The org chart tells you reporting lines, not who decides

Two structures, and only one of them is written down

An org chart answers exactly one question: who is formally accountable for whom. That is a real question, and the answer matters at review time, when a budget is signed, and when something goes wrong badly enough that a name has to be attached to it. What the chart doesn’t tell you is how a decision gets made on an ordinary Tuesday. New joiners memorise it anyway, because it is the only document available, and then spend months puzzled that the person at the top of the box had no idea a change was happening.

The second structure is the one that decides things. It is built out of habit, history, personal trust and a small number of people whose objection reliably stops work. Nobody publishes it because nobody inside experiences it as a structure at all; from within it just feels like knowing who to talk to. Learning it is not politics in the grubby sense of the word. It is the difference between a proposal that lands and an identical proposal that quietly dies in somebody’s inbox.

Decisions leave traces, and you can follow them backwards

The fastest way to see the real structure is to take one decision that was made in the months before you arrived and reconstruct how it happened. Pick something concrete — a tool that was adopted, a process that changed, a project that was cancelled. Then ask three people who were around at the time how it came about. You aren’t looking for the official account. You are looking for the point in each retelling where somebody says that a particular person was fine with it.

Two categories emerge almost immediately. There are people who were consulted before the decision, and people who were informed afterwards. That split is the actual map, and it frequently cuts across seniority in ways the chart would never predict. Someone two levels up can turn out to be reliably in the second group, which tells you something important about what their approval is worth. Note also that the same person sits in different groups for different subjects, because influence is usually domain-specific rather than general.

Authority and influence come apart in predictable places

A few roles accumulate informal power almost regardless of grade. The person who has been there longest and remembers why an odd rule exists. The one who maintains a system everybody depends on and nobody else understands. Whoever controls a calendar, a budget line or a queue. These people rarely have veto power written down anywhere, but they have something functionally similar, which is the ability to make a thing take six weeks instead of two.

There is also a difference between being able to approve something and being able to block it, and blocking is far more widely distributed. In most organisations a surprising number of people can stop work, and very few can start it. That asymmetry explains a lot of otherwise baffling behaviour, including why experienced colleagues spend so much apparent effort on conversations that produce no decision. They aren’t stalling. They are clearing objections in advance, one person at a time, so the meeting where the decision is formally taken is a formality.

The calendar tells you more than the handbook

Recurring meetings are a fossil record. Each one was created because somebody, at some point, needed a regular forum for something, and looking at which ones have survived tells you what the organisation genuinely worries about. A weekly meeting that senior people never miss is a statement of priority, whatever the strategy document says.

Look, too, for the small meeting that happens shortly before the large one. That pattern is extremely common and it is where most real decisions get settled. The larger session then serves to communicate, to give people a chance to raise anything genuinely unexpected, and to create a record. If you only ever attend the large meeting, you will consistently misunderstand where things were decided and wrongly conclude that decisions here are made in the room.

Some of what you find is not structure but dysfunction

Be honest about the difference. A shadow structure that exists because a few experienced people have earned trust is healthy, if slightly opaque. A structure that exists because one person hoards information and enjoys being asked is a failure of management, and describing it neutrally as how things work here does nobody any favours.

The tell is whether the informal route is teachable. If colleagues will explain why you should check with a particular person, and the reason is a real one, the place is merely undocumented. If nobody will explain, or the rules change depending on who is asking, you are looking at something worse, and no amount of skilful navigation fixes it.

What to do with the map once you have it

Mostly, use it to sequence conversations rather than to work angles. If you have a suggestion, knowing that a particular colleague will be uneasy about it means you can go and ask them what they would be worried about before you write anything down. That is not manoeuvring; it is the same courtesy you would want extended to you, and it produces better proposals because their objection is usually well founded.

Keep the map private and keep it provisional. It changes with every reorganisation and every new manager, and a confident model of who matters is a liability once it is a year out of date. You will get it wrong repeatedly at first, which is fine: the cost of a misdirected question is small, and the redirection corrects the map.