Dunbar, Scaling Agility and Value Stream Containers (VSC)
So many choices on the menu
You can’t shake a sharpie pen these days without hitting someone who has an opinion (or a sales pitch) about the very best way to “Scale Agile.”
You have a veritable smorgasbord of options, including but not limited to:
- SAFe – Scaled Agile Framework®
- LeSS – Large Scale Scrum
- DAD – Disciplined Agile Delivery
- GROWS – The GROWS™ Method
- SPS / Nexus – Scaled Professional Scrum / Nexus™ Framework
In spite of all of the nuanced discussions, debates and frequent diatribes, scaling agile is about one thing: getting large groups of teams to deliver value in an organized fashion while maintaining empathy, rapport, trust, safety, and ownership across the enterprise.
While doing some recent reading about scaling, I came across an article on SAFe that explored the “release train” and its functional upper limits of size. At about 150 people the post recommend that an additional release train be established. The article provided my first exposure to the concept of Dunbar’s Number.
For those like me that are new to concept:
“Dunbar’s Number is suggested cognitive limit to the number of people with whom one person can maintain stable social relationships. These are relationships in which an individual knows who each person is and how each person relates to every other person.” https://en.wikipedia.org/wiki/Dunbar%27s_number
In the 1990’s Anthropologist Robin Dunbar proposed the number is somewhere between 100 and 250, with a commonly used value of 150 people. His research, his theory, hence he gets to call 150 “Dunbar’s Number.”
Why do we care? Well, Dunbar theorized that “this limit is a direct function of relative neocortex size, and that this in turn limits group size … the limit imposed by neocortical processing capacity is simply on the number of individuals with whom a stable inter-personal relationship can be maintained.” Or in other words, our brains are only so big.
In the context of teamwork like software development, being able to have a stable social relationship with all the individuals on a team provides the benefits of being able to build and maintain empathy, rapport, trust, safety, and ownership.
I was able to experience this feeling while working with a client that had a collocated team of 120 developers. It truly was like a large family. While I moved on to another assignment, I recently returned to visit this client. Showing up on the team floor was like walking into Cheers! It honestly felt like I had never left.
Gore must have talked to Dunbar
Once I started reading more about Dunbar’s Number it brought back a memory of a random(?) conversation I had with a gentleman that worked at W.L. Gore. I am not sure how our conversation got to the topic but he was explaining how they handle organization of divisions within the company. He explained that Gore allows a division or a factory unit to grow to about 150 people. Once the headcount hits that number, they split the product line into separate divisions and add an additional location. And the growth cycle begins anew. Gore believes their approach helps keep continuity, trust, and common goals alive.
So when I look at the issue of scaling agility at an enterprise level, I see how the logic of Gore’s approach. It is Dunbar’s Number applied to organizational structure and culture.
Value Stream Containers
Bringing my thoughts back around to SAFe, or any other framework you choose, I propose the concept of Value Stream Containers (VSC). A single VSC will have a headcount limit of, you guessed it, Dunbar’s Number, or about 150 people.
Within a single VSC, all members will have the opportunity for stable relationships. Along with that they will have a common understanding of what, why and who they are servicing. Each VSC will be aligned to internal or external business opportunities, projects, or products. (Call them what you like, that discussion is beyond the scope of this article.)
Break the VSC down internally into two-pizza scrum squads (the number of mouths you can feed with two large pizzas, 7±2) if you like, but any time a VSC grows larger than 150, it is splitting time. Actually, it might be a good practice to consider splitski at about the 100 person mark. Doing so will provide the headroom for an additional capacity of 50 people per VSC over time, prolonging the lifespan of existing and new cognitive connections.
An Initial Glimpse
This is just a glimpse into my thoughts on Value Stream Containers. Is the magic number really 150? Who knows. You might think I’m full of primate excrement because you are an above-average Facebook user with more than 338 friends, or a LinkedIn master with 500+ connections.
Using Dunbar’s math you’d tell me none of these networks of yours would be stable. But I bet you’ve already created VSC’s, if not via groups, at least in your neocortex, creating a shared identity with people: family, high school buddies, collecting by shared interests, job titles, places worked together. And each of these groups behave within a shared set of agreements and expectations, at a sustainable pace that’s appropriate for that VSC.
If you could count your connections based on those buckets what would you find? For those that you feel a strong sense of connection, empathy and rapport I’m betting on some magic.
I would love to hear your feedback on my VSC concept.