After looking at a solution, you may want to vary the requirements. For example, you may have had in the requirements functionality, the ability to scan orders that were faxed to you and store them in a separate database. The software may input faxed orders directly into the system using a standard layout for the order fax and send a confirming fax with stock availability and estimated delivery date. The requirements may need to change.
Those changes may also mean you need to check other functions
that you have not covered such as the confirming fax above.
If so, schedule another demonstration of the functionality
with the Vendor. Obviously if you had a number of these revisits,
you would schedule them all into one session.