Requirements Engineering Process

Transcription

1 Domain understanding and elicitation Evaluation and agreement Specification and documentation Requirements consolidation Requirements Engineering Process CS/SE 3RA3 Ryszard Janicki Department of Computing and Software, McMaster University, Hamilton, Ontario, Canada Ryszard Janicki Requirements Engineering Process 1/8

2 Domain understanding and elicitation Evaluation and agreement Specification and documentation Requirements consolidation Previous Lecture: Non-Functional Requirements Non-functional : constrain how such services should be provided Look and Feel Requirements Usability Requirements Performance Requirements (include Safety critical ) Operational Requirements Maintainability and Portability Requirements Security Requirements (different than Safety Requirements) Cultural and Political Requirements Legal Requirements Open Issues Off-the-Shelf Solutions The case of Elevator System was discussed. Ryszard Janicki Requirements Engineering Process 2/8

3 Domain understanding and elicitation Evaluation and agreement Specification and documentation Requirements consolidation The requirement engineering process 1 Domain understanding and elicitation 2 Evaluation and agreement 3 Specification and documentation 4 Validation and verification The entire process can (and usually is) repeated many times! Ryszard Janicki Requirements Engineering Process 3/8

4 Domain understanding and elicitation Domain understanding Studying the system-as-is Identifying the system stakeholders Requirements Elicitation The RE process (1)

5 Evaluation and agreement Negotiation based decision making The goal is to produce final sections of draft proposal documenting the selected/agreed objectives,, assumptions (incl. rationale for selected options) The RE process (2) evaluation & agreement agreed

6 Specification and documentation Precise definition of all features of the agreed system Organization of these in a coherent structure Documentation in a form understandable by all parties Resulting product: Requirements Document (RD) The RE process (3) evaluation & agreement agreed specification & documentation documented

7 Requirements consolidation Quality assurance activity on RD Validation: adequacy of RD items wrt real needs? Verification: omissions, inconsistencies? Verification: omissions, inconsistencies? Checks for other target qualities (discussed next) Fixing of errors and flaws Products: Consolidated RD, Acceptance test data, prototype, Development plan, Project contract The RE process (4) evaluation & agreement consolidated validation & verification agreed specification & documentation documented

8 Domain understanding and elicitation Evaluation and agreement Specification and documentation Requirements consolidation RE: an iterative process RE phases are ordered by data dependencies No strict sequencing: intertwining, overlap, backtracking Iterated cycles due to error corrections & evolving needs during RE, during software development, after deployment evaluation & agreement consolidated validation & verification agreed specification & documentation documented Ryszard Janicki Requirements Engineering Process 8/8