Software Development Lifecycle (SDLC) Cheat Sheet

Updated 2026-03-18

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The Software Development Lifecycle (SDLC) is the structured framework guiding software creation from initial concept through ongoing maintenance, encompassing planning, design, development, testing, deployment, and support phases. Modern SDLC integrates quality gates, continuous feedback loops, and automated workflows to deliver reliable software aligned with business objectives. SDLC isn't a single rigid path—it adapts through models like Waterfall, Agile, DevOps, and Spiral, each optimized for different project contexts, risk profiles, and organizational needs. Understanding SDLC phases, deliverables, and governance checkpoints is essential whether building a startup MVP, migrating enterprise systems, or implementing regulatory-compliant applications—the lifecycle provides the blueprint for predictable, maintainable software delivery.

What This Cheat Sheet Covers

This topic spans 15 focused tables and 110 indexed concepts. Below is a complete table-by-table outline of this topic, spanning foundational concepts through advanced details.

Table 1: Core SDLC PhasesTable 2: Phase DeliverablesTable 3: SDLC Models & MethodologiesTable 4: Model Selection CriteriaTable 5: Agile FrameworksTable 6: Requirements Gathering TechniquesTable 7: Design Phase ActivitiesTable 8: Testing TypesTable 9: Deployment StrategiesTable 10: Maintenance TypesTable 11: SDLC Roles & ResponsibilitiesTable 12: Documentation TypesTable 13: Quality Assurance PracticesTable 14: SDLC Metrics & KPIsTable 15: SDLC Tools & Automation

Table 1: Core SDLC Phases

Phase	Example	Description
Planning	Project charter creation Stakeholder identification	• Defines project scope, feasibility assessment, resource allocation, timeline estimation, and success criteria • establishes business case and ROI justification.
Requirements Analysis	Functional specifications User stories and acceptance criteria	• Gathers and documents what the system must do • captures business needs, user expectations, constraints, and compliance requirements through stakeholder interviews and elicitation techniques.
System Design	Architecture diagrams Database schema design	• Translates requirements into technical blueprints • defines system architecture, data models, interfaces, technology stack, security controls, and integration patterns.
Implementation (Development)	`def process_order(order):` `validate(order)` `save_to_db(order)`	• Actual code writing phase • developers build functionality according to design specs, following coding standards, version control practices, and code review processes.

Table 1: Core SDLC Phases

Phase	Example	Description
Planning	Project charter creation Stakeholder identification	• Defines project scope, feasibility assessment, resource allocation, timeline estimation, and success criteria • establishes business case and ROI justification.
Requirements Analysis	Functional specifications User stories and acceptance criteria	• Gathers and documents what the system must do • captures business needs, user expectations, constraints, and compliance requirements through stakeholder interviews and elicitation techniques.
System Design	Architecture diagrams Database schema design	• Translates requirements into technical blueprints • defines system architecture, data models, interfaces, technology stack, security controls, and integration patterns.
Implementation (Development)	`def process_order(order):` `validate(order)` `save_to_db(order)`	• Actual code writing phase • developers build functionality according to design specs, following coding standards, version control practices, and code review processes.