Agile vs Iterative vs Waterfall models
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The document compares Agile, Iterative, and Waterfall methodologies in software development, detailing their phases, quality control, risk management, and project management practices. It emphasizes the differences in planning, execution, and completion processes, highlighting Agile's focus on continuous improvement and flexibility. The text uses analogies from cricket to illustrate the varying strategies of these methodologies, such as the phased nature of Waterfall versus Agile's dynamic and iterative approach.
Agile vs Iterative vs Waterfall models
- 1. Agile vs Iterative vs Waterfall Bollapragada. Venkata. Marraju [email protected] [email protected] https://in.linkedin.com/in/marraju
- 2. WATERFALL Model A D ANALYSIS DESIGN CODING BUG FIXING TESTING C Test Initiation Waterfall model Phase by Phase : Analysis > Design > Coding, >Testing and delivery of whole functionality Project Time line 25% 50% 65% 100%
- 3. ITERATIVE Model 1Code 1 Test 2Code 2 Test 3Code 3 Test 1A 2A 3A 4A 5A 1D 2D 3D 4D 5D 4Code 4 Test 5Code 5 Test ANALYSIS DESIGN C O N S T R U C T I O N A D c T Iterative Model For a small set of functionality Analysis & Design will be completed first before proceeding to Coding & Testing within same iteration. Project Time line 25% 50% 75% 100%
- 4. 4 C D A T Agile- SCRUM Model 10% 21% 33% 45% 58% 70% 82% 90% 100% Project Time line SCRUM model Analysis, Design, Code, Testing and delivery of a small functional pieces in with short cycles (sprints) ADCT Wheel A – Analysis D – Design C – Code T – Test
- 5. 14 days Sprint Daily Standup C D A T 5 SCRUM - Sprint 14 days Sprint ADCT Wheel A – Analysis D – Design C – Code T – Test
- 6. 6 Process vs Project Triangle ADC A D C T A D C TT Schedule Schedule Schedule WATER FALL ITERATIVE AGILE - SCRUM Waterfall Iterative Agile Format Test Match: Strategic- Phase by Phase like Innings by Innings. Game for Specialists. Slow and Steady. One Day: Strategic approach – First10/Middle/Slog overs. Mix of Specialists and All-Rounders. Result oriented. T20: Lively , Dynamic, Full of Action. Game for All-Rounders. Changes with every over. Highly Result oriented
- 7. Agile vs Iterative vs Waterfall {Process} {Planning} {Execution} {Completion}
- 8. 8 Agile vs Iterative vs Waterfall – {Process} Waterfall Iterative (hybrid) Agile Quality Quality focus changes from Analysis > Design > Code > Test Quality focus shifts between Analysis/Design phase to Coding/Testing phase Quality focus on all aspects of SDLC at any given time. Quality Control Detection & fixing during system and regression testing at the last phase of project. Early detection & fixing in each iteration for new features. Followed by regression testing. Early detection & fixing in each sprint followed by stabilization. Continual Improvement (CA & PA) Lessons learned from previous release implemented in next release Lessons learned from previous Iteration implemented in next Iteration. Lessons learned from previous sprint implemented in next sprint Risk No Risk Identification. Firefighting during testing phase. Risk identification & mitigation in dev & test phase of each iteration. Early identification & mitigation in every sprint. Postmortem/ Retrospection After every release After every iteration/ milestone After every sprint in retrospection meeting Customer Feed back At the end of the project. At the end of every iteration At the end of every sprint 4 Less Agile More Agile
- 9. 9 Practice Waterfall Iterative (hybrid) Agile Goals Goals are defined for each phase by defining entry and exit criteria. Delivering artifacts by phase wise. Completion of analysis & design for a set of features by one team followed by completion of code & test by another team. Completing the feature/story in all aspects within a sprint. Delivering the shippable product. Definition of Ready Analysis and design should be completed for all stories before programming Analysis and design should be completed for a ‘set of stories’ before programming Stories that are not subjected to change, that can be completed (analysis to demo) within the sprint will be considered for the sprint. Scoping Product Owner (PO) decides project scope Project Manager (PM) decides scope for iteration in consultation with Product Owner Team decides the sprint scope as per the capacity availability & product backlog prioritization Agile vs Iterative vs Waterfall – {Planning} Less Agile More Agile
