Shift wise production report prepared for performance of the machine on the basis of rough estimated or measurement.
In this method production of O.B and coal measure to complete a cycle or trip of machine or vehicle.
Rough measurement = No.of trip of vehicle × Av carrying capacity of the vehicles.
Accuracy of this method depend on.
(a) full load capacity of vehicle: If vehicle carrying less or more load effect on estimate measure quantity.
(b) If the bucket is filling material not loads from its capacity that affect the result of estimate measure quantity.
(c) if material dropped outside of dumper/tipper.
(d) Stuck the material into the bucket effect the estimate measure quantity.
(e) Counted wrong cycle / trip
(f) Swell factor of the material.
For determine accurate quantity ofexcavated material . This can be done only by survey measurements.

For accurate survey measurement, the reduced levels at 15 mt taken of the working area at the end of the month.For this purpose measurement of Original ground level taken before start the excavation.
When coal seam is exposed the reduced level also taken before excavation of coal. and level of coal floor also taken.
Calculate the volume of coal and overburden.
The monthly survey measurement figure will be compared with the cumulative daily estimate measurement figure for the corresponding period and a correction factor arrived at for reporting the daily figures the next month.
Let Q be the quantity of OBR / COAL as per survey measurement a particular period.
Let Q1 be the cumulative reported daily estimate measure figure for that particular survey measurement period.
Then correction factor = Q/Q1