This originally appeared on my old blog in February 2009.

There are, IMHO, some good reasons and some bad reasons to consider switching from Scrum to Kanban… or for considering Kanban over Scrum as a starting point for ‘going Agile’ (so to speak)…

‘Good’ reasons for considering Kanban are…

• Wanting/needing more visibility of specific development process constraints (bottlenecks) than Scrum gives you (Scrum shouts “there’s a problem!”, Kanban points at where the problem is)
• Kanban can avoid waste of stories not filling a Scrum sprint (although finishing ‘early’ can allow teams to make improvements they might not otherwise have afforded themselves)
• Kanban can focus teams on vertical stories from the outset whereas new Scrum teams seem to start with horizontal slicing.

‘Bad’ reasons to choose Kanban over Scrum are…

• Wanting to say you are “Agile” without really changing your development process
• Because using Scrum is exposing rigidity and brittleness of software that is the output of your development process and wanting to hide that behind Kanban words like cadence
• Hiding impact of speculative design behind Kanban work-items when it fails in Scrum because the work never seems to fit into a Sprint, spilling the story over multiple sprints

(by speculative designs I mean implementing architecture that is more than is necessary for current valued-work-item)

For a team that has legacy development practices, producing legacy code for which it simply isn’t realistic to do incremental and iterative development but wants gradual and continuous improvement… I think Kanban is perhaps a better place to start. Your first ‘work-item’ may take 3 months… but it’s an honest 3 months! The trick is to make continuous improvements to gradually increase the tempo of your delivery.

If a team needs to suffer the pain – that comes from seeing that no matter how hard you try you simply can’t fit the implementation of even the smallest feature into one month – before it realises it has a problem… Then maybe Scrum is the better place to start.

Whichever you choose, I hope you choose the right approach for you, for the right reasons 😉