A worker-machine operation was found to involve 3.5 minutes of machine time per cycle in the course of 40 cycles of stopwatch study. The worker's time averaged 2.8 minutes per cycle, and the worker was given a rating of 120 percent (machine rating is 100 percent). Midway through the study, the worker took a 10-minute rest break. Assuming an allowance factor of 15 percent of work time which is applied only to the worker's element (not the machine element), determine the standard time for this job.

The answer is

To compute for the standard time of the job, the following steps must be undertaken;

Step 1: Compute the normal time for both the machine and the worker.

Step 2: Compute the standard time for both the machine and the worker.

Step 3: Calculate the standard time of the job.

Accordingly, we will be doing at least three steps to determine the standard time of the job.

But before anything else, let us laid down first the important details as follows;

• Observed Time for the Machine = 3.5 minutes
• Machine's Performance Rating = 100%
• Observed Time for the Worker = 2.8 minutes
• Worker's Performance Rating = 120%
• Allowance Time = 15%

Step 1: Compute the normal time for both the machine and the worker.

Normal Time = Observed Time x Performance Rating

Normal Time (Machine) = 3.5 minutes x 100%

Normal Time (Machine) = 3.5 minutes

Normal Time (Worker) = 2.8 minutes x 120%

Normal Time (Worker) = 3.36 minutes

Step 2: Compute the standard time for both the machine and the worker.

Standard Time = Normal Time x Allowance Factor

Standard Time (Machine) = 3.5 minutes (Standard time for the machine will remain 3.5 minutes since there is no allowance factor for the machine.)

Standard Time (Worker) = 3.36 minutes x ( 1 + 0.15)

Standard Time (Worker) = 3.864 minutes

Step 3: Calculate the standard time of the job.

Standard Time of the Job = Standard Time (Machine) + Standard Time (Worker)

Standard Time of the Job = 3.5 minutes + 3.864 minutes

Standard Time of the Job = 7.364 minutes