22 The work element times for a repetitive work cycle are listed in the table below, as deter- mined in a direct time study using the snapback timing method. Elements a and b are operator-controlled. Element c is a machine-controlled element and its time is constant. Element d is a worker-controlled irregular element performed every 10 cycles. Elements a and b were performance rated at 90%, and element d was performance rated at 75%. The worker is idle during element c, and the machine is idle during elements a, b, and d. One product unit is produced each cycle. No special allowance is added to the machine cycle time (element c), but a 15% allowance factor is applied to the total cycle time. (a) Determine the standard time for this cycle. If the worker produced 190 units on an 8-hour shift dur- ing which 7 hours are actually worked, (b) what was the worker's efficiency, and (c) what was his performance during the operator-paced portion of the cycle? b d Work clement Observed time (min) 0.75 0.30 1.62 1.05