This is my summary of Henrik Kniberg’s “Kanban and Scrum – making the most of both”, a session I attended at ScanDevConf 2010. Please understand that, except for the notes at the top and bottom, this post reflects the opinions of the speaker, not me.

A supershort summary of Scrum:

• Split your team into small parts
• Split your product into small parts
• Split your time into small parts

… i.e. instead of a large team working on a large product for a long time, you have small teams working on small pieces of the product for short periods of time.

Kanban is:

• a signalling system
• with visible indicators
• that are limited in number.

Kanban in software development includes:

• visualizing the workflow (with columns on a whiteboard)
• visualizing the stuff in workflow
• limiting work in progress (WIP)
• measuring and optimizing flow
• explicitly defining your policies – the definition of done, WIP limits etc

How do the two differ?

• Scrum has more rules than kanban. On a scale from prescriptive to adaptive, the order would be
  RUP > XP > Scrum > Kanban > do whatever works.
• Scrum defines roles while Kanban doesn’t. In practice they might look the same.
• Both are empirical and measure things (velocity, lead time, quality etc). Kanban gives you more knobs to twiddle to change the outcome.
• Scrum has one cycle: planning and committing, releasing, and retrospectives, all three are done on the same cycle. Kanban does not tie these together; you could have a different cycle for each one.
• In Scrum, items must fit within a sprint. Kanban allows long-running tasks, limited only by WIP limits.
• Both limit WIP. Scrum limits by velocity, per time; Kanban limits by column in the workflow.
• Scrum discourages mid-sprint change: “We want to work in peace and quiet for a few weeks”. In Kanban, you just need to wait for a slot to become available.
• In Scrum, the board is reset between sprints. In Kanban the board has a long life. Scrum gives you closure and a feeling of success, but also some waste.
• Scrum prescribes one team per board, cross-functional. Kanban is more permissive of specialist teams.
• Scrum prescribes estimation and calculating velocity. In Kanban both are optional.

For more information, read the free PDF minibook.

My opinion: Well-structured and informative. I’d been curious about Kanban, wondering if it might be worth trying instead of Scrum (which we use now). After this presentation I have a good grip on the differences between the two and know that Scrum suits our needs better.

Some fresh bookmarks from delicious.com

• NY Times: Unshaven Women – Free Spirits or Just Unkempt? – Many women believe shaving is part of good grooming. Others say, go ahead and break the rules. (Note: read the comments section!)
• The Economist: Defining what makes a country – UN membership? Diplomatic recognition? Issuing passports?
• Helium – Going, Going, Gone – The second most common element in the universe is increasingly rare on Earth—except, for now, in America.
• Machine Knits Socks by the Yard – Video demonstration of an antique (75 years) sock-knitting machine that turns out socks by the yard. Socks are made pretty much the same way today.
• YouTube – Making of the natural gas commercial –
• YouTube – Knitted commercial for natural gas –

Keeping me busy right now:

• Preparing for the planned refurbishment of our house. The discussions with the architect are more or less finished. Next steps: seek planning permission, find a builder, plan bathroom.
• Preparing for our upcoming vacation. This is our chance: Ingrid is (hopefully) old enough for a real vacation, and Baby 2 is not yet a hindrance. We’re going for a week in Beijing.
• Planning for this summer’s gardening activities. I’m thinking tomatoes, peas and herbs for the kitchen garden.

This weekend I sent Eric and Ingrid out to have fun (they went swimming, and to Junibacken) so I could finally clear all the papers off my desk and do a GTD (Getting Things Done) weekly review. It had been way longer than a week since last time and I felt like I had lots of uncaptured tasks floating around.

Well, now both the projects and next actions have been captured, and I have them all under control. The flip side is that I now know exactly how much stuff there is that I should be doing instead of spending time in front of the computer. The lists are shockingly long. My list of next actions, which I’ve previously mostly managed to fit onto Post-Its on one A4 page, now cover the best part of three pages.

The flip side of that, in turn, is that I feel challenged. There is nothing like a bit of pressure to get me moving. Time to get those lists down to size again!

While there are still patches of snow here and there in the garden (and a huge heap of it on the north side, where Eric dumped the snow from the roof) the crocuses are already blooming, the scillas are well underway, and in the warmest and sunniest spot, I spotted a hyacinth blossom.

The birds are ignoring our feeding table so I took it down today. I guess there are enough insects around for them. The tits and sparrows who were hanging around all winter now rarely show themselves. Instead the wood pigeons and thrushes are back from wherever they spent the winter.

And this afternoon I even noticed the year’s first butterfly. (On the neighbours’ roof.)