Agile, Estimation and Projects

Transcription

1 Agile, Estimation and Projects Where do budgets come from? Slide June 2011 Daryn Holmes, Karen Paludan, Keith Braithwaite Economic Activity Building software for a living is primarily an economic activity Only secondarily (at best) technical Sorry., Keith Braithwaite 28. June 2011 Slide 2 1

2 Getting Started How Agile Projects Begin Slide June 2011 Daryn Holmes, Karen Paludan, Keith Braithwaite Projects According to the PMBOK, a project is: A temporary endeavor undertaken to create a unique product, service or result Temporary A starting point An ending point Create a A definite goal for the project In practice, projects also have a business case and a budget 28. June 2011 Slide 4 2

3 Agile Projects in Theory The Product Owner defines an initial Product Backlog, a release plan, funding, etc. The Team along with the Scrum Master, and the Product Owner decide an iteration length (and stick to it) Plan the first iteration: define the Sprint Backlog, the Sprint Goal, the tasks Start! 28. June 2011 Slide 5 No Chance! Outside of a Lean startup or similar that will never fly Agile/Scrum/etc has a good story for the steady state Not so much for getting a project started 28. June 2011 Slide 6 3

4 In Reality Inception phase Project goal Initial estimates Duration Staff Money Initial product backlog 28. June 2011 Slide 7 Budgeting: The Traditional Approach 1. Requirements Document 2. Work Breakdown Structure 3. Bottom-up estimation 4. Roll-up to project estimate 5. contingency 28. June 2011 Slide 8 4

5 Work Breakdown Structure Most WBS for software development are invalid 100% principle Each parent node must be exactly 100% satisfied iff all its children are satisfied Mutually exclusive items Zero overlap between work items Outcomes not actions WBS items should not describe activities Very rare to be able to do this with software projects 28. June 2011 Slide 9 Cone of Uncertainty Initial estimate of 1 year: Actual between 3 months and 4 years Best case From McConnel Software Estimation 28. June 2011 Slide 10 5

6 Planning Fallacy In cognitive science, planning fallacy is the tendency for people and organizations to underestimate how long they will need to complete a task, even when they have past experience of similar tasks over-running Kahneman, Daniel; Tversky, Amos (1979). Intuitive prediction: biases and corrective procedures 28. June 2011 Slide 11 Agile Estimation How Zuhlke prices projects Slide June 2011 Daryn Holmes, Karen Paludan, Keith Braithwaite 6

7 Agile Estimation The primary purpose of software estimation is not to predict a project s outcome; it is to determine whether a project s targets are realistic enough to allow the project to be controlled to meet them McConnell, Software Estimation 28. June 2011 Slide 13 Estimation and Commitment Negotiate commitments not estimates An estimate is not a prediction An estimate is a guide An estimate reflects uncertainty 28. June 2011 Slide 14 7

8 Estimating an Agile Project No BRD, no Technical Specification, but A vision for the project, and epics 28. June 2011 Slide 15 User Story Mapping By arranging activity and task-centric story cards spatially, we can tell bigger stories Tell a big story (epic) by starting with the activities the product will be used for time Arrange activities left to right in the order you d explain them to someone when asked the question: What do people do with this system? 28. June 2011 Slide

9 Add Task-Centric Stories to Refine Activities Add task-centric stories in under each activity in chronological order left to right. time If you were to explain to someone what a person typically does in this activity, arrange tasks in the order you d tell the story 28. June 2011 Slide 17 Capture Parallelism and Alternatives Overlap user tasks vertically if a user may do one of several tasks at approximately the same time. time If in telling the story I say the systems user typically does this or this or this, and then does that, or s signal a stacking vertically, and then s signal stepping horizontally. 28. June 2011 Slide 18 9

10 Reading the Story Map The map of stories shows both story decomposition and a typical flow of use across the entire system Simply reading the activities, or large stories, across the top of the system helps us understand end-to-end use of the system time Below each activity, or large story are the child stories that make it up 28. June 2011 Slide 19 Two important anatomical features The backbone of the application is the abstract list of essential activities the application supports The walking skeleton is the actual software we build that supports the least number of necessary tasks across the full span of functionality necessity The backbone The walking skeleton time 28. June 2011 Slide 20 10

11 Broadband Delphi Slide June 2011 Scrum Master Course Daryn Holmes, Karen Paludan Top Down Estimation Use Delphi to estimate the epics determine whether a project s targets are realistic enough ROI should exceed the planned investment by orders of magnitude Projects which require very accurate estimates to be viable are not viable 28. June 2011 Slide 22 11

12 Ranges Estimate as a rage: Minimum, expected, maximum Arbitrage precision for accuracy 28. June 2011 Slide 23 Story Map to Plan mandatory more necessary less necessary necessity time First Release 28. June 2011 Slide 24 12

13 Story Map to Plan mandatory more necessary less necessary necessity time First Sprint Second Sprint 28. June 2011 Slide 25 Release Cycle Sprint 1 Sprint 2... Sprint n... Sprint m... Release 1 Release 2... Each sprint should be releasable..but cost of deployment may be too high - User training, shipping cost, sys-admin time, etc Keep to release dates as far as possible - Teams work better with fixed iteration lengths - Adjust iteration content rather than move dates 28. June 2011 Slide 26 13

14 Revise Estimates and Projections Test (hours) Story (days) Sprint (weeks) Release Increasing frequency of feedback (months) Product (years) 28. June 2011 Slide 27 Essay What techniques exist for estimating the cost and duration of software development projects and what evidence is there for their effectiveness in helping project deliver on-budget and on-time?, Keith Braithwaite 28. June 2011 Slide 28 14

15 Questions? Slide June 2011 Daryn Holmes, Karen Paludan, Keith Braithwaite 15