Software Engineering

168
CHAPTER 9 
Software Requirements Management
●
  What are the best-case, probable, and worst-case scenarios associated with 
an attempt to satisfy a requirement?
●
  How can the requirement be restated to eliminate or diminish the risks it 
imposes to project success?
9.3 
Requirement decomposition and allocation
Initial software requirements are generally a substantial, complex covenant against 
which the delivered product is to be qualified. Every requirement must be translated 
in form from natural language into a set of design features, characteristics, or quality 
attributes of the software product that can be implemented. This fundamental prem-
ise differentiates software engineering, as described in this book, from existing soft-
ware development methodologies or practices. The translation of a requirement into 
a design requires the application of software engineering practices to design, plan, 
implement, and sustain software products. Beginning with software requirements, the 
technical organizations must collaborate to establish a software product architecture 
that can be implemented, tested, and sustained. Requirements must be able to be traced 
throughout the product architectural design, test cases and procedures, technical plans, 
and control mechanisms. This traceability facilitates the technical team’s responsive-
ness to proposed changes to stakeholder needs, software requirements, or design chal-
lenges. 
Figure 9.2
 identifies the requirement decomposition and allocation flow.
Stakeholder Needs
& Expectations
Operational Model
Change
Proposals
Software Requirement
Specifications
(Requirements Analysis)
Product Functional
Architecture
(Functional Analysis &
Allocation)
Change
Requests
Product Physical
Architecture
(Design Synthesis)
Product
Configuration
Audit (PCA)
Software Product
Image(Release)
Software Product
Image(Testing)
Software Test
Procedures
Software
Implementation
Software Test Plan
(Test Cases)
Functional
Configuration
Audit (FCA)
Project Management Controls
Technical Management Controls
WBS
Work Packages
Traceability Database
Technical Change Control
Board
Technical Management Plan
& Schedule(TMP/TMS)
Risk Database
Change Control Board
Integrated Management Plan
& Schedule(IMP/IMS)