Symmetry shows in the joiners and leavers, not at the door.

Access control from any manufacturer degrades in the same place: the list. Not the equipment, which goes on working, but because people are added and never removed, because permissions are granted as a favour and never reviewed, and because nobody knows any more who authorised a supplier to open the warehouse. Two years on, the system opens fine and the list lies.

Symmetry is a high-end access platform —its own server, controllers on the wall, event logging, integration with video and intruder detection— and at the same time it is the home of a layer that tackles that problem head on: requesting access with approval from whoever is in charge of that zone, withdrawing it automatically when personnel marks somebody as a leaver, and forcing a review every so often of whether whoever has access to an area still needs it.

You find it where the record of who was allowed in has to stand up to scrutiny: public administration, energy, pharmaceuticals, banking, data centres, sites with a lot of contractors. Places where the awkward question is not whether the door holds, but who authorised that permission and when it was last reviewed.

A Windows server with a SQL database, administration clients and a web client for everyday work. Underneath it has its own line of controllers, with a distinctive architecture: a main unit with two-, four- or eight-door modules hanging off it on a bus, which lets you grow door by door and works out well in buildings where doors turn up three at a time. And it also talks to the most widely deployed controller family in the industry, which opens the door to installations that already exist.

Around it are the parts that are usually missing: visitor management with a register and pre-notification, its own video so you can see what happened at that door, credentials on the phone and support for high-security identity credentials, the kind that are not just read but verified against the card itself. That last point partly explains where it is deployed.

And the identity governance layer, which is what sets it apart: a person requests access to a zone, the manager of that zone approves or refuses, the system applies it and who authorised it is written down. When human resources marks somebody as a leaver, the access is withdrawn without anybody having to remember. And every so often the manager receives the list of who has access to their area and has to confirm it or cut it back.

That layer depends on two things that are not technical. The first is that the personnel system is the truth: that when somebody leaves, somebody marks it there the same day. If leavers are recorded two weeks late, the access will be withdrawn two weeks late, and the automation will have moved the problem rather than solved it.

The second is that every zone has a named manager who understands that answering those emails is part of the job. When there is none, the periodic review turns into an alert nobody opens, and a few months later somebody asks for it to be switched off because it is a nuisance. What is left is a high-end access control system with the feature that justified the price switched off.

It fits when the problem is the list and not the door: a lot of people, a lot of contractors, a lot of turnover, audits that ask who authorised what, and an IT department already used to requesting and approving access through a similar circuit in the IT systems. It also fits where strong identity credentials are needed and where the record has to hold up in front of somebody from outside.

It does not fit where there is nobody to ask. A company with a stable workforce, with one person who knows everybody and keeps the joiners and leavers straight, does not need this machinery: it would sit switched off and paid for. And it does not fit where the personnel system is not reliable, because then what has to be fixed first is in another department.

The day to day can not only be run by the client: it is run by people at the client who are not in security, and that is the point. The manager of an area approves the access for their zone, human resources triggers the joiners and leavers from its own system, and security stops being the counter every favour has to pass through. The classic tasks —cards, schedules, visitors, reports— are still theirs and are done from the web client.

What stays with the integrator is the structure of the two layers: new doors and controllers, buses, integrations with video and intruder detection, behaviour in an emergency, versions. And there is a middle ground particular to this platform: changing the approval circuits and the automatic granting rules. An IT department with a steady hand can take it on, and it is worth deciding from the start who does it, because a circuit half changed leaves access granted that nobody approved and the record still says yes.

For them to run it you need the usual —a document of the model, their own accounts, training by role— and two specific things. One: short training for the zone managers, who are not users of the system and are still the piece everything depends on; half an hour done properly and one page on what to look at before approving. And two: the procedure for what happens when nobody answers a review. If the answer is «nothing happens», the circuit is decorative; if it is «the access is withdrawn», people have to be warned before it happens the first time.

If the wall has controllers from that widely deployed family, they stay and only the head end changes. If the electronics have to change, the architecture of a main unit plus door modules lets you do it in small stretches —building by building or even storey by storey—, which fits annual budgets well. The reader cabling and the building work are almost always kept.

The credentials depend on the usual: that the readers read that technology and that the number can be imported in its exact format. And there is a case particular to this platform: if you are going to make the jump to strongly verified credentials, that is not a change of card, it is a change of process —how they are issued, who issues them, what is checked when they are issued— and it is worth treating it as a project of its own.