Chapter 15: Gap Detection

Chapter 15: Gap Detection Transcript

Another commonly performed test is to check for gaps in sequences of numbers. Series such as purchase orders, invoice numbers, cheque numbers and this sort of thing are typically sequential and any gaps should be accounted for. To test for gaps, we’ll run a task called Gap Detection.

Start by opening the Sales Transaction database. On the Analysis tab, in the Explore group, click Gap Detection. Gap detection can be run against character strings, number sequences and dates to search for missing information. In the field to use drop-down, select Invoice number. This is a character string so we’re verifying against the mask indicated in the model. Ensure the Create Result is selected and provide a name for the result such as Missing Invoice Numbers. Click OK to start the process.

The end result set indicates that there are two missing invoices, one ending in 98 and ending in 351. As an analyst, you’ll want to investigate this and find out what happened to these two invoices.