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Agile Software Development: Process, Manifesto, Life Cycle and Scrum Explained

Updated September 2026 · Written and maintained by the Progression Agency strategy team

Agile software development is an iterative way of building software in short cycles, releasing working increments and changing course based on feedback. This guide explains the Agile Manifesto, the agile software development process and life cycle, Scrum and Kanban, lean principles, and how agile compares with waterfall — plainly, with the terms defined.

On this page · 13 sections
  1. What is agile software development?
  2. The Manifesto for Agile Software Development
  3. What is the agile software development process?
  4. The agile software development life cycle
  5. Scrum, Kanban and other agile frameworks
  6. Agile vs waterfall software development
  7. Security in the agile software development life cycle
  8. Agile and the MVP
  9. How Progression Agency uses agile
  10. Scrum roles, events and artifacts
  11. Scrum vs Kanban
  12. Agile vs waterfall at a glance
  13. Video: building products iteratively

The short answerAgile software development delivers software in short iterations, typically two-week sprints, each ending with working software that users or stakeholders can review. It follows the 2001 Manifesto for Agile Software Development, which values individuals and interactions, working software, customer collaboration and responding to change. Scrum and Kanban are the most common agile frameworks; lean software development focuses on eliminating waste and delivering value continuously.

The four values of the Agile Manifesto are summarized from agilemanifesto.org; Scrum roles and events from the Scrum Guide.

What is agile software development?

Agile software development is an approach to building software in which cross-functional teams deliver working increments in short, repeated cycles and adapt the plan based on feedback, rather than defining everything up front and delivering once at the end.

The Manifesto for Agile Software Development

Published in 2001 by seventeen software practitioners, the Agile Manifesto sets out four values and twelve principles. The values prefer the items on the left while recognizing value in those on the right.

Value — Individuals and interactions. over processes and tools..
Value — Working software. over comprehensive documentation..
Value — Customer collaboration. over contract negotiation..
Value — Responding to change. over following a plan..
Lean — Eliminate waste. Build only what adds value..
Lean — Deliver fast. Small batches, frequent releases..

What is the agile software development process?

The agile process runs in cycles: maintain a prioritized backlog, plan a sprint, build and test, hold short daily standups, demo the working increment in a review, reflect in a retrospective, release, and repeat.

The agile software development cycle
Each cycle ends with working software, so feedback arrives every two weeks instead of at the end.

The agile software development life cycle

The agile SDLC repeats concept, iteration (design, build, test), release, maintenance and feedback continuously, rather than moving once through requirements, design, build, test and deploy as in waterfall.

Agile SDLC phases
PhaseWhat happens
ConceptDefine the problem, users and goals
InceptionForm the team, set up tooling, build the initial backlog
IterationDesign, code and test in sprints
ReleaseShip increments to users
MaintenanceSupport, monitor, fix
RetirementDecommission when replaced

Scrum, Kanban and other agile frameworks

Scrum

Fixed-length sprints with three roles — product owner, Scrum Master and developers — and events for planning, daily coordination, review and retrospective. See the Scrum Guide.

Kanban

A continuous flow of work visualized on a board with limits on work in progress; no fixed sprints.

Extreme Programming (XP)

Engineering practices such as test-driven development, pair programming and continuous integration.

Lean software development

Principles from lean manufacturing applied to software: eliminate waste, build quality in, deliver fast, defer commitment and optimize the whole.

Agile vs waterfall
Waterfall suits fixed, well-understood requirements; agile suits products where learning changes the plan.

Agile vs waterfall software development

Waterfall moves through fixed phases once and delivers at the end; agile delivers working software every sprint and adjusts. Agile reduces the risk of building the wrong thing; waterfall offers more up-front predictability when requirements are fixed.

Security in the agile software development life cycle

Security is built into each sprint rather than tested at the end: threat modeling during design, code review and automated scanning on every change, and penetration testing before major releases. The NIST Secure Software Development Framework describes these practices.

Agile and the MVP

In agile, the minimum viable product is the first increment released to real users; later sprints iterate on what they do.

