That's an interesting theory for sure - I see some portions of it happening but best guess looking at the pattern differs from yours in a few ways.
I suspect that the citizenship 'test' system is completely automated as a step and only until that test cycle gets completed does it then proceed further.
This test cycle still seems to be functioning as a limit of concurrency and a limited number of slots (this is either due to it never really leaving the supposed 'pilot' phase it's been in since, what...January)? This means that only a certain number of people (possibly 5000), with allocations distributed across the various CPCs that can be eligible to give the test at any one time.
This is conjecture at this point but the cycle seems to have a few phases in it that seem to be directly tied to the automated system:
1.
'Soft Reservation' - Slot released pending verification, Notification provided to candidate in tracker of upcoming test window. This is the bit we all get excited about, because well...movement!
It means that the previous candidate occupying the slot has likely completed the test and is pending verification before it can be formally 'closed'. This would also explain why the notification of this is so far in advance of when the actual test window is - it's literally buffer-time to accommodate for any glitches or if a re-alloc (possibly through a set of reserved emergency slots to be used at the CPC's discretion) would be needed for the slot without disrupting the next candidate (who got said notification that they were up for a test).
2.
'Hard Reservation' - Formal e-mail received with test window provided, post verification that the previous candidate who occupied said slot is in the clear and everything is good to go. This basically means that the candidate is now locked in with a dedicated slot for them to do the test and a window for them to do the test in.
3. Candidate completes test - At this point, one of either two things happens:
- The slot is immediately soft reserved for someone else (Step 1) while they verify your result was registered successfully on their system and/or has gone through any of their fraud detection systems (those pictures they supposedly take at random, for example - an automated process).
- (To your point, @OllySyd ) They enter a 'free slot' queue where a batch job (probably run daily or maybe every 12 hours) that takes care of notifications runs through it at a set point each day to update the tracker - while it might seem like it's batches of 5, in reality at scale it might be much larger and basically just looks at all the freed up slots and runs through the queue to select the next batch of candidates to associate a soft reservation to. The only way we can ascertain if that's the case is to see the time that all of your events registered in the system to guess when this job seems to run (similar to how we know that the updates to the old eCAS used to happen around 7:00 AM daily)
This cycle then continues down the queue. So in a way, these updates on the tracker are a means of advance notice before the actual e-mail is received, in my eyes. Candidates who have been 'released' from the testing cycle (aka have given the test, had it register successfully and haven't set off any sort of automated fraud detection flags) are then put back into the system for either any additional processing that is needed or in a queue for interviews/oaths.
The biggest problem/mystery to me is the limited number of 'slots' to take this test and the allocations of said slots to different centres nationally. Also the relevance of the testing cycle needing to be from the same allocation pool as the CPC processing your case seems...unnecessary if they're a different system. But who knows?
