October 20, 2003
ForUSE - Jeff Patton
Usage Centred design in Extreme programming and agile development environments
Raw Notes...
Agile software development isn't anything new. Books so far (since 1971) have discussed the psychology of teams and programmers within them.
- Scrum
- Peopleware
- Dynamic Systems Development Methodology
- Crystal Methodologies
- Feature Driven Development
- Adaptive Software
- Extreme Programming
Born of financial need to make things quicker... meeeting of 17 people at Snowbird, Utah, 2001 formed 'the Agile Alliance'. 4 core principles of the Agile Alliance.
- Individuals and Interactions over Processes and Tools (within the business)
- Working Software over Comprehensive Documentation
- Customer Collaboration over Contract Negotiation
- Responding to change over following a plan.
There are other additional statements are also important and can be found at The Agile Alliance website.
Agile, like UCD is an approach to a method, not a method itself. Releases are composed of Increments which deal with making features. Release Cycle: plan release, feature list, evaluate release. Increment Cycle: Plan increment, determine feature list, evaluate increment. Feature cycle: Design Feature, develop feature, evaluate feature.
Less emphasis on artifacts, up-front design but more on customers and end-user collaboration and emphasis on day to day collaboration within the development team. Incremental improvement resulting in WORKING and USABLE software. Feedback using iterations.
Interesting XP points. Simplicity in design, test driven development, collective ownership, coding standards, System Design Metaphors, Frequent small releases, Customer acceptance testing.
Injecting UCD into XP - Release: Reconcile Roles and Goals with tasks then features. Role and task determine feature priority. Role and Task information drive feature design. Use feature priority and cost to find scope cutting opportunities. Increment: Role and talks information determine bug criticality. Feature: Role and Task information Drive feature design. Test using use cases assuming a user role.
Understanding the Domain. Contextual design work, taking photos of your end users, hear from them and their managers and other stakeholders. All the team needs to be across the end users.
Tactile collaboration tools and techniques - all your typical post-it note jockey stuff. Food, and Kitchen timer is helpful. Means motive and opportunity (as a way to get people involved in collaborative working. Basically, make it easy for them to do so). Make it fun and quick paced.
Accuracy and Detail aren't the same thing. Focus should be on Accuracy to begin with. Detail can come later... [ this really suits my 'Cut but Cut' thoughts ]. A conversation is better than a document. A poster is better than a document (they're like radiators of information - nice metaphor!). Avoid literal UI renderings.
Must get Alistair Cockburn (Humans and Technology inc.) Book.
Use Focal roles and focal task cases to drive priority. Relax standards on the unimportant features. Special attention to quality on quality for focal roles and tasks.
Detailed design comes in where necessary... as in later on. Write essential use cases, build abstract UI prototypes, Render wireframe UI, Validate through testing.
Agile is great because it allows for the mistakes YOU WILL make. The penalties are less because of the iterative nature of the process.
There are problems, but they mainly come from team issues. People not wanting to change or being freaked out by being out of their comfort zone.
Collaboration plan - contract between customer and design/development team.
Jeff Patten