For example: — In measuring the output of a concrete gang, counting cement bags provides an incentive to use more cement than the instruction card calls for. Counting the batches of concrete dumped out of the mixer, provides an incentive to use rather smaller quantities of broken stone and sand than the proportions call for, — and, furthermore, does not put the incentive on the men to spill no concrete in transportation, neither does it put an incentive to use more lumps for Cyclopean concrete.
Measuring the quantity actually placed in the forms puts no incentive to watch bulging forms closely.
While measuring outputs by all these different units of measurements would be valuable to check up accuracy of proportions, accuracy of stores account, and output records, the most important unit of measurement for selection would be, "cubic feet of forms filled," the general dimensions to be taken from the latest revised engineer's drawings.
Necessity for Checking Errors. — Dr. Stratton says, — "No measurements, whether they be psychic or physical, are exact beyond a certain point, and the art of using them consists largely in checks and counter checks, and in knowing how far the measurement
is reliable and where the doubtful zone begins." [18]
Capt. Metcalfe says, — "Errors of observation may be divided into two general classes; the instrumental and those due to the personal bias of the observer; the former referring to the standard itself, and the latter to the application of the standard and the record of the measurement." [19]
The concrete illustration given above is an example of careful checking up. Under Scientific Management so many, and such careful records are kept that detecting errors becomes part of the daily routine.
SUMMARY
Results of Measurement to the Work. — Under Traditional Management, even the crudest measurement of output and cost usually resulted in an increase in output. But there was no accuracy of measurement of individual efficiency, nor was there provision made to conserve results and make them permanently useful.
Under Transitory Management and measurement of individual output, output increased and rewards for the higher output kept up the standard.