Page 164 - Software and Systems Requirements Engineering in Practice

130 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

5.2 An Integrated Model
As was discussed in Chapter 2, integrated requirements engineering
revolves around an integrated artifact model. Figure 5.1 shows the
artifact model that we will use as a guide for this chapter. It shows the
artifacts and relationships that integrate functional and architectural
requirements engineering disciplines.
In this model, the two subdisciplines (functional and architectural
requirements) share artifact types, and specific artifacts, wherever
possible. Where this is not possible, trace relationships are established
between the artifacts so that consistency and completeness checks can
be carried out as needed. In many cases, the integration is achieved by
introducing new subclasses of existing artifact classes. For example,
quality attribute requirements are a kind of system requirement and as
such are applied to system use cases and system use case scenarios in
the same way as functional requirements. On the other hand, a quality

Architecture Requirements Artifacts
Problem Statement
• Business Case
• Market Analysis Satisfice Customer
• Business Drivers Requirements
• Business Requirements
• Etc.
Implied by (scopes) Satisfice
Engages
Stakeholders Can be Use Cases
QAW Participate
Elicits Exemplify Actors
concerns of inferred from Exemplify Satisfy
Apply to
Formalize
Quality Attribute
Scenarios Use-case Scenarios
Generalize/
Generalize
exemplified by Apply to
Factors Quality Attribute Requirement
Exemplified by
System
Exemplify Means Contrast/ Requirements • Take Measurement
"Partially Define by juxtapose • Exceed Provisional Target
Example"
Verify
Issues
• Conflicts Between Factors
Test Cases
Address
Allocates
Strategies responsibility for
Architecture
Design Employ
Architecture Principles
• "Grammar" Conforms to
• "Semantics" Product Architecture
• View Models
• Decisions Tests
• Etc.
Implements
Design
Implements
Code
FIGURE 5.1 Architectural requirements engineering artifacts