Call Centres

Scenario 1

A call centre providing services under contract to a number of firms in the leisure industries has been in operation for around a year. Expected levels of productivity and customer satisfaction have not been attained, and the management group are looking for ways of understanding what improvements need to be introduced. They have attempted to use SPC on call duration, based on the principle that calls should be of a standard duration. This standard duration supposedly (on the one hand) maximises the number of calls a given operative can handle and (on the other hand) maximises the possibility that the members of public on the other end of the line will receive the service they require. A short experiment led the managers to believe that this optimal standard duration should be 210 seconds. Over a period of 2 weeks they then monitored the actual call durations. Each day, they sampled 12 calls, and measured the mean and range of durations in the sample. These are tabulated, in seconds, in the following table.

Question 1

The upper and lower control limits for the means on a means-range (X’-R) chart that uses this data are:

A: 225, 200

B: 230, 200

C: 200, 100

D: 80, 13

E: None of the above

Question 2

The upper and lower control limits for the ranges on a means-range (X’-R) chart that uses this data are:

A: 225, 200

B: 230, 200

C: 200, 100

D: 80, 13

E: None of the above

Question 3

The data point that can most sensibly be excluded from analysis is:

A: Week 2 Day 3

B: Week 1 Day 3

C: Week 1 Day 4

D: Week 1 Day 1

E: None of the above

Question 4

A reasonable inference from the means data alone is:

A: The process is clearly in control

B: The process is clearly out of control

C: It is unclear whether the process is in control

D: The process is sometimes in control, sometimes not

E: None of the above

Question 5

A reasonable inference from the ranges data alone is:

A: The process is clearly in control

B:...