2 Proportions for Improve Perfect Order Delivery Rate

Use 2 Proportions to demonstrate that the proportion of perfect order deliveries increases after a process improvement.

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

Example

Perfect order delivery rate is the proportion of orders that are error-free from beginning to end.

In this worksheet, Error-free Before and Error-free After represent the number of orders without errors before and after a process improvement. Total Orders Before and Total Orders After represent the total number of shipped orders before and after the process improvement.

With summarized data, you enter the data values instead of the column identifiers.

`Error-free Before`	`Total Orders Before`	`Error-free After`	`Total Orders After`
1253	1987	1709	1800

How-to

Choose Solutions Modules > Functions > Supply Chain KPIs, then select Launch.
Under Quality, select Perfect order delivery rate.
Select Improve perfect order delivery rate, then click OK.
Select 2 Proportions, then click OK.
From the drop-down list, select Summarized data.
In Number of events, enter the number of orders without errors before the process improvement as Sample 1. Enter the number of orders without errors after the process improvement as Sample 2.
In Number of trials, enter the total number of orders before the process improvement as Sample 1. Enter the total number of orders after the process improvement as Sample 2.
Select 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 proportion of error-free deliveries increased after the process change.
Click OK.

Tip

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