• Table of Contents

Requirements Engineering Lifecycle

The RE Lifecycle is a process that involves activities for identifying, analyzing, specifying, validating, and managing the requirements of a system.

Figure 3.1 RE Lifecycle.

These phases are not necessarily sequential, and there may be overlap and iteration between them.

1. Elicitation: The process of identifying the requirements for a system by gathering information from stakeholders, users, and other sources.
2. Analysis: The process of understanding and analyzing the requirements that have been identified during the elicitation phase. This involves breaking down the requirements into smaller, more manageable pieces and identifying any conflicts or inconsistencies.
3. Specification: The process of documenting the requirements in a clear and unambiguous way. This can be done using various techniques such as natural language, use cases, and formal models.
4. Evaluation: The process of ensuring that the requirements are complete, consistent, and meet the needs of the stakeholders. This involves reviewing the requirements with stakeholders and performing various testing activities to validate the requirements.

The RE Lifecycle is an ongoing process that continues throughout the development of the system, with requirements being refined and updated as needed.

Requirement Inception

As we briefly covered in Week 2, requirement inception is the initial short step to establish a common vision about the product and basic scope for the project.

Activities and Artifacts in the Inception Phase

Some of the activities and artifacts typically associated with the inception phase are listed below.

• Activity:
  1. Define scope: Define the boundaries of the proposed system and determine what is included and excluded.
  2. Perform feasibility study: Determine whether the proposed system is feasible from technical, economic, and operational perspectives.
  3. Identify stakeholders: Identify individuals, groups, or organizations who have an interest in the proposed system.
• Artifacts:
  1. Business case: A document that outlines the business objectives and drivers for the proposed system.
  2. Use case models: A set of use cases that describe the key features and requirements of the proposed system.
  3. Risk list: A document that identifies potential risks associated with the proposed system, assesses their impact and likelihood, and provides recommendations on how to mitigate or manage them.

The specific activities and artifacts may vary depending on the methodology or framework used.

Preliminary Investigation

The preliminary investigation model begins to evaluate the business opportunity or problem.