Future production requirements in the turret lathe departmen

Future production requirements in the turret lathe department must be satisfied through the acquisition of several new machines and the hiring of new operators, the exact number to be determined. There are three new parts that will be produced. Part A has annual quantities of 20,000 units; part B, 32,000 units; and part C, 47,000 units. Corresponding standard times for these parts are 7.3 min, 4.9 min, and 8.4 min, respectively. The department will operate one 8-hour shift for 250 days/yr. The machines are expected to be 98% reliable, and the anticipated scrap rate is 4%. Worker efficiency is expected to be 100%. How many new turret lathes and operators are required to meet these production requirements?

Solution

WL = (20000 * 7.3 + 32000 * 4.9 + 47000 * 8.4)/(1 – 0.04)
WL = (146000 + 156800 + 394800)/0.96 = 726667 min = 12111 hour
AT = 8(250)(0.98) = 1960 hour/year
n = w = 12111/1960 = 6.16
which is approx 7 workers and 7 lathes