Yes in my view a conventional test switch is still required.

This is is still expected, demanded, or required by most clients and their consultants, or maintenance contractors, even if needless.

No, if the self-test system can perform the monthly and annual tests then a key-switch is not required. Self test systems should be in accordance with BS EN 62034.

Clients might still request one to facilitate a manual test for spot checking the auto system or because "that's what we always have" (not a great reason but hey, if they want it and will pay for it, it's their choice).

Is the 3 hour duration test only required once a year? Or is it required more frequently? Am trying to assist a charity run building but am not a E/light specialist. I gather the quick on/off check is required monthly but don't know about the 3 hr one. On the fittings I have replaced, I always disable the self-test jumper setting because they are used to using the key switch test points already provided, and asking them to check for red/yellow/orange indicator lights would only complicate the issue.,

I have spoken with some expert in this topic and he said that the test key switch is still required even though if the lights are self-testing type as we need to have some point of isolation of the lights for service or maintenance purposes, unless there is a possibility of isolating them directly from the fuse however, the distribution board must be reachable ideally in the same room/area. 

Isolation can be achieved at the distribution board by operation of the MCB/RCBO.

Annual testing for full duration. However self-test systems will usually stagger their testing so that the whole installation isn't under test at the same time.

I am led to understand that isolating at the main mcb is not recommended due to inconveniencing other occupants of the building, and that a test switch is the desirable method.

Yes, that's what I mentioned above but apparently the DB with the designated MCB needs to be somewhere close to the circuit or component being serviced. I am not sure how far or how close though. 

It's not a requirement, but that's where the discussions with the client come into play for how they envisage the building operating. The key test switch doesn't normally isolate the circuit, just breaks the permanent live to the emergency fittings. For maintenance you'd still need to isolate at the board, but for phased manual testing, distributed key switches are good. Self test does away with that though.

Tom D said:

I have spoken with some expert in this topic and he said that the test key switch is still required even though if the lights are self-testing type as we need to have some point of isolation of the lights for service or maintenance purposes

But aren't most fishtail switches to the same standard as ordinary plateswitches (e.g. BS EN 60669-1) - so, according to table 537.4, not suitable for isolation?

   - Andy.