The phases are never folded. For each one, what the machine produces and what a person stamps are fixed. The next phase does not start until the stamp is on.
No.PhaseWhat happens in this phaseWhat the machine producesWhat a person stamps
01RequirementsBusiness needs are reconciled with current constraints, and what will be built is fixed in writing. Nothing ambiguous moves forward.What the machine producesRequirements specification, business flows, glossary and moreWhat a person stampsCheck stamp
02Basic designThe skeleton of screens, reports, the database and external integrations is decided. What is decided here becomes the baseline for everything after.What the machine producesScreen design, report design, database design, interface design and moreWhat a person stampsCheck stamp
03Detailed designProcessing is written out in full along the chapter structure. Existing code is the evidence, and anything inferred is marked "unverified".What the machine producesDetailed design by chapter, processing specifications, the evidence-line listingWhat a person stampsCheck stamp per chapter
04ImplementationWritten exactly as designed. The unit test code comes out at the same time, so design and implementation do not drift.What the machine producesSource, unit test code, implementation notesWhat a person stampsCheck stamp
05TestingFour stages: unit, integration, system and acceptance. Each defect report links back to the design phase that caused it.What the machine producesTest plans, test specifications, reports, defect management recordsWhat a person stampsCheck stamp per stage
06Migration & releaseThe migration and rollback procedures are produced and shipped to production. This is the only place that needs two approvals.What the machine producesMigration plan, release procedure, rollback procedureWhat a person stampsTwo stamps (PM + Operations)
07Operations & maintenanceOperation is monitored, and incidents and changes are handled. Each maintenance item is raised as an issue, and a job (one run for one issue) takes it through the same seven phases.What the machine producesOperating procedures, monthly reports, incident reports, change control recordsWhat a person stampsCheck stamp
Only testing splits into four stages — unit, integration, system and acceptance. Each defect report links back to the design phase that caused it, so which design error surfaced in which test can be traced afterwards.