Saturday, March 28, 2009

A Kanban System for Software Engineering

At QCON London 2008, David Anderson gave a talk about Kanban. David starts by mentioning he had some failures in institutionalizing agile changes and failing to scale it to a significant size. He then had success with Kanban. Kanban system allows for focus on quality, reduces or limits work in progress, balances demand against throughput, prioritizes.

David then describes a case study at Microsoft where a team was at CMMI level 5 and producing high quality software however they had a huge backlog and items constantly delyed. David shows how implementing Kanban helped this team improve productivity by 200%.

Instead of having an agile transition plan and force a team to use a particular agile process, David now advocates starting from where you are now and create a culture that encourages people to improve, teach them lean principles, teach them about waste and bottlenecks, and then have the team figure out on how to get better.

David then covers another case study at Corbis and describes Kanban in more details. Kanban can work with specialist teams of analysts, developers, testers, QA, etc. However, it puts a limit on the amount of items that each team can process. There are no iterations in Kanban. It is more of a continues flow with a release every 2 weeks, but the release content is bound and published only 5 days prior. Items that take longer than 2 weeks are just not released. Prioritization meetings are held every week (inputs and outputs are not in sync in a cycle). Whenever there is an empty slot, an item from the backlog is added. Prioritization and competition for an empty slot eventually evolves into collaboration. No estimation is done on individual items, with the effort to estimate turned back into increased productivity in analysis, coding, testing, etc. The Kanban white board gives visibility into process issues (transaction cost of releases, transfer though stages, bottlenecks, ragged flow). Daily stand up helps eliminate impediments affecting productivity and lead time. Kanban also allows for scaling standup meetings. Large teams can go through tickets on the board and ask if anyone knows of something impeding the progress of the ticket.

David summarizes that the Kanban method enabled:

1. Culture Change: trust, empowerment, collaborative team working and focused on quality.

2. Policy Changes: No estimating, late binding release scope, late binding prioritization

3. Regular delivery cadence: Releases become routine.

4. Cross functional collaboration

5. Self regulating process robust to gaming and abuse

6. Continuous improvement: Increase throughput, high quality, process continually evolving, kanban limits empirically adjusted.

7. Little Management Overhead: Little to no involvement in day to day

This presentation is available on InfoQ at