In an effort to better understand the challenges facing the ops team of a particular project here at $DayJob, a project manager asked this question:
How many users per [sysadmin] can our system support?
The poor lead sysadmin on that side of the house swiveled her chair over and said to me, "there is no answer to this question!" And we had a short but spirited discussion about the various ratios to admin staff at the places we've been. Per-user is useless, we agreed. Machine/Instance count per admin? Slightly better. But even then. Between us we compiled a short list of places we've been and places we've read about.
- Company A: 1000:1 And most of that 1 FTE was parts-monkey to keep the install-base running. The engineer to system ratio was closer to 10K:1. User count: global internet
- Company B: 200:1 Which was desperately understaffed, as the ops team was frantically trying to keep up with a runaway application and a physical plant that was rotting under the load. User count: most of the US.
- Company C: 150:1 Which was just right! User count: none, it was a being developed product.
- Company D: 60:1 And the admin was part-time because there wasn't enough work. User count: 200
- Company E: 40:1 Largely because 25-30 of those 40 systems were one-offs. It was a busy team. Monocultures are for wimps. User count: 20K.
This chart was used to explain to the project manager in question the "it depends" nature of admin staffing levels, and you can't rely on industry norms to determine the target we should be hitting. Everyone wants to be like Company A. Almost no one gets there.
What are the ratios you've worked with? Let me know @sysadm1138