How Progression Agency uses agile

Our software and app development projects run in two-week sprints with a written first-release scope, an installable or deployable build at the end of every sprint, and a shared backlog you can see and reprioritize.

Scrum roles, events and artifacts

The 2020 Scrum Guide defines three accountabilities, five events and three artifacts.

Scrum at a glance (2020 Scrum Guide)
ElementWhat it isTimebox or commitment
Product OwnerMaximizes product value; owns the Product BacklogAccountability
Scrum MasterEstablishes Scrum and helps the team improveAccountability
DevelopersCreate a usable Increment each SprintAccountability
SprintFixed-length cycle of workOne month or less
Sprint PlanningDecides why, what and how for the SprintUp to 8 hours for a one-month Sprint
Daily ScrumInspects progress toward the Sprint Goal15 minutes
Sprint ReviewInspects the outcome with stakeholdersUp to 4 hours
Sprint RetrospectivePlans improvements to quality and effectivenessUp to 3 hours
Product BacklogOrdered list of what is neededProduct Goal
Sprint BacklogSprint Goal plus selected workSprint Goal
IncrementUsable step toward the Product GoalDefinition of Done

Scrum vs Kanban

Both are agile. Scrum works in fixed Sprints; Kanban manages a continuous flow of work with limits on work in progress.

Scrum vs Kanban compared
FactorScrumKanban
CadenceFixed-length SprintsContinuous flow
RolesProduct Owner, Scrum Master, DevelopersNo prescribed roles
Change during workSprint scope protectedItems can change any time
Key metricSprint Goal achieved, velocityCycle time, throughput
Best forProduct developmentSupport, maintenance, operations

Agile vs waterfall at a glance

Waterfall completes each phase before the next begins; agile repeats all phases in short cycles.

Agile vs waterfall
FactorAgileWaterfall
RequirementsEvolve with feedbackFixed up front
DeliveryWorking software every few weeksOne delivery at the end
Customer involvementContinuousMainly at start and end
Risk discoveryEarlyLate
Best forProducts with uncertaintyFixed, well-understood projects

Want to see agile in practice?

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Talk it through

Video: building products iteratively

Explainers on MVPs and iterative product development.

Getting found in search

AI, AEO and what is changing

Paid media and lead generation

Websites and design

Choosing and working with an agency

Software and app development

Social, content and brand

By industry and by situation

Frequently asked questions

What is agile software development?
An iterative approach that delivers working software in short cycles and adapts based on feedback.
What are the four values of the Agile Manifesto?
Individuals and interactions, working software, customer collaboration and responding to change, each preferred over its counterpart.
When was the Agile Manifesto written?
In 2001, by seventeen software practitioners.
What is the agile software development process?
A repeating cycle of backlog, sprint planning, build and test, daily standup, review, retrospective and release.
What is a sprint?
A fixed period, commonly two weeks, in which a team delivers a working increment.
What is the difference between agile and Scrum?
Agile is the philosophy; Scrum is a specific framework for practicing it.
What is Kanban?
An agile method that manages continuous flow of work on a visual board with work-in-progress limits.
What is lean software development?
Applying lean principles such as eliminating waste and delivering fast to software.
Agile vs waterfall: which is better?
Agile for evolving products; waterfall for fixed, well-understood requirements.
What are the phases of the agile SDLC?
Concept, inception, iteration, release, maintenance and retirement.
How is security handled in agile?
Built into every sprint through threat modeling, code review, automated scanning and testing.
What does a product owner do?
Owns the backlog and decides priorities based on value.
What is a retrospective?
A meeting at the end of a sprint to improve how the team works.
What is the difference between agile and waterfall?
Agile delivers in short iterations; waterfall moves through fixed phases once.
What is a user story?
A short description of a feature from the user’s perspective.
What is a Scrum Master?
The person who facilitates Scrum and removes obstacles.
How long is a sprint?
Commonly one to four weeks; two is typical.
What is a burndown chart?
A chart showing remaining work in a sprint.
Can agile work with fixed budgets?
Yes, by fixing time and budget and prioritizing scope.
What is DevOps?
Practices combining development and operations for fast, reliable releases.

