of which elements of degradation are critical versus nice to have. You need clear guide lines and a manageable process to “eat the elephant in small bites”. A typical approach would be:

  • Form a team to analyse the assets – many heads are better than one for this form of complex analysis. Build a multi-dimensional team. As well as maintenance input, look to get operational, quality and financial input into the analysis. This will ensure a better analysis and better stakeholder engagement when you start to request funds.
  • Consolidate a “good enough” asset register – many legacy sites have, at best, an incomplete asset register. A reasonably, though not perfectly, asset register is required to see the size of the problem. All the way through this process focus should be on “good enough”, after all we’re maintenance engineers who work in an imperfect world. Collate the information at major asset level: you can drop down to assembly and sub-assembly level at a later pass through the analysis
  • Complete a criticality analysis on the asset base – there are many tools and flow charts available on the internet to guide this. You are looking for a simple process that allows you to apply professional judgement to build a quantitative assessment of asset criticality using agreed criteria. A typical criticality analysis will score assets on safety, environment, quality, working time, break down frequency and break down consequences to give a high, medium and low criticality rating. From this point on, you focus on high criticality assets only.
  • Detailed analysis of the critical assets – at this point you are starting to analyse all the available data you have for the assets to understand what it should do, and what it can do. The team should consider:
    • Operating context – what does the asset owner want from it?
    • OEM surveys
    • Breakdown records
    • Root cause failure analysis involving the asset
    • Known improvement plans
    • Operator & maintainer knowledge
    • Any other relevant data
  • Review the outputs and generate a risk profile – once the original and current operating context are understood, then the current gap can be quantified. This will never be an exact science, but an indicative risk profile can now start to be assigned to the asset in terms of the impact of the depredation. The more this can be translated to business language (impact on the profit and loss) the easier subsequent requests for funding become
  • Develop a restoration strategy – a number of choices are available here ranging from replacement through full restoration to partial regeneration or acceptance of the degraded capability. Whichever solution is recommended, it needs to relate to the risk profile identified above
  • Activate and execute the restoration strategy – start tackling the critical restoration with your existing maintenance budget. Don’t wait till you have all the available data. If you can demonstrate value to the stakeholders in your existing budget, you’ll find it a lot easier to secure additional funds.


Too many engineers coach requests for funds for restoration in black and white terms; “I need additional funds for maintenance or the asset will fail”. The reality is few assets fail catastrophically, they degrade. As the impact of the degradation is not understood or communicated, the request for additional funds is often refused. When the asset doesn’t fail, the view that maintenance wants more money for no reason is reinforced and inevitably leads to a mind-set in the business that maintenance can be deferred or ignored indefinitely. By turning restoration into a risk-based discussion, there is a much greater likelihood of securing funds for replacement or regeneration.

For additional information on the Coriolis Maintenance Capability Programme, and how to apply it in your business, please contact us.

Written by Richard Jeffers, Coriolis Limited