Overview
A mining company engaged Butler Advisory to improve the cycle time for planned maintenance work on their fleet of ore hauling trucks. The company was struggling with high maintenance costs and low fleet availability, costing the company $100,000 per day in lost revenue.
Methods
Data Collection:
We flew to the remote site, created a project team, and launched a DMAIC project. We discovered that the planned maintenance jobs were taking an average of 12 hours vs. a target of 6 hours. In the measure phase, the team generated a wide variety of input metrics to gather for assessment against job length. We conducted time and motion studies with the maintenance staff.
Analysis:
Our analysis revealed that, happily, the occurrence rate of issues that required further maintenance was within tolerance and not heavily impacting downtime. A lean analysis of the time and motion study data, however, revealed that 60% of PM time was non-value adding, while 31% was value-enabling and just 9% of time was spent on value-adding maintenance activities. The majority of this non-value-adding time was due to transport, motion and waiting. The average maintenance engineer was traveling 2.2km by foot per shift, despite the work occurring in just 3 areas which were 10m apart.
Lean Solutions:
We created a suite of simple, elegant solutions to dramatically reduce the amount of non-value-adding time. We created a proper 5S shop layout to reduce the distance between locations of work and the necessary tools for those jobs. Job kits were created to ensure that no maintenance work was started without ensuring all required parts were on hand and staged at the place of work. An inventory pull system was created with the warehouse & procurement teams to ensure that required parts were available just in time. Proper tool control procedures were implemented at the maintenance bay to the time waiting for tools.
Outcomes
- 50% reduction in planned maintenance time
- 9% increase in availability, which translated to a daily $90,000 increase in revenue
