When breakdown maintenance gets out of control, proactive maintenance management can take a back seat to “fighting the fires”, leading to a spiraling decline in availability. Recently, Bluefield worked with a client to improve the reliability of their underground mining equipment. With the implementation of a simple metric called Run Time After Service (RTAS), Bluefield focused the maintenance team on breakdown and defect management.
Bluefield worked closely with the client to identify maintenance defects during equipment servicing. Industry experience suggests that work completed in a planned and scheduled manner can be completed up to three times faster than work that is not planned and scheduled.
The 3:1 gain in efficiency is due to execution in a controlled environment. This means the defect will be corrected using scheduled labour, with parts in hand and within the workshop; all factors contributing to a quality repair outcome.
Regardless of the priority of a defect, each should be recorded to allow planning of the repair at a future opportunity.
Once the defects have been identified the planner can then assign a priority, balance resources and schedule the task for completion at a suitable opportunity.
Effective defect elimination practices are also essential for minimising unplanned downtime and reduce the waste associated with breakdown maintenance.
Defect elimination is successful when the maintenance strategy is adjusted to prevent recurrence of an unplanned event. Other effective defect elimination initiatives include improving inspections to enhance condition-based maintenance, operator training to reduce accident damage, and task standardisation to reduce maintainer-induced failures.
One critical component of our site project was focusing on defect management during service opportunities. Bluefield implemented a leading indicator called Run Time After Service (RTAS). Post service, RTAS measures how long the equipment ran before encountering its first breakdown. The aim was to focus the maintenance crews on reducing the defects that would lead to an in-field failure prior to the next service.
The results immediately showed an increase in the trends until it peaked after 2 months as shown below.
The decline after month two was due to workshop bays restrictions due to refurbishment, and labour shortages. This led to a reduced focus on defect management during servicing simply to “get the equipment out the door”. Once the team was re-focused on defect elimination, the RTAS metric began to climb and availability increased. Consequently, the planned-to-unplanned work ratio moved in the right direction.
Overall, the focus on defect management has yielded positive results in key performance metrics and continues to improve. As a leading indicator to availability, the focus on RTAS is helping our client move towards their targets through changes in their approach to maintenance. For Bluefield, our first focus is always on getting the basics - such as workshop execution quality – working well to build a strong foundation for sustained improvement in asset performance.