SDLC

What is SDLC?
SDLC (Software Development Life Cycle) is a step-by-step process used to develop software in a structured and efficient way.

It ensures:
High-quality software
Proper planning and execution
Reduced cost and time

SDLC Phases (Simple Understanding)
1.Requirement Gathering – Understand what the user needs
2.Design – Plan how the software will work
3.Development (Coding) – Write the code
4.Testing – Check for errors
5.Deployment – Release the software
6.Maintenance – Fix issues and update features

SDLC Models with Examples
1. Waterfall Model
Linear process (step by step, no going back)
Example:
Developing a college management system
First finalize requirements (students, marks, fees)
Then design → code → test → deploy
No changes allowed after moving forward
2. V-Model
Development + Testing side by side
Example:
Building banking software
While designing login system → also plan login testing
Each stage has a testing phase
3. Incremental Model
Build software in parts
Example:
Creating an e-commerce app
First release: Login + Product view
Second release: Add to cart
Third release: Payment system
4. Iterative Model
--> Repeated improvements
Example:
Developing a mobile app
Version 1: Basic features
Version 2: UI improvement
Version 3: Add new features based on feedback
5. Spiral Model
--> Focus on risk analysis + iteration
Example:
Developing air traffic control software
Plan → Identify risks → Develop → Test → Repeat
Each loop reduces risk
6. Agile Model
--> Flexible and fast development
Example:
Building a food delivery app
Develop small features (like login, order, tracking) in short cycles (sprints)
Continuous feedback from users
7. DevOps Model
--> Development + Operations together
Example:
Apps like online streaming platforms
Continuous updates and deployment
Automatic testing and delivery
8. Big Bang Model
--> No proper planning
Example:
A small student project
Start coding directly
Requirements may change anytime