Resumen capítulo 2

Chapter 2: Lifecycle Types and Their Rationales

Author: James Cadle
Resource: Developing Information Systems: Practical Guidance for IT Professionals

This chapter introduces different System Development Lifecycles (SDLCs) and their application. It explores linear and evolutionary approaches, Agile, and hybrid methods, helping to decide the best approach.

Key Concepts

What is an SDLC?

An SDLC is a framework guiding the stages of system development, including feasibility study, requirements, design, development, testing, and implementation. These stages ensure structured and efficient system delivery.

Linear vs. Evolutionary Approaches

• Linear: Follows a sequential flow (e.g., Waterfall, V-Model). Best for stable requirements but less adaptable to change.
• Evolutionary: Iterative and adaptive (e.g., Spiral, Agile). Ideal for unclear requirements or innovation.

Lifecycle Examples

1. Waterfall: Rigid and step-by-step. Strong for well-defined projects but struggles with changing requirements.
2. V-Model: Enhances testing and quality assurance. Suitable for safety-critical systems.
3. Incremental: Delivers functionality in parts, allowing earlier customer feedback.
4. Spiral: Focuses on risk reduction through iterations and prototypes.
5. Agile: Collaborative and iterative. Excellent for fast-changing environments but requires close customer involvement.

Impact of Agile

Agile revolutionized SDLCs with its focus on collaboration, adaptability, and delivering working software quickly. While effective for small teams, challenges arise in regulated environments or large-scale projects.

Choosing the Right Approach

Selecting an SDLC depends on factors like:

• Complexity: Simple problems suit Waterfall; complex ones may need Spiral or Agile.
• Team Experience: Familiarity with the approach often ensures success.
• Requirements Stability: Stable requirements favor linear methods; evolving ones need iterative approaches.
• Customer Involvement: High involvement from customers fits with Agile; low involvement aligns with linear models.

By tailoring the SDLC to the project’s needs, organizations can balance flexibility, quality, and efficiency effectively.