Use a Gantt chart to manage your software development lifecycle. Plan requirements, design, development, testing, and deployment phases with clear timelines and dependencies.
A software development lifecycle looks simple on paper: gather requirements, design, build, test, deploy. In practice, each phase bleeds into the next, developers block on design decisions, QA can't start until features are code-complete, and stakeholders want status updates you can't give because you have no shared view of where things stand.
A software development lifecycle Gantt chart gives every phase a start date, end date, and dependency chain. You can see when QA needs to ramp up before development finishes, which features are on the critical path, and whether a two-week slip in design puts the launch date at risk. gantt-chart.io lets dev teams build this in minutes—free, no sign-up, shareable with your entire team.
Before building your SDLC Gantt chart:
| Phase | Typical Duration | Key Output |
|---|---|---|
| Requirements gathering | 1–3 weeks | PRD, user stories |
| System design | 1–2 weeks | Architecture docs, wireframes |
| Development (sprints) | 4–12 weeks | Working code |
| Integration testing | 1–2 weeks | Test reports |
| UAT | 1–2 weeks | Signed off features |
| Staging deployment | 3–5 days | Staging release |
| Production release | 1–3 days | Live product |
| Post-launch stabilization | 1–2 weeks | Bug fixes |
Each SDLC phase is a parent bar in your Gantt. Under each parent, break down the actual work:
Requirements phase tasks:
Design phase tasks:
Development phase tasks (per sprint):
Testing phase tasks:
Deployment phase tasks:
SDLC phases have hard sequential dependencies:
Add these dependency arrows in your Gantt so any schedule change automatically shows its downstream impact.
The critical path is the longest chain of dependent tasks. In most SDLC projects, it runs through:
Requirements → Architecture → Core feature development → Integration testing → UAT → Production deploy
Any slip on the critical path slips the release date. Tasks off the critical path have float—they can slip without affecting the launch.
Every bar needs an owner. In a Gantt chart, that means:
Compressing testing to protect the launch date. Testing time is not a buffer. When development runs long, teams cut QA time—and ship bugs. Block QA time as fixed in your Gantt and let development adjust around it.
No time for bug fixes after testing. Testing always finds bugs. Budget 20-30% of your testing window for fix-and-retest cycles in your Gantt.
Ignoring environment setup time. Staging environments don't configure themselves. Add explicit tasks for environment provisioning, data migration, and smoke testing—these take days, not hours.
Parallel work without resolving dependencies. Two teams building features that share a database schema can't both be "in progress" without coordinating. Map the dependency explicitly.
A sprint board (Scrum board, Kanban) shows you what's in progress right now. A Gantt chart shows you whether the project will finish on time. You need both:
Week 1-2: Requirements (interviews, stories, PRD)
Week 2-3: Design (architecture, wireframes, API contracts)
Week 4-9: Development (3 x 2-week sprints)
Week 9-10: Integration testing + bug fixes
Week 10-11: UAT
Week 11: Staging deployment + smoke test
Week 12: Production release + stabilizationBuild this template at gantt-chart.io—free, no sign-up, export to PNG or share via link.
Small project (1-3 developers, 4-6 weeks): Compress phases. Requirements and design can overlap. Testing and UAT can run concurrently. The Gantt still matters—you just have fewer bars.
Large project (10+ developers, 6+ months): Add swim lanes per team or module. Track parallel development streams. Use milestones for phase gates. Show external dependencies (third-party APIs, vendor deliverables) as tasks with assigned owners.
Mark these as diamond milestones in your Gantt:
Milestones give stakeholders clear checkpoints without needing to understand every underlying task.