The Bus Factor
Being the only one who knows how the tenant works feels like job security. It’s the single biggest risk on your org chart — and it has your name on it.
tldr;
The “bus factor” is the number of people who’d have to get hit by a bus before your tenant is in serious trouble. For most HRIS teams, it’s one. It’s you.
Being indispensable feels like leverage. It’s actually a liability the org will eventually “manage” — and the thing being managed is sometimes you.
You did document. That’s not the problem. You wrote down the what. The why is still in your head.
Tribal knowledge isn’t expertise. It’s depreciating inventory. Treat it like inventory.
There’s a one-page Bus Factor Self-Audit at the bottom. Run it before your next vacation. Assuming you can take one.
Ten years ago when I started this gig, I took a week of PTO and brought my work laptop to Maine (Confession: 2026 will be the first year I don't. Please don't be like me).
Nobody asked me to. I just knew the annual comp process was going to throw an error somewhere around day three, and I was the only person alive who knew which condition rule was load-bearing and which one was decorative.
Day three. 2:14 on a Wednesday. The IM came in. I fixed it from a Adirondack chair on a deck at the lake in eleven minutes.
And I felt great about it.
That’s the part I want to talk about. Not the error. The fact that I felt great.
Your bus factor is one
Engineers have a name for this. The “bus factor.” It’s the number of people who’d have to get hit by a bus before a project is in real trouble.
Not fired. Not poached. Hit by a bus. The framing is grim on purpose, because the polite versions (“key-person dependency,” “knowledge concentration”) let you nod along without feeling it.
For many HRIS teams, the bus factor is one.
It’s you. You already know it’s you. And somewhere under the pride, you know that’s not a flex. It’s a liability with your name on it.
Indispensable and irreplaceable are not the same word
Here’s the trap. Being the only one who knows how the tenant works feels like security. If they can’t run payroll without me, they can’t get rid of me. Right?
Run that logic all the way forward.
An organization that can’t function without one specific person doesn’t think “we’re so lucky to have them.” Eventually it thinks “we have an unacceptable risk and we need to fix it.” And “fix it” rarely means a raise and a backup. It means reduce our dependence on that person.
Indispensability isn’t a moat. It’s a flag you’re waving that reads single point of failure, right here. And risk, given enough time, gets managed. Sometimes the thing being managed is you.
You did document. That’s not the problem.
I know what you’re going to say. I documented everything. You’ve got runbooks. A config workbook. That SharePoint nobody opens.
I believe you. And it won’t save you — because what you wrote down is the what (we started down this road last week, but let's expand).
“The Comp Eligibility rule excludes interns.” Great. That’s the what.
The why (why it excludes interns, which acquisition that rule survived, which VP will lose their mind if it changes, the fact that it’s quietly load-bearing for a downstream integration nobody remembers building) that’s not in the workbook.
That’s in your head. It’s been in there so long you don’t experience it as knowledge anymore. It’s just… how things are.
Month 14 is when the lights go out
I'm going to call him out again because I'm encroaching in his space. Seena Mojahedi has a name for the moment this becomes everyone’s problem: Month 14.
Your SI implements. They write the what documentation, because that’s what the SOW pays for. Then the SOW ends. For about a year, muscle memory carries the team. Then, somewhere around month fourteen, something changes that nobody internal has the why for, and there’s no consultant left to ask.
That’s the bus factor going off without anyone getting hit by a bus. The knowledge didn’t leave on a stretcher. It just left.
Tribal knowledge is a depreciating asset
Here’s the reframe that actually changes behavior.
Stop thinking of the knowledge in your head as expertise. Start thinking of it as inventory. Specifically, depreciating inventory. It loses value every time someone who shared it leaves, every time a process changes and the reason gets fuzzier, every release that buries the original logic one layer deeper.
You wouldn’t run a warehouse without knowing what’s on the shelves. You’re running the most important system in the company on an inventory exactly one person can see (and that person is tired and wants to take a real vacation).
The fix isn’t “write more documentation.” You’ll never out-document a system this complex, and a wiki nobody reads is just guilt with a URL.
The fix is to find out where your bus factor is actually one (which specific processes, which specific rules, which specific integrations) and start there. Not all forty things. The three or four that would genuinely take the org down.
So run the audit
I built a thing. It’s a one-page Bus Factor Self-Audit: a short, slightly uncomfortable set of questions you run against your own tenant to find the spots where the honest answer to “who else knows this?” is nobody.
It won’t fix your documentation. It’ll do something more useful: it’ll show you the handful of places where you’re the single point of failure, so you can stop pretending the other forty matter equally and go fix the ones that’ll actually hurt.
Alrighty, link is here. It's a Google drive link, so I'm guessing Google's going to want you to login first. Fill out the audit. Fix the holes. Then take the vacation. Leave the laptop.
I’m still working on that part too. Let's hope 2026 is the year for all of us.
— Mike
Director HR Tech | Recovering Single Point of Failure
P.S. I told Justin I was writing about what happens when the only person who knows how something works disappears. He thought about it and said, “you mean like when you’re the only one who knows the Wi-Fi password and you go to bed?”
Yeah, buddy. Exactly like that. Except the Wi-Fi password runs TA Tech for a couple hundred thousand people, and it can’t go to bed.
The Department of First Things First. For the people who do the work.