Part 9. Draining the Swamp

This is the 9th article in my series inspired by “Simplifying Mining Maintenance” by Gerard Wood.

In this article, I look at the last important part of the puzzle for effective maintenance outcomes - Scoping and Planning .

As Gerard noted in his book

“People in a reactive mining maintenance environment are busy. They deal with the same problems over and over. They never have time to plan because they run from one emergency breakdown to the next."

Fundamentally, it all boils down to the concept of “reactive” vs “proactive” maintenance. Constantly fighting fires and having a “hero” maintenance culture for fixing breakdowns are unfortunately all too common in the mining industry. What’s more, this environment can be highly stressful, with maintenance managers getting calls at all hours of the day with new problems and breakdowns that need fixing. What makes it worse is that this can lead to disillusionment and burnout for maintenance managers that actually want to do better and improve maintenance culture and performance. The all too common reality is that there is just no available time or resources to make it happen. They are too busy wrestling alligators to drain the swamp.

However, as I have written in the previous articles, by getting the fundamental elements in place to be able to “do the right things, right”, the amount of breakdowns should decrease. But doing the right things at the right time is also essential.

”Planning and scheduling only helps once the basics are in place. If these fundamentals are not developed first, planned and scheduled work will always be interrupted by breakdowns.”

There is actually quite a lot to unpack regarding planning and scoping. The foundation is in the development of the maintenance plan and being able to optimise it to increase reliability without excessively reducing availability. This can be difficult to balance, and is a topic that Gerard and his team at Bluefield have written a number of articles about.

The next important step is to have appropriate TARPs in place for condition management based on in-service inspections. TARP’s are essential for risk management and formalising and standardising responses to defects. Everyone is familiar with using these for oil analysis, but they are often poorly applied (if at all) for in-service cracking. In my experience, sites all too often rely on the highly subjective and arbitrary condition assessment rating of the NDT technician carrying out the inspection. The result of this is that there is no consistency in risk management -it all depends on the experience of the technician and/or how risk averse they are. Mines often have some form of TARP for cracking, but the problem is that there are usually no set size thresholds for cracking to provide a basis for condition severity.

There is much more to this topic that I written about in other articles and posts (we have solved this issue in a simple way through the development of the Crack Data System), but for now the key thing to consider is how to accurately and consistently set crack size thresholds to be able to drive repair planning and repair priority for cracking on service days. As I mentioned previously, the TARP concept is basically a risk management strategy. The reality is that the appropriate maintenance strategy needs to be considered on a case by case basis. Not all cracks need to be repaired straight away - they may not be actively growing (the crack length must be trended to know this though) or there may be higher risk areas that need to be repaired first with the available resources. Monitoring is also a useful strategy so that the crack can be repaired at a convenient time, or the scheduled maintenance can be brought forward if the risk increases.

“Often you find a defect - such as a small crack that seems to be getting worse - that doesn’t need to be fixed right away. The machine can continue operating, but you must keep an eye on these defects and manage the problem until the next scheduled service. When that comes, you can address it with adequate time and care. If the problem worsens, you can move up the date of the next scheduled maintenance.”

With the plan and strategy in place, the next part is planning execution. It is essential to have the right scope. Maintenance planning essentially boils down to Time, Resources and Logistics, but often with constraints from Production on the down-time available.

In regards to crack repairs, the following aspects need to be considered

Time

The required repairs must be able to be completed within the planned downtime. This means that the planner needs to have a good understanding of

• Which cracks need to be repaired and on what priority level
• How long the required crack repairs are estimated to take
• Balancing the planned workload with the available labour. For example, 12hrs of crack repairs can’t be completed by one welder in an 8hr shift.

Resources

For crack repairs, there are a number of things that fall under the general banner of “resources”, but these can be generalised as labour, materials, support, and welding equipment.

Welding Labour

• How many welders are required for the planned repairs to be able to complete them within the available time?
• What competency levels do the welders need to be for the planned repairs?
• Are TA’s needed?
• Is a welding supervisor or specialist required?
• Are NDT technicians required to carry out QA and final inspections?

