Work Performance and Methods

Industrial engineers are expected to know the basic definitions and concepts of work measurement without needing to consult reference materials.

A task is a sequence of elements. Each task or element must have a definite end event that is also the start event for the next task or element. All time that is not part of a task or element is allowance time time allowed for personal activity (breaks, phone calls), fatigue, and delays.

Time study yields observed times; let the ith replication of the observed time (observed duration) of task or element j be denoted O _ij. The observed time is measured by videotape or stopwatch as the time from the start event to the end event (after subtraction of the duration of any allowance-time interruptions).

Each observed time O _ij is converted to a normal-time datum N _ij by multiplying by the pace rating, R _ij, which is a subjective estimate of the pace of the work. Normal pace ( R _ij = 1.00) is defined as the speed at which a typical experienced worker would be expected to work; R _ij = 0.85 would express that the worker was working at a pace such that the number of completions per unit time would be 85% of those at...