To have pretty much automated 90% of my job and pretend I'm very busy?

What you have done sounds really impressive.

I couldn't bear to just have 6 hours of work a week though and I would feel incredibly guilty doing what others have suggested and either taking on a second job or doing your own thing in work time. I'm genuinely quite shocked that so many people think you should keep quiet about all your spare time.

I would be telling my boss about all the innovations I had introduced, and offering to take on additional work, for example doing further work interpreting the data and flagging up key issues for the heads of year, or extending your improvements into other areas in the school.

The people working in those areas may not want to change the way they do things but I bet the school management would be keen to make the systems more efficient.

That @IroningBoardAgainstTheWall is exactly what I mean. So many people in schools - not just the one where I work - are overworked that they don't have the time to step back and work out how to improve things. Or they're too scared as they can just about manage very basic excel tasks and don't want anyone to realise how useless they are.
We had one person convince SLT she needed a side kick on a 0.5 contract as she had been asked to produce various bits of data. I heard about it, managed to set up a meeting to which I brought this one person who actually seems to know how to use a database and she set up a few things and this all happens automatically now.
Meanwhile, we have a "Phil" who is convinced of his own brilliance and not very nice to work with as he thinks he's indispensable and everyone tiptoes around him as he's convinced them too. Actually, he probably is indispensable for his own systems but I have a sneaky suspicion there must be better ways of doing it.
You've also reminded me that I think I should be able to streamline at least two aspects of something I do. I'm going to make that a project! But an efficient one!

But from your colleague's responses it seems they're assuming that you're working much in way Phil was and there's kind of a lie of omission going on?

But do they realise it takes very little time to do at this stage?

An interesting thread.
Folks with exceptional output are rarely appreciated and usually gaslit, some managers are convinced that people only have one success in them and when they've delivered it they should be shown the door.
I'd been working for 20 years when a man with a lot of imagination hired three of us - it was the first time any of us overachievers worked with likeminds.
We saved almost £100m before we were driven out - the best thing that ever happened to us, two of us earn three times as much, now that we understand our worth better.
@IroningBoardAgainstTheWall Don't give up your day-job or confess your lack of work.
There are maybe 30 useful functions in Excel, some only exist in 365, PivotTables terrify many, PowerBI is another beast altogether. Write a book that helps folks build confidence and structure their thoughts more usefully.
Depending upon your contract (are you paid for the holidays?) you could run courses to prepare those looking to enter the world of work or university - just make sure that your book is hardcopy, printed on coloured paper with a pale font to make scanning and sharing less easy.
There are legitimate ways of receiving the proceeds without causing PAYE issues and there are some other ways of selling your skills that will preserve your anonymity.
Well done for getting as far as you have.

And I expect you've never been bored since!

You sound fantastic. Independent schools are struggling at the moment due to the 20% VAT increase. Is the school financially viable? If in any doubt, look for something else.

In that case her own taxes are also subsidising her dossing.

I had a job similar to this. What took my predecessor all day I did to a higher standard in two hours max. He'd worked at this small company for decades and because no one else understood the job they didn't question his productivity. At each review, I expressed that I was bored to tears and was met with 'leave it with me' yet nothing materialised. Ultimately, I figured I was being paid for my work, not the time I spent doing it. When remote working kicked in during lockdown, I used the extra time to write a novel.

I'd carry on as you are while your daughter is little. Not ask for more work (it draws attention!) and take on a second job, something entirely remote like private sector data analysis, even data entry. Whatever, make money!! Then when daughter is older and settled find a job that challenges you.

I'd love to be in your shoes.

Well done @IroningBoardAgainstTheWall what you've done is great!!

If someone like the previous person had been in the role, they'd still pay them for the job and it's likely noone knows the systems like you do, so keeping you there is good for them.

I do wonder if you could make more £ by going freelance and having more clients. But I wouldn't rush to change anything right now cos it sounds like it suits your needs.

Should you fess up - for what benefit? They get their reports, they're happy. You do additional stuff when asked/needs be. It all sounds fine to me. I'd definitely use learning and development to fill my time if I was you.

Happy days!!!

Can I ask what training you have please? I would love to become proficient in data analysis!

My first thoughts ...

Keep it a secret. Let everyone think you're working at the same level as he did to deliver, and be seen as essential and indispensable. 😈

Work from home as much as possible .. and use the won time to run your own business, with an eye on emails and Teams calls. 😈

Do a big reveal announcement and a presentation on your huge automation project and how much it benefits the organisation, and hoover up the congratulations 😁

Let everyone know now - you could save the organisation so much money and time, make it more efficient, lead the roll out over different departments and branches etc. 😇

Bearing in mind that could lead to redundancies and 'efficiencies', including possibly you. 🤔

Please, please, please talk to other people in the school using databases and explain to them how to do their jobs efficiently. It pains me so much to see colleagues using databases in a way which must be inefficient if not incompetent as they just don't seem to be able to do anything other than manually and clearly that isn't the point of a database.
We have one person at work who I strongly suspect is in a similar position to you. My role involves me working with a number of different departments and I often take her along to seemingly random meetings as I know the question of data will come up and I want her to wave her magic wand and help that team realise that they can press a few buttons and most of it will sort itself out. This person and I have never had a direct conversation about whether she is underworked but she is always very happy to help and will continue to help for weeks. Her line manager occasionally splutters as she has such a complicated, time pressured job and is so busy but she tends to ignore him and come along to the things I've invited her to instead!

No but it seems obvious you have a lot more knowledge than they do and you do have the time. You could suggest you run some training sessions. I used to be a teacher and I put one of my learning objectives into AI and within a split second it gave me a fantastic Lesson plan.

Don't say a fucking word OP, you have increased efficiency and productivity for your role and you should be paid for that. You've also asked if you can do extra work, so the offers there, and they haven't given you any.

Agree that you should request to work from home part time so that you can use your extra time productively for your own benefit. Either getting stuff done at the house, downtime or a hobby.

If they don't let you work from home and they make you come in could you do anything like request extra training or qualifications? My sister in law got her employer to sponsor her masters degree which she did part-time along side her job.

Yeah and read books and do crosswords and get paid for it