Parts, tooling and materials

• Are any replacement parts or specialised tooling required to be able to access the area to be repaired?
• Is replacement material required? (eg a section of plate of specific grade and thickness)

Support

• Fitters - will any fitters be required to dismantle components to provide access to the area to be repaired
• Spotters - are fire spotters required?
• Is specialised access equipment needed? (heights, confined spaces etc)
• Cleaning - does the area need to be cleaned prior to the repair? Thorough removal of grease is essential for an effective repair.
• Technical - is a specific repair procedure required?

Welding Equipment

• Welding equipment and support tools - do the welders have the necessary welding equipment for the planned repair? Is specialised equipment needed?
• Are the right welding consumables available for use - type, strength grade, etc
• Preheat equipment - is the necessary equipment available or is specialised preheat equipment necessary (such as heat beads or induction).
• Do the welders have all the necessary PPE and related consumables
• Is Post Weld Heat Treatment required?

Logistics

Consideration needs to be given to how all of the planned activities will be carried out

• Does the asset need to be set-up in a particular way to provide ease of access or to enable the repair?
• Interactions - will there be adverse interactions between different planned work fronts. For example, are repairs planned in the engine bay while the engine is being opened up? Will welding activities potentially prevent other planned maintenance or vice versa?

Planning doesn’t end here though. It is important to properly close-out and follow up too.

“When work is completed, there must be a disciplined close-out to ensure people know what is going on in their business”

This means checking to see whether the planned work was completed or not, what is still outstanding, and identifying any issues that may have come up that could have been avoided by better prior planning. If a high priority crack repair was not done, it is important to both understand the reason(s) why in order to improve future planning, and it is also necessary to carry out suitable risk management. There are a number of potential options when it comes to risk management of cracking, and this ties back into the TARP. Potential risk management options for cracking include (from least to worst severity/risk cracks)

• Do nothing and leave until next planned maintenance
• Implement additional monitoring
• Carry out a temporary repair (eg crack arrest hole)
• Out-of-schedule maintenance to complete the repair

When reviewing the completed work, it is also important to be aware of any temporary or partial repairs that were completed. As noted in Simplifying Mine Maintenance

“Temporary repairs must be done at times and are okay as long as you raise a subsequent action in the CMMS to ensure a permanent repair is made. Temporary repairs that are not raised and corrected permanently lead to future breakdowns”

This is why it is important to have a suitable QA process for crack repairs that identifies the repair status so that suitable follow-up plans can be made. In the AICARM framework, the Crack Repair Sheet clearly shows the status of each crack on completion of planned work

• Fully repaired
• Temporary or Partial
• Repaired using Backing Material
• Not Repaired

As you may note in the above list, knowing whether a full thickness single sided repair was made using backing material is also important. This is because repairs made using backing material typically tend to crack from the root of the repair. This means that large cracks will suddenly appear at the surface, which may cause urgent repairs or additional unplanned work during maintenance days if the cracking is detected then. Furthermore, the presence of the backing material can make subsequent repairs very difficult to do properly. Typically the only solution is to plan entry into the space (if possible) to remove the backing material and back-gouge any cracks/defects. Similarly, suitable risk management and future planning is required for Temporary and Partial repairs.

Unfortunately, all too often in my experience, planning for crack repairs typically is just assigning a fixed amount of labour and then leaving it up to the Supervisor or even the welders to decide what to repair. There is no proper planning or strategy. This is not necessarily due to bad attitudes and practices. It is just all too hard when there is inadequate NDT data and no good ways for properly and effectively managing crack repairs on a mine site. Simple crack length information alone is insufficient and inadequate both for planning and risk management. Without suitable NDT data, it is impossible to formalise strategies for repair planning and establish condition severity thresholds. It is impossible to determine the required welder competency level for the nature of the repair. It is impossible to accurately estimate the time required to complete the repair if crack depth and material thickness are not known.

Stop wrestling alligators. WQMS? provides you with the tools to “drain the swamp” and reduce the amount of structural cracking by using the AICARM Framework, along with the Maintenance Welder Competency microcredential and Crack Data System nomenclature.?