PRECISION AND ACCURACY OF TIME-SLOTTING BASED UPON AN ASSUMED LOG NORMAL DISTRIBUTION OF SAMPLE WORK TASK TIMES.

In this paper, we analyze the work measurement technique known as time-slotting. Time-slotting uses a single time value to represent the time standards of all of the tasks whose standard times lie or appear to lie in a specified time range. The single time value is known as the slot-time and the specified time range as the time-slot. A series of time-slots together form a slotting scale. In our analysis, we consider the applicator error, which result from the applicator, or estimator, allocating a task, whose time is being estimated, to the wrong time slot. We assume that the work task times are distributed Log Normally and derive expressions of the applicator errors. The complexity of the resulting equations require the use of computer programs, which are written for a microcomputer. We also present numerical results obtained using these equations. The results can be used for designing and evaluating time-slotting scales.