During a particular 40-hour week of an automated production operation, 381 acceptable (nondefective) parts and 17 defective parts were produced. The operation cycle consists of a processing time of 5.23 min, and a part handling time of 0.58 min. Every 50 parts, a tool change is performed, and this takes 4.2 min. The machine experienced several breakdowns during the week.
Determine
(a) hourly production rate of acceptable parts,
(b) scrap rate, and
(c) availability (proportion uptime) of the machine during this week.

Part A:

Hourly production rate of acceptable parts=9.525 parts/hr

Part B:

Scrap rate=0.042713=4.2713%

Part C:

Proportion uptime=0.9774215=97.74215%

Explanation:

Part A:

Acceptable (non-defective) parts=381

Hours Per week=40

Hourly production rate of acceptable parts=Acceptable (non-defective) parts/Hours Per week

Hourly production rate of acceptable parts=

Hourly production rate of acceptable parts=9.525 parts/hr

Part B:

Total Parts Produced=Non-defective parts-Defective parts

Total Parts Produced=381+17

Total Parts Produced=398

Scrap rate=17/398

Scrap rate=0.042713=4.2713%

Part C:

Total Time for operation=5.23+0.58+()

Total Time for operation=5.894 min

Total up time=398(5.894)=2345.812 min=39.09686 hr

Proportion uptime=

Proportion uptime=0.9774215=97.74215%

unlike the threaded fasteners which are used to clamp the machine members, power screws are used to transmit power. common applications of power screws are: screw jacks: to lift weight. lead screw of lathe: for axial movement of tool and its precise positioning.