Question

The following data resulted from a time study taken on a horizontal milling machine: (NOTE: For machine operations, rating factor is 100%) Mean manual effort time per cycle: 4.62 minutes Mean cutting time (power feed): 3.74 minutes Mean performance rating: 115% Machine allowance (power feed): 10 percent Fatigue allowance: 15 percent What is the standard time for the operation? Required: What is the standard time for the operation? This should be the summation of both machine and manual operations NOTE: This should be the summation of both machine and manual operations For computing the normal time, machine operations should be separated first from manual operations since rating factor for machine operations is 100%.

Answer 1

The standard time for the operation is 7.425 minutes, which is the sum of the standard times for both machine and manual operations.

Step-by-step explanation:

To find the standard time for the operation, we need to separate the machine operations from the manual operations. The rating factor for machine operations is 100%, so the machine allowance is already included in the mean cutting time. The standard time for machine operations is 3.74 minutes. To calculate the standard time for manual operations, we need to subtract the machine allowance and fatigue allowance from the mean manual effort time. The machine allowance is 10% of the mean cutting time (10% of 3.74 minutes = 0.374 minutes) and the fatigue allowance is 15% of the mean cutting time (15% of 3.74 minutes = 0.561 minutes). Therefore, the standard time for manual operations is 4.62 minutes - 0.374 minutes - 0.561 minutes = 3.685 minutes.

Now, we can calculate the total standard time by summing the standard times for both machine and manual operations. The total standard time is 3.74 minutes (machine operation) + 3.685 minutes (manual operation) = 7.425 minutes.