As standard time = Set up time + Time per piece * No. of pieces produced . Standard time for manufacturing 50 jobs 35 + 8 x 50 435 min = 7 hours and 15 min Standard time x 100 Efficiency of operator Actual time 435 x 100 390 111.5%. ILLUSTRATION 3: Following datas were obtained by a work study. Man from a study conducted by hours. (1) Maintenance time (a) Get out and put away tools 12.0 min/day (b) Cleaning of machine = 5.0 min day (c) Oiting of machine = 5.0 min/day (d) Replenish coolant supply = 3.0 min day (i) Interruption (a) Interruption by foreman = 5.0 min/day (b) Interruption by porter etc. = 4.0 min day k14 (iii) Delay time due to power failure etc. = 6.0 min/day (iv) Personal time = 20.0 min/day Calculate total allowances, total available cycle time productive hours, considering a working day of 8 hours