The Requirements Analysis method is a 10 minute method. Using the open-source 'SysML Helper' profile takes only 10 minutes to use Rhapsody end-to-end to create a SysML project from scratch and get the requirements created in it into Rational DOORS (it takes about 1 hour to show someone how to do it).
The essential steps are:
- Create the Rhapsody project, populate a package structure with a use case diagram and setup the Rhapsody Gateway project to sync requirements into a formal module in DOORS.
- Create use cases and their related high-level requirements (goals).
- For each use case create a simplified (text-based) activity diagram of the steps including both the sunny and rainy day scenarios.
- For each step create a new, or trace an existing, functional requirement, such that all steps are covered by at least 1 functional requirement (in some cases a step may be covered by more than one requirement, or a requirement may be related to more than one step).
- (Optional) Sync all requirements into Requirements Management tool such that they can be management and tracked with allocated unique ID's.
- (Optional) Sync all diagrams into the RM tool such that they can provide additional information to support the requirements.
If we changed the system context to the glucose meter then a valid use case would be to "Take a bG reading" and a step in that use case would be to prick the finger to get blood. Note how the granularity of steps is very different when we consider the context of a system to be only the use cases that are realized by a combination of components (sub-systems) not use cases of the components themselves. This abstraction is usually very critical to managing complexity. Abstraction allows us to retain the higher level picture without polluting it with downstream choices. Abstraction reduces volatility while retaining clarity of need vs design.