Question

In a 4 machine production line Machines 1, 2,3 and 4 have scrap rates: 1.5%, 4%, 2%,

and 3.8% respectively. What is the overall acceptable quality percentage for the line?

Answer 1

Let input quantity = 100.N

Since scrap rate in machine 1 is 1.5% . output from machine 1 is 98.5% of 100.N = 98.5N

Input to machine 2 = 98.5.N

Since scrap rate in machine 2 is 4% , output from machine 2 is 96% of 98.5.N = 94.56.N

Input to machine 3 = 94.56.N

Since scrap rate in machine 3 is 2% , output from machine 3 is 98% of 94.56.N = 92.67N

Input to machine 4 = 92.67N

Since scrap rate in machine 4 is 3.8% , output from machine 4 is 96.2% of 92.67.N = 89.14.N

Thus , while input to the line = 100.N , output from the line = 89.14.N

Therefore , acceptable quality percentage from the line = 89.14/100.N x 100 = 89.14%

OVERALL ACCEPTABLE QUALITY PERCENTAGE FOR THE LINE = 89.145