04-01-2013, 10:38 AM
Requirements Engineering Processes
Requirements Engineering.ppt (Size: 1.15 MB / Downloads: 19)
Objectives
To describe the principal requirements engineering activities and their relationships
To introduce techniques for requirements elicitation and analysis
To describe requirements validation and the role of requirements reviews
To discuss the role of requirements management in support of other requirements engineering processes
Requirements engineering processes
The processes used for RE vary widely depending on the application domain, the people involved and the organisation developing the requirements.
However, there are a number of generic activities common to all processes
Requirements elicitation;
Requirements analysis;
Requirements validation;
Requirements management.
Feasibility studies
A feasibility study decides whether or not the proposed system is worthwhile.
A short focused study that checks
If the system contributes to organisational objectives;
If the system can be engineered using current technology and within budget;
If the system can be integrated with other systems that are used.
Feasibility study implementation
Based on information assessment (what is required), information collection and report writing.
Questions for people in the organisation
What if the system wasn’t implemented?
What are current process problems?
How will the proposed system help?
What will be the integration problems?
Is new technology needed? What skills?
What facilities must be supported by the proposed system?
Elicitation and analysis
Sometimes called requirements elicitation or requirements discovery.
Involves technical staff working with customers to find out about the application domain, the services that the system should provide and the system’s operational constraints.
May involve end-users, managers, engineers involved in maintenance, domain experts, trade unions, etc. These are called stakeholders.
Problems of requirements analysis
Stakeholders don’t know what they really want.
Stakeholders express requirements in their own terms.
Different stakeholders may have conflicting requirements.
Organisational and political factors may influence the system requirements.
The requirements change during the analysis process. New stakeholders may emerge and the business environment change.
Requirements discovery
The process of gathering information about the proposed and existing systems and distilling the user and system requirements from this information.
Sources of information include documentation, system stakeholders and the specifications of similar systems.
Effective interviewers
Interviewers should be open-minded, willing to listen to stakeholders and should not have pre-conceived ideas about the requirements.
They should prompt the interviewee with a question or a proposal and should not simply expect them to respond to a question such as ‘what do you want’.