This section introduces the software requirements process, orienting the remaining five subareas and showing how the requirements process dovetails with the overall software engineering process.
2.1. Process Models
The objective of this topic is to provide an understanding that the requirements process
Is not a discrete front-end activity of the software life cycle, but rather a process initiated at the beginning of a project and continuing to be refined throughout the life cycle
Identifies software requirements as configuration items, and manages them using the same software configuration management practices as other products of the software life cycle processes
Needs to be adapted to the organization and project context
In particular, the topic is concerned with how the activities of elicitation, analysis, specification, and validation are configured for different types of projects and constraints. The topic also includes activities which provide input into the requirements process, such as marketing and feasibility studies.
2.2. Process Actors
This topic introduces the roles of the people who participate in the requirements process. This process is fundamentally interdisciplinary, and the requirements specialist needs to mediate between the domain of the stakeholder and that of software engineering. There are often many people involved besides the requirements specialist, each of whom has a stake in the software. The stakeholders will vary across projects, but always include users/operators and customers (who need not be the same).
Typical examples of software stakeholders include (but are not restricted to)
Users: This group comprises those who will operate the software. It is often a heterogeneous group comprising people with different roles and requirements.
Customers: This group comprises those who have commissioned the software or who represent
the software’s target market.
Market analysts: A mass-market product will not have a commissioning customer, so marketing people are often needed to establish what the market needs and to act as proxy customers.
Regulators: Many application domains such as banking and public transport are regulated. Software in these domains must comply with the requirements of the regulatory authorities.
Software engineers: These individuals have a legitimate interest in profiting from developing the software by, for example, reusing components in other products. If, in this scenario, a customer of a particular product has specific requirements which compromise the potential for component reuse, the software engineers must carefully weigh their own stake against those of the customer.
It will not be possible to perfectly satisfy the requirements of every stakeholder, and it is the software engineer’s job to negotiate trade-offs which are both acceptable to the principal stakeholders and within budgetary, technical, regulatory, and other constraints. A prerequisite for this is that all the stakeholders be identified, the nature of their “stake” analyzed, and their requirements elicited.
2.3. Process Support and Management
This topic introduces the project management resources required and consumed by the requirements process. It establishes the context for the first subarea (Initiation and scope definition) of the Software Engineering Management KA. Its principal purpose is to make the link between the process activities identified in 2.