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User Stories
• Instead of Use Cases, Agile project owners do "user stories"
– Who (user role) – Is this a customer, employee, admin, etc.?
– What (goal) – What functionality must be achieved/developed?
– Why (reason) – Why does user want to accomplish this goal?
As a [user role], I want to [goal], so I can [reason].
• Example:
– "As a user, I want to log in, so I can access subscriber content."
• story points: Rating of effort needed to implement this story
– common scales: 1-10, shirt sizes (XS, S, M, L, XL), etc.](https://image.slidesharecdn.com/24-scrum-230421083145-9fef4161/85/Scrum-and-Agile-Software-Development-15-320.jpg)
Scrum and Agile Software Development
- 1. CSE 403 Lecture 24 Scrum and Agile Software Development Reading: Scrum Primer, by Deemer/Benefield/Larman/Vodde slides created by Marty Stepp http://www.cs.washington.edu/403/
- 2. 2 What is Scrum? • Scrum: – Is an agile, lightweight process – Can manage and control software and product development – Uses iterative, incremental practices – Has a simple implementation – Increases productivity – Reduces time to benefits – Embraces adaptive, empirical systems development – Is not restricted to software development projects – Embraces the opposite of the waterfall approach… It’s about common sense
- 3. 3 Scrum Origins • Jeff Sutherland – Initial scrums at Easel Corp in 1993 – IDX and 500+ people doing Scrum • Ken Schwaber – ADM – Scrum presented at OOPSLA 96 with Sutherland – Author of three books on Scrum • Mike Beedle – Scrum patterns in PLOPD4 • Ken Schwaber and Mike Cohn – Co-founded Scrum Alliance in 2002, initially within Agile Alliance
- 4. 4 Agile Manifesto Process and tools Individuals and interactions over Following a plan Responding to change over Source: www.agilemanifesto.org Comprehensive documentation Working software over Contract negotiation Customer collaboration over
- 5. 5 Project Noise Level Simple Complex Anarchy Technology Requirements Far from Agreement Close to Agreement Close to Certainty Far from Certainty Source: Strategic Management and Organizational Dynamics by Ralph Stacey in Agile Software Development with Scrum by Ken Schwaber and Mike Beedle.
- 6. 6 Scrum at a Glance 30 days 24 hours Product Backlog As prioritized by Product Owner Sprint Backlog Backlog tasks expanded by team Potentially Shippable Product Increment Daily Scrum Meeting Source: Adapted from Agile Software Development with Scrum by Ken Schwaber and Mike Beedle.
- 7. 7 Sequential vs. Overlap Rather than doing all of one thing at a time... ...Scrum teams do a little of everything all the time Requirements Design Code Test
- 8. 8 Scrum Framework •Product owner •Scrum Master •Team Roles •Sprint planning •Sprint review •Sprint retrospective •Daily scrum meeting Ceremonies •Product backlog •Sprint backlog •Burndown charts Artifacts
- 9. 9 Scrum Roles – Product Owner • Possibly a Product Manager or Project Sponsor • Decides features, release date, prioritization, $$$ – Scrum Master • Typically a Project Manager or Team Leader • Responsible for enacting Scrum values and practices • Remove impediments / politics, keeps everyone productive – Project Team • 5-10 members; Teams are self-organizing • Cross-functional: QA, Programmers, UI Designers, etc. • Membership should change only between sprints
- 10. 10 "Pigs" and "Chickens" • Pig: Team member committed to success of project • Chicken: Not a pig; interested but not committed A pig and a chicken are walking down a road. The chicken looks at the pig and says, "Hey, why don't we open a restaurant?" The pig looks back at the chicken and says, "Good idea, what do you want to call it?" The chicken thinks about it and says, "Why don't we call it 'Ham and Eggs'?" "I don't think so," says the pig, "I'd be committed but you'd only be involved."
- 11. 11 Sprint Planning Mtg. Sprint planning meeting Sprint prioritization • Analyze/evaluate product backlog • Select sprint goal Sprint planning • Decide how to achieve sprint goal (design) • Create sprint backlog (tasks) from product backlog items (user stories / features) • Estimate sprint backlog in hours Sprint goal Sprint backlog Business conditions Team capacity Product backlog Technology Current product
- 12. 12 Daily Scrum Meeting • Parameters – Daily, ~15 minutes, Stand-up – Anyone late pays a $1 fee • Not for problem solving – Whole world is invited – Only team members, Scrum Master, product owner, can talk – Helps avoid other unnecessary meetings • Three questions answered by each team member: 1. What did you do yesterday? 2. What will you do today? 3. What obstacles are in your way?
