Scrumban: And Other Essays on Kanban Systems for Lean Software Development [Brossura]

Scrumban in a small book by Corey Ladas self-published by lulu.com. The name is somewhat confusing since most of the book is about setting up a SW Kanban system and only a couple of pages are about scrumban (the hybrid between kanban and scrum).

Scrumban is an rather interesting book. I loved reading it and I think that it is an important contribution to software development. I say this even though I disagree with perhaps half of the book -- or at least consider them to be build upon shaky assumptions. Whether that is true or not, Corey delivers an interesting way of thinking about software development and a good basis for further discussion and improvement.

The book describes applying lean manufacturing techniques to software development. Unlike earlier lean material, it takes lean techniques and maps them to software on a very concrete level. The main technique taken from lean is the kanban technique for scheduling work. The book starts by describing "ideal" states of how software development should look like when mapping lean ideas to software. After that, it takes a couple of steps back and gradually builds up a kanban system by discussing one improvement to the system at the time. Halfway the book it describes how you can start applying kanban within your Scrum implementation and gradually improve it until its not scrum anymore, but kanban.

The end of the book discusses some more 'advanced' techniques like handling bugs, improving handovers, prioritizing backlogs and ... silver bullets :)

Corey tries to find a balance between traditional learnings and agile learnings. He tried to balance advantages of specialization with flexibility of generalization. He also tried to define a way of defining processes where Scrum basically just says "go and figure it out for yourself." This approach brings an interesting perspective to development processes.

So, what didn't I like? The book seems to assume that there is such a thing as a perfect workflow for software development. It even goes so far to suggest that this perfect workflow looks like the V-Model. If thats not bad enough yet, it suggests that XP is a "modern implementation of the V-Model." Here I start to feel somewhat uncomfortable. Why? A good team, IMHO, switches between the activities of software development constantly, within minutes. Work doesn't flow from one activity in another activity. Thats a workflow does doesn't fit in development, but has been artificially put over it. I would call it far from ideal, however, the V-Model workflow assumptions seem to run pretty deep in the book.

I loved the discussions on specialization and generalization. However, I'd stress domain-based specialization over activity-based specialization. Though, that doesn't seem to be covered much, except in a small part on scaling, but here it suggests to scale via component teams...

Another interesting thought that made me uncomfortable is the idea that there is such a thing as "in-control production" and special/common causes within that. To me, it feels like a manufacturing assumption within product development. Though Corey does cover these assumptions and makes great points about how to control variability, I'm not sure if it is a good thing to do.

All in all, the book gave me interesting thoughts and I might even be experimenting with some of them! I would NOT recommend reading the book when you are fairly new to agile development. The book assumes a pretty good understanding of certain concepts. However, if you want a different view on agile development and some different ideas, I would suggest reading this book. It will almost certainly contain some new ideas which makes the book worth reading.

Thanks to Corey for writing this small and interesting book.

Corey Ladas offers a gentle, conversational, and opinionated introduction to kanban and pull systems in Scrumban. As Bas Vodde notes the title's a little misleading - but if you come from a Scrum background and you're encountering these ideas for the first time, it makes a lot of sense, because Corey introduces a continuum of possible software process outlines, explaining each evolution and the reasons for it.

I enjoyed this book because it's clear, it takes a stand, and Corey clearly states what's his opinion based on his experience. I don't agree with all of it - in particular I have trouble with the feature-brigade ideas at the end - but for walking through the basics of kanban and pull systems, focused on real workflows and not abstract theory, you can't beat it. It's short, concise, and well targeted to anyone who's already familiar with the ideas of Scrum and XP. Anyone who's doing Scrum should come to understand these ideas, to have greater insight into how their process is working, even if they don't implement them. They're useful thinking tools. (You NEED background in agile software development to make sense of this book, though.)

One of the biggest risks with an approach like this - one you -need- to mitigate - is promoting silos and handoffs, after all the work other agile methods have done to break down the walls. Corey notes this in passing - that you want to map the workflow of the work but avoid siloing people into activity boxes - but I worry he doesn't make this clear enough.

Corey Ladas applies lean thinking to software development and, in general it is a good thought experiment. I like a lot what is in there and it helps me think through the things I need to say to my clients.

But I have two big "howevers".

First, why is every kanban and lean thinking book, this included, trying to compare software development to Toyota's manufacturing line? There isn't much overlap between software development and a manufacturing line except the unfortunate terms we use. Software development is all design, even coding is designing instructions for a compiler. The question shouldn't be how we do workflow in a manufacturing line but how do we do design and scale it. Fred Brooks recent book, the Design of Design, has important stuff on that.

Second is where do these nifty roughly equally sized work items for kanban come from? There is little to no discussion in this book (and many other software kanban books) where those wonderful work items come from. Most of my clients have these big feature ideas which take months to years to create with teams of 30 and I need a "feature" that is two weeks or less of work? Where did that come from? Who did that design?

Ladas does a fair job if you accept the two big "however" areas. This book is not for new people just trying to understand scrum and lean. It has a ton on insider references that can throw you off track if you are not familiar with them. Heck, I had to look up a few items and I am pretty well read. If you are a seasoned Scrum coach or aged methodologist, this book will give you good food for thought. Just keep the "howevers" in mind.