OneThe operation
Limestone mines supplying a cement producer.
A heavy earth-moving fleet on fixed routes between faces and crushers, run on two shifts.
One month of records: 3,680 trips and 3,38,400 tonnes moved.
The problem
Cycle times and output were reviewed as monthly averages, which hid where time was lost, on which shift and by which trucks.
How the work is phased
AnalyseEvery trip split into queue, load, haul, dump and return.
RankLosses ranked by the time and tonnes they cost.
ExtendFleet and fuel measurement for 200 machines across the company’s mines.
In detail
- Second shift
- Output shortfall traced to smaller trucks parked for the shift
- Idle time
- Idle recorded as empty haul, separated out
- Large trucks
- Running below their benchmark cycle
- Cycle outliers
- A long tail of slow cycles, isolated by route
- Untagged material
- Trips without a material tag, a royalty exposure
- Operators
- Cycle-time spread across operators on the same route
What changes on site
Today: Cycle time as a monthly average
Cycle split into queue, load, haul and dump
Today: Idle recorded as haul
Idle separated from empty haul
Today: Shift output compared in totals
Shortfall traced to fleet parked on one shift
Today: Untagged material
Material tagged per trip