2-Sample t for Decrease Cost Per Ticket

Use 2-Sample t to demonstrate that average cost per ticket decreases after a process improvement.

This example applies to the Customer Contact Center Module. For more information, go to www.minitab.com/customer-contact-center-module.

Example

Cost per ticket is the total operating expenses of the contact center divided by the number of tickets over the same time period.

In this worksheet, Cost Per Ticket contains the cost per ticket data. Process Change indicates whether the cost per ticket is before or after a process improvement.

C1	C2-T
`Cost Per Ticket`	`Process Change`
$17.09	Before
$22.45	Before
$19.45	Before
$21.37	Before
$17.44	After
$16.03	After

How-to

Choose Solutions Modules > Functions > Customer Contact Center KPIs, then select Launch.
Under Utilization and Cost, select Cost per ticket.
Select Decrease cost per ticket, then click OK.
Select 2-Sample t, then click OK.
From the drop-down list, select Both samples are in one column.
In Samples, enter the column of cost per ticket data.
In Sample IDs, enter the column that indicates whether the data are from before or after your process improvement.
Click Options. In Alternative hypothesis, select Difference > hypothesized difference. The hypothesized difference defines your null hypothesis. By default, the hypothesized difference = 0. This one-sided test has greater power to detect whether the cost per ticket has decreased after the process change.
Click OK.

Tip

For more information about this analysis, click Help in the main dialog box.