Requirement Engineering

Requirements Engineering (RE) is the systematic and repeatable process of defining, managing, and testing the requirements for a product. It's essentially the backbone for a successful software project, ensuring the final product actually meets the customer's needs.

What is Requirement Engineering?

• Requirement: A requirement is a function, constraint, or other property that the system must provide to fulfill the needs of its intended user(s).
• Engineering: This implies that systematic and repeatable techniques should be used.
• RE Definition: Requirements Engineering involves software engineering actions that begin with communication activity and continue into the modeling activity. The entire process creates a solid foundation for the subsequent design and construction phases.

If the software engineering team doesn't first understand the problem's requirements, the resulting software has a high probability of not meeting customer needs.

Characteristics of a Good Requirement

For software development to be a success and not a disaster, the requirements must be top-notch1. A good requirement is:

• Unambiguous & Clear: It must have only one possible interpretation 2and a standard structure3. No vague language allowed!
• Correct: It must accurately describe a real and necessary need for the customer4.
• Understandable: The meaning should be easily graspable by any reader5.
• Verifiable (Testable): A specific mechanism must exist so the requirement can be tested6. If you can't test it, you can't prove it works.
• Complete: All essential information should be present7.
• Consistent: It must not conflict with any other requirements8.
• Traceable: It can be tracked back to its origin and forward through design and code9.

Requirement Engineering Tasks

1. Inception: Establish a fundamental understanding of the core problem and the nature of the desired solution by asking "context-free" questions. This phase identifies the people who want a solution and the kind of solution desired.
2. Elicitation: Draw out the requirements from various stakeholders (customers, users, and others). The goal is to find out what the product objectives are and how the product fits into business needs.
3. Elaboration: Create a refined technical model (an analysis model) that represents the information, functional, and behavioral aspects of the requirements. This is often driven by creating and refining user scenarios describing end-user interactions.