Page 57 - Software and Systems Requirements Engineering in Practice

30 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

Business Contains Business
Plan * Goal
Assist in meeting
Marketing Describes Has
Brochure 1..* Product * Feature
Meet the needs of
1..*
May submit Stakeholder May become Customer Market Requirement
Customer Request 1..* Requirement Specification
* * 1..* * Contains 1
Tests * Augmented with Used to create
*
Contains Tests System
Test Plan Test Case Design
* 1..* Requirement
Contains
System Requirement Used to create
Specification
FIGURE 2.10 Example requirements engineering artifact model

2.4 Using the Artifact Model
The artifact model that is created prior to the start of a project is like
looking at the X-ray of a patient prior to starting surgery. The model
is used by most stakeholders (except possibly customers). Examples
of the RE artifacts that will be used by the various roles of a
development project are given in Table 2.1.

Extending an Artifact Model to Augment Process Definition
Artifact models can be extended to support process definition. For
example, we may add artifacts such as completion status, decision
gates, checklists, etc. (Figure 2.11). At the beginning of a project, a
draft artifact model is created. The model is then used to define the
product life cycle processes. After review, the artifact model and the
defined processes are continually updated. While the upfront costs of
creating a model may appear high, in our experience it is a very fast
and cost-effective activity. Furthermore, just having project staff think
about downstream artifacts, quality gates, and approval checklists
can result in significant efficiencies.

2.5 Using Templates for Requirement Artifacts
A suggested way to get started creating a REAM is to use a template
to fill in the information about each artifact in the model. A sample
template is shown in Figure 2.12.
The template is filled out for each artifact and then maintained
with the same tool used to create the drawings. As mentioned
previously, commercial tools are available; however, for a staff with