What is a requirements list and what are the challenges involved in its creation?
The presentation of requirements in tabular form
There are two different definitions for the requirements list: formally speaking, a requirements list is only created at the beginning of the development activity. It is based on the system or software requirements specification and is a tool for searching and evaluating solutions that fulfill requirements. Colloquially and widely used, the requirements list is simply a tabular representation of requirements.
In business practice, the requirements list and the requirements catalogue are often used synonymously. Formally also the requirement catalogue lists requirements, however, such requirements become an input into a customer requirement specification. The essential differences lie therefore in the time of the production – before the customer requirement specification and/or after the system or software requirement specification – and in the creator – client and/or contractor.
Challenges when working with requirements lists
There are various challenges and questions when working with requirements lists. Here is a small selection:
- Which attributes are defined for each requirement? Is mapping between client and contractor information required? Example: Does the customer define a requirement number, is this taken over or does the contractor use his own number range and has to map corresponding requirement numbers?
- How are the requirements prioritized? This question is usually more difficult to answer for a contractor than for a client, since the latter usually defines almost all requirements in a customer requirement specification as “must” or “should” requirements according to the MoSCOW method.
- Which tool is used to work with the requirements? Especially with extensive requirement lists with numerous dependencies between the requirements, with possible changes in the course of the development, with the common work on requirements and the list, with the progress tracking, or in industries with proof duties and high requirements to traceability and revision security, “on-board tools” are often not sufficient.
- How does the implementation planning, implementation and testing take place on the basis of the requirements list?
Many companies have extensive knowledge of working with requirement lists. Experience shows that clients and contractors should clarify with each other what they understand by which term and what mutual expectations prevail. The V-Modell XT as a German standard for the development of software and systems defines e.g. a common set of terms, recommends the work with two projects – one project on each side – and the transfer of work results at fixed times.