Introduction to SDLC

✅ 1. What is SDLC?

📌 Definition:

The Software Development Life Cycle (SDLC) is a structured process used to design, develop, test, deploy, and maintain software systems. It provides a systematic approach to ensure high-quality software is delivered on time and within budget.

💡 In simple terms: SDLC is the roadmap that guides software development from start to finish.

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🎯 2. Purpose and Importance of SDLC

Purpose	Why It Matters
Organize development process	Provides a clear roadmap and structure.
Improve software quality	Ensures systematic testing and validation.
Manage time and cost	Enables better planning, scheduling, and budgeting.
Reduce risks	Identifies issues early and allows mitigation.
Enhance communication among teams	Clear roles, responsibilities, and deliverables.

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✅ 3. Phases of the Software Development Life Cycle

Phase	Description	Key Activities
1. Planning	Define project goals, scope, and resources.	Feasibility study, budgeting, timeline estimation.
2. Requirements Analysis	Gather and document what the system must do.	Requirements elicitation, stakeholder interviews, documentation (BRD, FRD).
3. Design	Plan how the system will be built.	Architecture design, data models, UI/UX design.
4. Development (Coding)	Actual creation of the software product.	Coding, unit testing, integration.
5. Testing	Check if software meets requirements and is defect-free.	Functional, integration, system, user acceptance testing (UAT).
6. Deployment	Release the software for use.	Go-live, rollout, installation, user training.
7. Maintenance and Support	Ongoing updates and bug fixes.	Monitoring, enhancements, patches.

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✅ 4. Role of Business Analyst in SDLC

Phase	BA's Role
Planning	Help define project goals and identify stakeholders.
Requirements Analysis	Gather, analyze, and document business and system requirements.
Design	Collaborate with technical teams to ensure design aligns with requirements.
Development	Clarify requirements for developers, answer questions.
Testing	Validate test cases, participate in UAT, ensure requirements are met.
Deployment	Support change management, training, and communication.
Maintenance	Gather feedback for future improvements.

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✅ 5. SDLC Models / Methodologies

Model	Description	When to Use
Waterfall	Sequential, each phase must finish before the next.	Well-defined, stable requirements.
Agile	Iterative, incremental development in sprints.	Changing requirements, need for flexibility.
Spiral	Combines iterative development with risk analysis.	High-risk, large projects needing risk control.
V-Model (Validation & Verification)	Testing activities are planned in parallel with development.	High reliability and testing focus.
Iterative	Repeated cycles of development and refinement.	Evolving requirements, gradual improvement.
DevOps	Focus on collaboration between development and operations for continuous delivery.	Continuous integration/deployment.

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✅ 6. Common Tools Used in SDLC

Purpose	Tools
Requirement Management	Jira, Confluence, Trello, IBM DOORS
Design and Modeling	Lucidchart, Figma, Visio, Draw.io
Code Repositories	GitHub, GitLab, Bitbucket
Testing and QA	Selenium, JUnit, TestRail, Postman (API Testing)
Project Management	Asana, Monday.com, Microsoft Project
CI/CD (Continuous Integration/Deployment)	Jenkins, Azure DevOps, GitHub Actions

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✅ 7. Benefits of Following SDLC

Benefit	Impact on Project
Structured approach	Reduces chaos, improves predictability.
Higher quality software	Well-tested, validated solutions.
Risk mitigation	Problems identified early.
Better communication	Clear expectations among stakeholders.
Efficient resource utilization	Optimize time, budget, and team efforts.
Improved customer satisfaction	Meeting user needs and delivering value.

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✅ 8. SDLC vs Agile: What's the Difference?

Aspect	Traditional SDLC (e.g., Waterfall)	Agile SDLC
Process	Linear, sequential	Iterative, incremental
Flexibility	Rigid, difficult to change mid-project	Highly flexible, adaptive to change
Customer Involvement	Limited, mostly at start and end	Continuous feedback and involvement
Deliverables	One final product at the end	Working software in each sprint/iteration
Risk Handling	Risks identified during planning	Risks addressed throughout iterations

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✅ 9. Example of SDLC in Action: Developing a Mobile Banking App

Phase	Example Activity
Planning	Identify target users, define project scope.
Requirements Analysis	Gather needs: money transfers, bill payments.
Design	Create wireframes, system architecture.
Development	Code front-end and back-end functionalities.
Testing	Test login, transactions, security.
Deployment	Launch app on App Store and Google Play.
Maintenance	Release updates, fix bugs, add new features.

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✅ 10. Summary of SDLC

Aspect	Explanation
Definition	Structured process to develop software.
Key Phases	Planning, Requirements, Design, Development, Testing, Deployment, Maintenance.
Role of BA	Ensure solutions meet business needs at every step.
Popular Models	Waterfall, Agile, Spiral, V-Model.
Benefits	Quality, predictability, risk management.