Software Non-functional Assessment Process (SNAP)
The Software Non-functional Assessment Process (SNAP) sizing process is very similar to the function point sizing process. Within the application boundary, non-functional requirements are associated with relevant categories and sub-categories. Using a standardized set of basic criteria, each of the sub-categories is then sized according to its type and complexity; the size of such a requirement is the sum of the sizes of its sub-categories. These sizes are then totaled to give the measure of the non-functional size of the software application. The SNAP model consists of four categories and fourteen sub-categories to measure the non-functional requirements. Non-functional requirements are mapped to the relevant sub-categories. Each sub-category is sized, and the size of a requirement is the sum of the sizes of its sub-categories. While function points to measure the functional requirements by sizing the data flow through a software application, SNAP measures the non-functional requirements. It is therefore complementary to FPA.