Functional analysis is necessary for a user to understand in detail how a system works or should behave. Functional analysis is a continuation of Use Case scenario refinements, using diagrams describing the behavior of a system, e.g.,  SysML Activity, SysML Sequences, or SysML State Machine diagrams. A new SysML Activity diagram should be created for every function of a Use Case allocated to a particular block or part. Although there are two or even more Swimlane partitions, you should choose only those functions that are nested under the partition representing the Block which captures your system

The following chapters describe each feature's functionality.