Question

An initial time study was done on a process with the following results​ (in minutes). Based on the data obtained so​ far, assuming an allowance of 13 percent of the normal​ time, what do you estimate for the time per customer​ served, based on this preliminary​ sample? ​(Round all intermediate calculations to two decimal​ places.)                     Element   Performance Rating   Obs 1   Obs 2   Obs 3   Obs 4   Obs 5
Element 1 80 6 6 3 5 3
Element 2 120 9 10 9 10 11
Element 3 90 7 8 6 8 6

Answer 1

We tabulate the data as shown below and find the mean for each element:

We know, normal time for an element = Mean * Performance rating

Standard time for element = Normal time * (1 + Allowance) = Normal time * (1 + 13%) = Normal time * (1 + 0.13)

Based on above formulas, we find normal time and standard time for each element and find total standard time of the process

The total standard time for the process is shown highlighted in green

The above table in form of formulas is shown below for better understanding and reference:

Hence, estimate for the time per customer​ served, based on this preliminary​ sample = 24.57 minutes