- 10. 10 Practice Waterfall Iterative (hybrid) Agile Effort Estimation PM provides estimates and get approval from PO for entire project. Project Manager (PM) provides the estimation for each iteration. Scrum Master facilitates and Team does the estimation. Story points can be reviewed and refined during sprint planning meeting. Scheduling Scheduled by phase wise milestones – Analysis, Design, Development and Testing Scheduled based on Iteration wise delivery commitments – Iternation#1, #2, #3, #4, etc., Scheduled based on velocity and Release backlog. Time boxed in short cycles of duration say 1wk, 2wks, or 3wks – Sprint#1,#2,#3,#4, etc., Plan Review Team need to stick to baseline project plan. Team need to stick to baseline iteration plan Team can review during mid sprint planning Agile vs Iterative vs Waterfall – {Planning} Less Agile More Agile
- 11. 11 Practice Waterfall Iterative (hybrid) Agile Phase silos or Role silos or Story silos Analysis and design will be completed for all stories before proceeding to coding and testing. Lag by phase. Within in the team, analysts & architects work on analysis & design of future stories and pass it to the remaining team to work on coding & testing of those stories. Lag by phase with overlap Team gets divided into mini teams and each min team focus on story completion in all aspects – analysis, design, development, test, doc, delivery. There is no lag. Resource Utilization Role specific. Resources restricted to the tasks that suits/matches their role only. Role switch over rarely seen. Resources extend only on need basis. Role switchover common. Everybody is ready to work on any task (analysis/design/dev/test) to complete the story. Ownership Ownership changes from role to role by phase to phase. Roles play key role. PM responsible for overall delivery. PM is responsible for getting the iteration completed. Entire team is responsible for story completion in all aspects – analysis, design, development, testing and demo. Task Assignment Project Manager do the feature/task assignment for entire project. PM influence the feature/task assignment for entire iteration. Team members are empowered to own the feature/tasks for every sprint Agile vs Iterative vs Waterfall – {Execution} Less Agile More Agile
- 12. 12 Practice Waterfall Iterative (hybrid) Agile Daily Standup Daily/Weekly Status reports. PM calls for the status meeting at scheduled intervals Daily/Weekly Status reports. PM calls for the status meeting at scheduled intervals. Scrum Master facilitates the daily standup meeting to update: • what we did?, • what we are going to do? • where we lag? Status Report Status report in prescribed template. More focus on Percentage done. Status report in prescribed template. More focus on Percentage done. Update on daily basis by logging hours spent & hours required to complete. Burndown/Burnup chart reflects the remaining hours required to complete Planned vs Actual Stick to baseline project plan Stick to baseline iteration plan Actual hours burnt vs hours required to complete Agile vs Iterative vs Waterfall – {Execution} Less Agile More Agile
- 13. 13 Practice Waterfall Iterative (hybrid) Agile Testing Resources Only Testers will identify, prepare, and execute the TCs. Only Testers will identify, prepare, and execute the TCs. Any one in the team identify, prepare and execute TCs. New Feature Testing TC preparation and execution starts after analysis, design and development phase. TC preparation and execution starts after analysis and design phase. TC preparation and execution starts in parallel with analysis and design and completes within same sprint. Regression Testing After the completion of first cycle system testing. Partial coverage within the iteration and full coverage in stabilization iteration. Full coverage within the sprint. Stabilization Phase NA. Full scale regression testing after the completion of development iterations. No feature development. Only defect fix. Performance, deployment, migration testing after the completion of development sprints. No feature development. Only defect fix. Agile vs Iterative vs Waterfall – {Execution} Less Agile More Agile
- 14. 14 Practice Waterfall Iterative (hybrid) Agile Definition of Done DOD for a story will be measured by phase wise delivery of artifacts (req. doc, design doc, test cases, code) which are validated, reviewed, approved, baseline and delivered at the end of respective phase. DOD will be measured by phase wise delivery of set of features - analysis & design in one phase and development & testing in followed phase with in same iteration. DOD for a story will be measured by its capability of demonstration and delivery to the external world. Story Closing Delivering/Publishing artifacts (DOD) phase by phase Closing analysis & design stories. Closing code & test stories. Closing the story based on demo feedback, test case results (90% pass) and defect status (no critical & high defects) Delivery Delivering artifacts phase wise and delivery of working software at end of the project. Delivering working software at the end of each Iteration. Demonstration and delivering working software at the end of every sprint. Agile vs Iterative vs Waterfall – {Completion} Less Agile More Agile