Requirement Dependencies

Dependencies build upon linking by tracking an order in which requirements should be built.

While linking requirements together forms the traceability matrix and ensures output correctness, dependencies form the bonds between requirements of the same type.

Example

For example, let us use an example requirement setup with this subset of requirements:

Stakeholder Requirement 1 : The train must be the fastest mode of transportation from Los Angeles to Las Vegas.

System Non-Functional Requirement 1 : The train must complete a one-way trip from Los Angeles to Las Vegas in at most 2 hours. Reasoning: this is to be faster than an airplane flight, including security checks.

System Functional Requirement 1 : The train must be capable of traveling at least 150mph

System Functional Requirement 2 : The train must have doors to allow passengers to enter and exit the interior seating area.

System Functional Requirement 3 : The train must be capable of carrying at least 100 passengers.

System Functional Requirement 4 : The same doors must be used for loading and unloading passengers.

System Functional Requirement 5 : The train must have safety features on passenger doors to prevent avoidable injuries.

Technical Requirement 1 : Ultrasonic sensors will be used on all sides of the train door to detect any animal in the way of opening and closing.

Technical Requirement 2 : Servos capable of full bidirectional rotation are chosen to ensure doors can move in two directions.

Example dependencies

The System Functional Requirements for door functionality (System Functional Requirements 3, 4, 5) would be dependent on System Functional Requirement 2, because the need for doors creates the dependency on how the doors must function.

The requirements around train speed (System Functional Requirement 1) would not be dependent on the other System Functional Requirements listed in the example, since it is not relating to a functionality of the door.