Question

The manager of the Dinners Delight franchised restaurant chain is in the process of establish quality-control charts for the time that its service people give to each customer. Management thinks the length of time that each customer is given should remain within certain limits to enhance service quality. A sample of 3 service people was selected, and the customer service they provided was observed four times. The activities that the service people were performing were identified, and the time to service one customer was recorded as noted below:

Service Person Sample 1 Sample 2 Sample 3 Sample 4
1 200 150 175 90
2 120 85 105 75
3 83 93 130 150
4 68 150 145 175
5 110 90 75 105
6 115 65 115 125

A sample of six service personnel was observed, and the following customer service times in seconds were recorded: 180, 125, 110, 98, 156, and 190. Is corrective action called for?

Answer 1

The behavior is regulated as well as corrective measures are not necessary. A further explanation is provided below.

Step-by-step explanation:

According to the given,

Mean,

= 143.17

Standard Deviation

= 37.91

Sigma level,

= 3

Now,

The upper control limit will be:

⇒ UCL =
`Mean+3SD`

On putting the values, we get

=
`143.17 + (3* 37.91)`

=
`143.17 + (113.73)`

=
`256.9`

The lower control limit will be:

⇒ LCL =
`Mean-3SD`

On putting the values, we get

=
`143.17 - (3* 37.91)`

=
`143.17-113.73`

=
`29.44`

Even though all values are somewhere between LCL as well as UCL. Thus the above is the right answer.