Productivity
Delay Pareto: find the few causes behind most lost time
Most pits lose more time to waiting than to slow digging. The trouble is that waiting is rarely written down. A delay Pareto fixes that: rank the causes by lost time, and the first two or three bars show where to act.
Log every delay with a reason and a duration
A delay without a reason is just a gap. Use a short, fixed list so entries are consistent: wait for truck, dozer on the floor, grader, water truck, lighting plant, reposition, hard dig, blast hold. Record a start and stop, not a guess at the end of shift.
Group reasons into categories
Fifty reason names make a chart nobody can read. Give every reason a category such as truck supply, auxiliary equipment, face conditions, safety or planned. Group by category first, then drill into the biggest one.
Build the Pareto
- Add up the time lost per reason or category.
- Sort from largest to smallest.
- Draw bars in that order and a cumulative percentage line on top.
- Circle the bars that carry the first 70 to 80 percent of the time.
Those bars are your work list. Fixing the fifth bar will never move the production number.
Separate controllable from uncontrollable
A blast hold may be outside the shift's control; a dozer arriving late is not. Tag delays as planned, unplanned or external so you can report what supervision can really change.
Close the loop
Repeat the study after the fix. If wait-for-truck fell but the match factor rose above 1.0, you moved the problem from the loader to the queue. Measure again before celebrating.
Time your own cycles. CycleStudy Pro records loader and truck cycles offline and does this maths for you. Get the Android app or try the free calculators.