Waterfall

aid: waterfall
x-type: concept
deliveryModel:
  model: unknown
  open_source: false
  commercial: false
  callable_host: false
  label: Delivery model not determined — needs a product licence on record
  confidence: low
  source:
  - none
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source: []
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/waterfall.png
name: Waterfall
description: Waterfall is a sequential software development methodology where progress flows steadily downward through defined
  phases including requirements, system design, implementation, testing, deployment, and maintenance. It emphasizes thorough
  documentation, fixed-scope planning, and phase-gate reviews before proceeding to subsequent stages. Waterfall remains widely
  used in regulated industries, government contracting, and projects with well-understood, stable requirements.
type: Index
url: https://en.wikipedia.org/wiki/Waterfall_model
tags:
- Project Management
- SDLC
- Software Development
- Methodology
- Software Engineering
created: '2025'
modified: '2026-05-03'
specificationVersion: '0.23'
apis: []
common:
- type: Documentation
  url: https://en.wikipedia.org/wiki/Waterfall_model
  title: Wikipedia - Waterfall Model
- type: Documentation
  url: https://www.techtarget.com/searchsoftwarequality/definition/waterfall-model
  title: TechTarget Waterfall Model Definition
- type: Vocabulary
  url: vocabulary/waterfall-vocabulary.yml
  title: Waterfall Vocabulary
- type: JSONLD
  url: json-ld/waterfall-context.jsonld
  title: Waterfall JSON-LD Context
- type: Features
  data:
  - name: Sequential Phase Execution
    description: Each phase (requirements, design, implementation, testing, deployment, maintenance) must be completed before
      the next begins, ensuring full documentation of outputs before proceeding.
  - name: Formal Phase-Gate Reviews
    description: Structured review checkpoints between phases allow stakeholders to approve progression, ensuring deliverable
      quality and scope alignment before the next stage.
  - name: Comprehensive Documentation
    description: Detailed documentation produced at each phase serves as the source of truth for subsequent phases and long-term
      system maintenance.
  - name: Fixed Scope and Requirements
    description: Requirements are gathered and locked upfront, minimizing scope creep and providing high predictability for
      cost and schedule estimates.
  - name: Clear Milestones and Deliverables
    description: Well-defined milestones at the end of each phase provide clear checkpoints for project tracking, stakeholder
      reporting, and regulatory compliance.
- type: UseCases
  data:
  - name: Government and Defense Contracts
    description: Regulated government and defense projects with fixed requirements, formal procurement processes, and strict
      documentation mandates benefit from Waterfall's structured approach.
  - name: Infrastructure and Construction Projects
    description: Large infrastructure systems with well-understood requirements and high change-management costs suit the
      sequential Waterfall model.
  - name: Compliance-Driven Software
    description: Healthcare, finance, and safety-critical systems requiring audit trails, formal verification, and regulatory
      approval align well with Waterfall's documentation-heavy phases.
  - name: Fixed-Bid Contracts
    description: Projects delivered under fixed-price, fixed-scope contracts where up-front requirements definition is essential
      for accurate cost estimation.
  - name: System Integration Projects
    description: Integrations between large enterprise systems where interface contracts must be defined and agreed upon before
      implementation begins.
- type: Integrations
  data:
  - name: Agile/Scrum
    description: Many teams adopt hybrid models combining Waterfall for high-level planning and Agile for iterative delivery
      within phases.
  - name: V-Model
    description: An extension of Waterfall that pairs each development phase with a corresponding testing phase, emphasizing
      verification and validation.
  - name: PRINCE2
    description: UK government project management framework that incorporates Waterfall concepts into structured stage-gate
      delivery.
  - name: CMMI
    description: Capability Maturity Model Integration often used alongside Waterfall in defense and aerospace software development
      programs.
  - name: DevOps
    description: Some organizations blend Waterfall for requirements and architecture with DevOps practices for continuous
      delivery in later phases.
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com