Requirements Evaluation

Definition

Requirements evaluation (a.k.a., requirements review) is the quality control task during which the requirements work products are evaluated.

Objectives

The typical objectives of the requirements evaluation task are to:

• Determine if all specified requirements are:
  • Correct
  • Complete
  • Consistent
  • Feasible
  • Mandatory
  • Unambiguous
  • Verifiable
  • Validatable
• Determine if the deliverable requirements work products are:
  • Correct:
    • Verified with source documentation
    • Validated by stakeholders
  • Complete:
    • Containing all necessary requirements and constraints
    • Containing all required sections and subsections
  • Consistent:
    • Internally consistent (within individual requirements work products)
    • Mutually consistent (across requirements work products)
    • Externally consistent (with other work products)
    • With related conventions (e.g., standards, procedures, templates, and guidelines)
  • Understandable by their intended audiences
• Determine if all derived requirements and constraints are justified.
• Identify defects in the deliverable requirements work products so that:
  • The defects can be fixed.
  • Defect trend analysis can be performed to improve the process and staff training.
• Determine if the requirements engineering tasks are:
  • Completed
  • Effective
  • Efficient

Preconditions

The requirements evaluation task can typically begin when the following preconditions hold:

• The requirements inspection team is adequately:
  • Staffed.
  • Trained in the requirements evaluation task.
  • Trained in its associated techniques (e.g., inspection).
• At least one requirements work product is ready for evaluation.

Completion Criteria

The requirements evaluation task is typically complete when the following postconditions hold:

• The following requirements work products have passed their evaluations (e.g., inspection):
  • Requirements Executive Summary
  • System Requirements Specification
  • External API Specification
  • Glossary
  • Domain Model Document

Steps

The requirements evaluation task typically involves the following teams performing the following steps:

• The requirements team informally evaluates their work products in accordance with the associated technique used.
• The requirements inspection team evaluates these requirements work products in accordance with the associated technique(s) used.

Techniques

The requirements evaluation task can typically be performed using the following techniques:

• Model testing. (use case models)
• Quality Evaluation Techniques:
  • Desk Checking
  • Inspecting
  • Walkthroughs

Work Products

The requirements evaluation task typically results in the production of the following work products:

• Quality Set:

• Inspection Report
• Inspection Summary Report

Guidelines

• Inspecting tends to be the most effective quality evaluation technique for identifying defects.
• Evaluations can be incremental and are typically iterative.