What's your bus factor?

My wife and I had our second child just under three weeks ago, and as I'm slowly beginning to find my equilibrium in the midst of my parental leave, I find myself contemplating my personal bus factor.

The bus factor is a tongue-in-cheek name for a measurement of a project or organization's level of robustness. The proposition is this: let's say that some critical people in your organization are out to lunch one day, and while crossing the street, they get run over by a bus. The bus factor is the minimum number of people who, if they go under that bus, will result in the project or organization being badly disrupted. It's a wonderful and horrible thought experiment that asks us to face the question: life happens---whether it be a bus or a baby, marriage or divorce, cancer or a long overdue vacation---and how does that affect the world of work?

Obviously, as an organization you don't want a low bus factor. If your project has a magic guru without which all is lost, then your bus factor is 1 and sooner or later all will be lost. So from the perspective of resilience, a higher bus factor is always better.

As an employee, however, a high bus factor is actually a very bad sign for your value to the organization. If your organization has (or thinks they have) lots of people just like you, then they probably won't be valuing you as much as you would like them to. As a researcher, my value is ultimately in my expertise and my ability to deploy that in ways few others can, so my bus factor had better be fairly low. So it would appear that from the perspective of the individual employee, a lower bus factor is always better.

When your bus factor is too low, however, that's bad for work-life balance. If you're critical path on everything you do, then the ups and downs of projects can't be shared with others. Every crisis is your crisis, and if you take time out then things break and you let everybody down. At its worst, your bus factor is effectively less than one and you're always doing overtime just to stay afloat.

So, what's your bus factor?

In my own personal transition over the past year and a half, as we've grown the synthetic biology team at BBN while still continuing to execute on projects that started well before, my bus factor has definitely been under one at times. Preparing for paternity leave, however, became a very interesting exercise in evaluating how things had changed and where I needed to rethink how I had things organized at work. I started well ahead of time, listing out all of my different responsibilities and seeing what were the truly critical things that needed me to do them before my gap, then working with colleagues to plan out how to cross the time of my absence. Since you never know when a baby will come, I started warning people about my likely disappearance weeks ahead of time (and there are wonderful labor prediction tools now available online to make it quantitative!). My bus factor in prediction seems to be about 1.5, meaning some things will break if I am gone too long, but my team can probably run for quite a while without me, given our preparations and the competence of the people that I collaborate with.

And now I'm gone. I've got a lovely baby girl, an older daughter who seems to be adapting well, and our sleep schedules are as unpredictable and in flux as any parents of a newborn might expect. I've been quite solidly off my email and not taking calls. I'm grateful for the privilege to have this time off and spend these early days at home, and think it's a tragedy that here in America so many who work are unable to take such time. Babies and parents both deserve better, and our economy could most certainly afford it if we had the will as a society.

When I come back, I will find out how right or wrong we were about my bus factor and our preparations. Maybe at this very moment a project is going down in flames and I will have to deal with terrible things in the moment when I first connect and read what I've been missing out on. But I hope not, and am grateful for the professional community that has let me continue to try to walk this work-life tightrope as I balance.