Agile guide · Agile foundations
Agile Development Life Cycle: The 6 Phases Explained Simply
The Agile development life cycle is the sequence of stages a product moves through when it is built with Agile methods: from a first idea, through repeated short iterations that each deliver working results, to release, support and eventual retirement. Unlike a linear life cycle, the building stage loops many times, with feedback shaping each pass.
Key takeaways
- The Agile life cycle runs from concept and inception, through repeated iterations, to release, maintenance and retirement.
- Planning, building and testing happen together in every iteration rather than in separate phases.
- Release early increments to gain feedback, and plan capacity for maintenance work.
- There is no single official model, so adapt the phase names to your context.
What the Agile life cycle is
A life cycle describes how work flows from idea to finished product. In a Waterfall life cycle each phase (requirements, design, build, test, deploy) happens once, in order. In Agile, planning, design, building and testing happen together inside every short iteration, and the product grows in increments. The phases below describe the product's journey as a whole; most of the time is spent in the iteration phase.
The six phases
| Phase | What happens | Typical outputs |
|---|---|---|
| 1. Concept | Identify the opportunity, the users and the outcome you want; decide whether it is worth exploring | Problem statement, rough scope, go/no-go decision |
| 2. Inception | Form the team, agree the product vision, build an initial backlog and set up tools and environments | Product vision, first product backlog, team working agreement |
| 3. Iteration (construction) | Plan, build, test and review small slices of value in repeated sprints or a continuous flow | Working, tested increments; feedback; an updated backlog |
| 4. Release | Final checks, documentation and training, then deployment to users | Released product or feature set |
| 5. Maintenance (production) | Support users, fix defects and keep improving the product, usually with further iterations | Fixes, enhancements, operational data |
| 6. Retirement | Withdraw the product, migrate users and data, and close down support | Decommissioning plan, archived data |
How one iteration works
- Plan: the team picks the highest-value items from the backlog and agrees a goal for the iteration.
- Design and build: developers, testers and designers work together on each item rather than handing work along a chain.
- Test: testing happens continuously, so each item meets the Definition of Done before it is counted as finished.
- Review: the team shows the working result to stakeholders and gathers feedback.
- Reflect: in a retrospective the team agrees one or two improvements to how it works.
- Adapt: feedback and new information update the backlog, and the next iteration begins.
Worked example: a booking app
A gym chain wants members to book classes online.
- Concept (1 week): the product manager confirms that phone bookings take staff around 20 hours a week and sets a goal of moving most bookings online.
- Inception (2 weeks): a team of six forms, writes a vision and creates 40 user stories grouped into four epics.
- Iterations (6 two-week sprints): sprint 1 delivers a simple class timetable; sprint 2 adds booking and cancellation; later sprints add waiting lists, reminders and payments.
- Release: after sprint 3 a basic version goes live at two pilot gyms; after sprint 6 it is rolled out to all sites.
- Maintenance: the team keeps a smaller capacity for fixes and new features based on usage data.
- Retirement: years later the app is replaced by a new member platform and the old booking data is migrated.
Agile life cycle vs traditional SDLC
| Traditional (Waterfall) SDLC | Agile life cycle | |
|---|---|---|
| Order of work | Phases happen once, in sequence | Build phases repeat in short iterations |
| Requirements | Fixed up front | Evolve in a prioritised backlog |
| Testing | A separate phase near the end | Continuous, inside each iteration |
| Delivery | One release at the end | Frequent increments, often released early |
| Change | Controlled through formal change control | Expected and absorbed through the backlog |
| Customer involvement | Mainly at the start and end | Throughout, at every review |
See Agile vs Waterfall for a fuller comparison.
Common mistakes
- Mini-Waterfall sprints: doing all design in one sprint, all build in the next and all testing after that.
- Skipping inception: starting sprints without a shared vision, so the backlog drifts.
- Never releasing: building many increments but holding them back for one big launch, losing the feedback that makes Agile work.
- Forgetting maintenance capacity: planning every sprint as if there were no support work.
- Ignoring retirement: leaving old products running with no owner or plan.
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Frequently asked questions
What are the phases of the Agile development life cycle?
A common model has six phases: concept, inception, iteration (construction), release, maintenance (production) and retirement.
Is the Agile life cycle the same as the SDLC?
The software development life cycle (SDLC) is a general term for the stages of building software. The Agile life cycle is one way of running the SDLC, with the build stages repeated in short iterations.
Which phase of the Agile development life cycle takes the longest?
The iteration phase, because the team repeats it many times, often continuing after the first release.
How long is an iteration in the Agile development life cycle?
Usually one to four weeks. Many teams use two-week sprints.
Does the Agile development life cycle have a design phase?
Not a separate one. Design happens continuously inside each iteration, with some high-level design done during inception.
Where does testing happen in the Agile life cycle?
Inside every iteration. Work is not counted as finished until it is tested and meets the Definition of Done.
Is Scrum an Agile development life cycle?
Scrum is a framework for running the iteration phase. It does not define concept, release or retirement phases; see what is Scrum.
Can you release before the end of the Agile life cycle?
Yes, and it is encouraged. Releasing early increments brings real user feedback sooner.
What happens in the inception phase of the Agile life cycle?
The team forms, agrees a product vision, sets up tools and environments and creates an initial product backlog.
How does Kanban fit the Agile life cycle?
Kanban teams replace fixed iterations with a continuous flow of work, but the overall journey from concept to retirement is the same; see what is Kanban.
Do non-software teams use the Agile life cycle?
Yes. Marketing, creative and other teams use the same idea of short cycles that deliver usable results and gather feedback; see is Agile only for software.