The short version
New leaders usually try to change a culture before they understand it. The first ninety days are for reading the system, not rewriting it.
Every leader who inherits a team inherits a working culture — a set of habits that already produce results, good and bad. The instinct is to install your own operating system in week one. The better move is to spend a quarter learning why the current one survived.
Days 1–30: read the system
Your only job in the first month is accurate description. Sit in the meetings you didn't design. Watch who talks, who defers, who gets interrupted, and what happens to a bad number when it surfaces.
- Which decisions actually get made in the meeting, and which get made afterward in private?
- Who does everyone check with informally before committing to something?
- What is the last thing that got escalated, and how did it go for the person who escalated it?
Days 31–60: ask better questions
One-on-ones in this window should be almost entirely diagnostic. Three questions do most of the work: what should we stop doing, what is harder here than it should be, and what would you fix if you had my job for a week?
Most inherited dysfunction is a rational response to an incentive nobody has changed yet.
Days 61–90: change two things, loudly
Pick one change that removes friction people already complain about, and one that signals your standard for how disagreement gets handled. Announce both, explain the reasoning, and put a review date on the calendar.
Two visible changes with clear reasoning buy you more credibility than ten quiet ones. They also tell the team something important: that decisions here come with reasons attached.
Related resource
Team Norms Template
A one-page template for writing down how your team meets, decides, and disagrees — then reviewing it every quarter.
Get the Team Norms Template