Requirements

Requirements are the starting point of any project and is very often neglected because it is not formally expressed. Model driven development introduces high level diagrams such as Use cases and Sequence diagrams to help formalize the requirements written in natural language. These diagrams can be later re-used in the development process in order to check conformance to the requirements.

A Use case diagram

Actors are identified as well as how they interact with the system.

A High Level MSC diagram

High level Message Sequence Chart editor allows to organize scenarios and define how they relate to one another: scenarios can be executed in parallel or in sequence.

A Sequence diagram

Sequence Diagrams or Message Sequence Charts provide a detailed description of a scenario. Each object, semaphore or task is seen as a line on the diagram where time flows from top to bottom. Key events in the system have a graphical representation such as :

    * Internal states modification,
    * Inputs and outputs,
    * Timers manipulation,
    * Semaphores manipulations (take and give),
    * Task creation.

A Sequence Diagram can be used to specify a behaviour or to trace system execution.

Traceability

Because the needs are very likely to evolve during the development process, it is important to be able to track the impact of any modification in the requirements. Real Time Developer Studio offers a bridge with traceability tools to handle requirements management.

Traceability information can be associated to any element of the Project Manager and exported to a traceability tool. An integration with Reqtify from TNI Software comes within our standard distribution.

RTDS requirement information

The RTDS Project appears in Reqtify.

RTDS in Reqtify

Class relations and architecture
Basic relations between actors can be sketched in a Class diagram.

Class diagram

Top level architecture of the system can be drafted as well as their interfaces. 

Architecture