Sources and further reading

  1. Google Search Essentials — SEO starter guide
  2. Google: creating helpful, reliable, people-first content
  3. Google: intro to structured data
  4. Google: LocalBusiness structured data
  5. Google: FAQPage structured data
  6. Google: Article structured data
  7. Google: Product structured data
  8. Google: title links in search results
  9. Google: control your snippets
  10. Google: robots.txt introduction
  11. Google: sitemaps overview
  12. Google: consolidate duplicate URLs
  13. Google: redirects and Search
  14. Google: JavaScript SEO basics
  15. Google: multi-regional and multilingual sites
  16. Google Search Central Blog
  17. Google: get started with Search Console
  18. Google: how local search results are determined
  19. Google Business Profile: prohibited and restricted content
  20. Google Business Profile: address and service area guidelines
  21. Google Business Profile: review policy
  22. Google Business Profile: add or edit categories
  23. Google Ads: location targeting settings
  24. Google Ads: about negative keywords
  25. Google Ads: about Quality Score
  26. Google Ads: importing offline conversions
  27. Google Ads: about Smart Bidding
  28. Google Ads: about Performance Max
  29. Google Local Services Ads: eligibility and screening
  30. Google Ads: keyword match types
  31. Google Analytics 4: about conversions
  32. Google Analytics 4: attribution models
  33. US Census Bureau QuickFacts: New Jersey
  34. US Census Bureau: American Community Survey
  35. US Census: Statistics of US Businesses
  36. Bureau of Labor Statistics: New Jersey data
  37. BLS: Occupational Employment and Wage Statistics
  38. NJ Department of Labor: labor market information
  39. New Jersey Business Action Center
  40. US Small Business Administration: New Jersey district
  41. USA.gov: business resources
  42. web.dev: Core Web Vitals explained
  43. web.dev: Largest Contentful Paint
  44. web.dev: Cumulative Layout Shift
  45. web.dev: Interaction to Next Paint
  46. Google PageSpeed Insights
  47. Google Rich Results Test
  48. Google Search Console
  49. W3C Markup Validation Service
  50. Schema.org: LocalBusiness type
  51. Schema.org: Service type
  52. Schema.org: FAQPage type
  53. Schema.org: HowTo type
  54. W3C: WCAG 2.2 quick reference
  55. FTC: CAN-SPAM Act compliance guide
  56. FCC: telemarketing and robocall rules (TCPA)
  57. FTC endorsement guides — reviews and testimonials
  58. FTC: rule on consumer reviews and testimonials
  59. HHS: HIPAA guidance on online tracking technologies
  60. New Jersey Courts: attorney advertising guidelines
  61. New Jersey DCA: construction codes and permits
  62. New Jersey Home Improvement Contractor registration
  63. New Jersey Division of Consumer Affairs
  64. TikTok for Business
  65. TikTok Creative Center
  66. TikTok Ads Help Center
  67. TikTok Community Guidelines
  68. TikTok Terms of Service
  69. TikTok Privacy Policy
  70. TikTok Safety Center
  71. TikTok Transparency Center
  72. TikTok Creator Portal
  73. TikTok Newsroom
  74. TikTok for Developers
  75. TikTok advertising solutions
  76. TikTok Creator Marketplace
  77. TikTok Business Center
  78. TikTok for Business blog
  79. TikTok Creative Center: top ads
  80. TikTok Branded Content policy
  81. TikTok Shop for sellers
  82. Instagram for Business
  83. Instagram for Creators
  84. Instagram Help Center
  85. About Instagram
  86. Meta Business Suite
  87. Meta Business Help Center
  88. Meta Transparency Center
  89. About Meta
  90. Meta: Instagram platform docs
  91. YouTube Creators
  92. YouTube Official Blog
  93. YouTube Shorts help
  94. How YouTube Works
  95. YouTube Studio
