Categories of Application Functions
When determining the importance of an application function, ask “How long can we live without this function?” One successful testing approach divides application functions into three categories, as follows:
• Functions that are business critical, and must be operational immediately after the upgrade. No delay is permitted. Examples may include customer order entry, shipping, and production order release functions.
Functions in this category must be tested thoroughly.
• Functions that are important, but the business can survive their loss for a few hours after the upgrade. Examples may include most inquiries and accounting functions, and high-visibility management reports, especially if management is made aware of the possibility of a one-time delay.
Functions in this category should be tested as time and resources permit.
• Functions that can be broken for a day or two without serious impact. Examples may include reports, analysis functions, and end-of-period routines.
Functions in this category can typically be spot checked.