Page 33 - Software and Systems Requirements Engineering in Practice

6 S o f t w a r e & S y s t e m s R e q u i r e m e n t s E n g i n e e r i n g : I n P r a c t i c e

An Effective Requirements Management Process Is in Place
The critical success factors in a requirements management process
are well defined by the Capability Maturity Model Integration
(CMMI), specifically those addressing change management and
traceability. A change control board (CCB) performs an impact analysis
and conducts cost/benefit studies when feature changes are requested.
The CCB acts as a gatekeeper to prevent unwanted “scope creep” and
ensures properly defined product releases.

Requirements Elicitation Starts with Marketing and Sales
The marketing and sales organizations and the project’s requirements
engineering staff must establish strong bonds to enable accurate
definition of product and/or product line features. Incorrect features
and requirements may be carried over into the requirements
development activities and create downstream problems.
Requirements Reviews Are Conducted for All New
or Changed Requirements or Features
Requirements must be reviewed, and the review must occur at the
right level. Since it typically takes one hour to review four to ten
requirements (e.g., for the first review—followup reviews may go
faster), reviews must be conducted at a high enough level to avoid
“analysis paralysis” and yet low enough to catch significant feature-
level defects.

Requirements Engineers Are Trained and Experienced
Requirements engineering is like any other scientific or engineering
endeavor in that the basic skills can be learned through training. But
without experienced staff, the project may “stall” or “churn” in the
requirements definition stage. If the staff is new, and the team has
more than four members, RE mentors should be used to improve the
skills of the team.
Requirements Processes Are Proven and Scalable
When processes are defined at the start of a project, they should be
bootstrapped from prior successful efforts, not just based on
“textbook” examples. As the size of a project increases, or the number
or size of work products increases, the methodologies must be scaled
to match.

Subject Matter Experts Are Available as Needed
Arrangements must be made early on to access the experts needed to
assist in defining requirements. For example, during tax season, tax