2-Sample t for Decrease Total Supply Chain Management Cost As A Proportion Of Sales

Use 2-Sample t to demonstrate that average total supply chain management cost as a proportion of sales decreases after a process improvement.

This example applies to the Supply Chain Module. For more information, go to www.minitab.com/supply-chain-module.

Example

Total supply chain management cost as a proportion of sales is the total supply chain costs for a specific time period divided by the total sales.

In this worksheet, Total Cost Proportion contains the total supply chain cost as a proportion of sales. Process Change indicates whether the cost is before or after a process improvement.

C1	C2-T
`Total Cost Proportion`	`Process Change`
0.164	Before
0.163	Before
0.171	Before
0.149	After
0.156	After
0.144	After

How-to

Choose Solutions Modules > Functions > Supply Chain KPIs, then select Launch.
Under Costs, select Cost as a proportion of sales.
Select Decrease total supply chain management cost as a proportion of sales, 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 that contains the total supply chain cost as a proportion of sales.
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 total supply chain cost as a proportion of sales has decreased after the process change.
Click OK.

Tip

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