Requirements Engineering PPT 2

RE Process

Takes and input, gives an output

Consists a set of Activities

Garbage process, Garbage product

Basic evolutionary process

Just Know we have Old Reality, Model, Implementation and also New Reality, Model, Implementation

In the Basic Evolutionary Process, How can we ensure the changes in New Model correctly reflect in the New Implementation

Traceability, make sure each requirement matches up with code and vice-versa

Forward Traceability

Each Requirement matches up with some code

Backward Traceability

Each piece of code matches up with a requirement

A Basic Framework

Elicitation → Specification → Validation

Elication

what, when, where, who, why

Spiral Model

Elicitation → Analysis & Negotiation → Documentation → Validation

How is Spiral Model different from Basic Framework

Spiral is Iterative and adds analysis/negotiation

Role Actor Diagram

A special iterative process extending the RE Framework

RE Process Maturity Model

Based on CMM CMMI

5 Levels:

1. Initial: Ad-hoc Chaos

2. Repeatable: Standard SED Requirements

3. Defined: Processes defined for best practice

4. Managed: Measured and Controlled Quality

5. Optimized: Continuous process improvement through feedback

IEEE Standard for SRS

1. Introduction (Purpose, Scope)

2. Overall Description (Product Perspective, Constraints, Assumptions)

3. Specific Requirements (Requirements & more constraints)

How is IEEE SRS Standard different from WRS

IEEE describes what the software should do, while WRS shows how it should interact with the world

RE V-Model

Every development phase has an equal validation phase making sure each req is met at each level