- 13. 13 Scrum's Artifacts • Scrum has remarkably few artifacts – Product Backlog – Sprint Backlog – Burndown Charts • Can be managed using just an Excel spreadsheet – More advanced / complicated tools exist: • Expensive • Web-based – no good for Scrum Master/project manager who travels • Still under development
- 14. 14 Product Backlog • The requirements • A list of all desired work on project • Ideally expressed as a list of user stories along with "story points", such that each item has value to users or customers of the product • Prioritized by the product owner • Reprioritized at start of each sprint This is the product backlog
- 15. 15 User Stories • Instead of Use Cases, Agile project owners do "user stories" – Who (user role) – Is this a customer, employee, admin, etc.? – What (goal) – What functionality must be achieved/developed? – Why (reason) – Why does user want to accomplish this goal? As a [user role], I want to [goal], so I can [reason]. • Example: – "As a user, I want to log in, so I can access subscriber content." • story points: Rating of effort needed to implement this story – common scales: 1-10, shirt sizes (XS, S, M, L, XL), etc.
- 16. 16 Sample Product Backlog Backlog item Estimate Allow a guest to make a reservation 3 (story points) As a guest, I want to cancel a reservation. 5 As a guest, I want to change the dates of a reservation. 3 As a hotel employee, I can run RevPAR reports (revenue- per-available-room) 8 Improve exception handling 8 ... 30 ... 50
- 18. 18 Sprint Backlog • Individuals sign up for work of their own choosing – Work is never assigned • Estimated work remaining is updated daily • Any team member can add, delete change sprint backlog • Work for the sprint emerges • If work is unclear, define a sprint backlog item with a larger amount of time and break it down later • Update work remaining as more becomes known
- 19. 19 Sample Sprint backlog Tasks Code the user interface Code the middle tier Test the middle tier Write online help Write the Foo class Mon 8 16 8 12 8 Tue 4 12 16 8 Wed Thu 4 11 8 4 Fri 8 8 Add error logging 8 10 16 8 8
- 21. 21 Sprint Burndown Chart • A display of what work has been completed and what is left to complete – one for each developer or work item – updated every day – (make best guess about hours/points completed each day) • variation: Release burndown chart – shows overall progress – updated at end of each sprint
- 23. 23 Hours 40 30 20 10 0 Mon Tue Wed Thu Fri Tasks Code the user interface Code the middle tier Test the middle tier Write online help Mon 8 16 8 12 Tue Wed Thu Fri 4 12 16 7 11 8 10 16 8 50
- 24. 24 Burndown Example 1 No work being performed Sprint 1 Burndown 0 10 20 30 40 50 60 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Days in Sprint Hours remaining
- 25. 25 Burndown Example 2 Work being performed, but not fast enough Sprint 1 Burndown 40 41 42 43 44 45 46 47 48 49 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Days in Sprint Hours remaining
- 26. 26 Burndown Example 3 Work being performed, but too fast! Sprint 1 Burndown 0 10 20 30 40 50 60 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Days in Sprint Hours remaining
- 27. 27 The Sprint Review • Team presents what it accomplished during the sprint • Typically takes the form of a demo of new features or underlying architecture • Informal – 2-hour prep time rule – No slides • Whole team participates • Invite the world
- 28. 28 Scalability • Typical individual team is 7 ± 2 people – Scalability comes from teams of teams • Factors in scaling – Type of application – Team size – Team dispersion – Project duration • Scrum has been used on multiple 500+ person projects
- 29. 29 Scaling: Scrum of Scrums
- 30. 30 Scrum vs. Other Models
- 31. 31 Credits, References – Mike Cohn, Mountain Goat Software www.mountaingoatsoftware.com – Scrum and The Enterprise by Ken Schwaber – Succeeding with Agile by Mike Cohn – Agile Software Development Ecosystems by Jim Highsmith – Agile Software Development with Scrum by K. Schwaber and M. Beedle – User Stories Applied for Agile Software Development by Mike Cohn – www.agilescrum.com/ – www.objectmentor.com – jeffsutherland.com/ – www.controlchaos.com/scrumwp.htm – agilealliance.com/articles/articles/InventingScrum.pdf