  96. LinkedIn Marketing Solutions
  97. LinkedIn Help
  98. Pinterest Business
  99. Pinterest Business Help
  100. Snapchat for Business
  101. X for Business
  102. Reddit communities
  103. Reddit for Business Help
  104. ASCAP
  105. BMI
  106. SESAC
  107. Global Music Rights
  108. PRS for Music (UK)
  109. PPL (UK)
  110. SOCAN (Canada)
  111. APRA AMCOS (Australia)
  112. GEMA (Germany)
  113. SACEM (France)
  114. SIAE (Italy)
  115. JASRAC (Japan)
  116. IFPI
  117. RIAA
  118. National Music Publishers Association
  119. Harry Fox Agency
  120. SoundExchange
  121. Music Reports
  122. Epidemic Sound
  123. Artlist
  124. Soundstripe
  125. PremiumBeat
  126. AudioJungle
  127. Free Music Archive
  128. Creative Commons
  129. Incompetech
  130. FTC: advertising and marketing
  131. FTC: disclosures 101
  132. FTC: endorsement guides
  133. FTC: consumer reviews rule
  134. FTC: advertising FAQs
  135. US Copyright Office
  136. US Copyright Office: DMCA
  137. US Copyright Office: music FAQ
  138. US Copyright Office: fair use FAQ
  139. USPTO: trademarks
  140. UK Advertising Standards Authority
  141. ACCC (Australia)
  142. Competition Bureau Canada
  143. GDPR overview
  144. California Consumer Privacy Act
  145. COPPA
  146. FTC: children’s privacy
  147. W3C Web Accessibility Initiative
  148. W3C: WCAG
  149. W3C: captions
  150. W3C: making audio and video accessible
  151. ADA.gov
  152. WebAIM
  153. Epilepsy Foundation
  154. Pew Research: internet and technology
  155. DataReportal
  156. US Census Bureau
  157. US Bureau of Labor Statistics
  158. Interactive Advertising Bureau
  159. Think with Google
  160. Google Trends
  161. Nielsen insights
  162. Schema.org: VideoObject
  163. Schema.org: SocialMediaPosting
  164. Schema.org: MusicRecording
  165. Schema.org: HowTo
  166. Schema.org: FAQPage
  167. Schema.org: Organization
  168. Google: video best practices
  169. Google: video structured data
  170. CapCut
  171. Adobe Premiere Rush
  172. DaVinci Resolve
  173. Canva
  174. Descript
  175. VEED
  176. Kapwing
  177. Otter.ai
  178. Later
  179. Buffer
  180. Hootsuite
  181. Sprout Social
  182. Google Analytics
  183. Google Search Console
  184. Google Analytics developer docs
  185. GA4: events and conversions
  186. Matomo
  187. Plausible Analytics
  188. Similarweb
  189. UK Information Commissioner’s Office
  190. Office of the Privacy Commissioner of Canada
  191. Australian OAIC
  192. European Data Protection Board
  193. EU data protection
  194. EU Digital Services Act
  195. Ofcom
  196. FCC
  197. AIGA
  198. Nielsen Norman Group
  199. Smashing Magazine
  200. web.dev
  201. MDN: web media
  202. MDN: the video element
  203. ISO 21001 (reference)
  204. Buma/Stemra (Netherlands)
  205. STIM (Sweden)
  206. Teosto (Finland)
  207. Koda (Denmark)
  208. TONO (Norway)
  209. IMRO (Ireland)
  210. SGAE (Spain)
  211. ZAiKS (Poland)
  212. KOMCA (South Korea)
  213. MCSC (China)
  214. CISAC
  215. World Intellectual Property Organization
  216. TikTok: creating videos
  217. TikTok: exploring videos
  218. TikTok: privacy settings
  219. TikTok: growing your audience
  220. TikTok Creator Academy
  221. TikTok Effect House
  222. TikTok for small business
  223. Instagram: Reels help
  224. YouTube: Shorts best practice
  225. How YouTube recommends
  226. Pinterest Predicts
  227. Snapchat for Business
  228. Hootsuite blog
  229. Social Media Examiner
  230. Marketing Week
  231. Adweek
  232. Manifesto for Agile Software Development
  233. Principles behind the Agile Manifesto
  234. The Scrum Guide
  235. NIST Secure Software Development Framework

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