I added sound when you click on the building.

what is updated on latest version?

Hey thanks so much for telling me how real world electronics are made.

I'd say 1500-2000 people IRL. ))) Depends on what exactly we're making. But remember, we're in the game. A factory like that would be too hard to maintain.
Let's say we produce TVs. Each one weighs about 15 kg. Then 12 tons, that's 800 TVs. The bottleneck is the final assembly division. That's about 5% of the staff. (Don't ask me why. It's a balance.) If you have only 800 people working, then 40 of them (every one) have to assemble 20 TVs per shift. It's normal in the 2000s, but in the 60s-80s, assembling 2.5 pieces per hour is just unreal.

@keng I was wondering if 800 workers for 12 tons a day is realistic or if it should be more like 1200 workers.

Yeah you're right I probably could reduce the amount of production to mean that it requires a second factory / more workers.

I'm an electronics engineer, so it's hard for me to be under game restrictions. :) But...
There are about 20-30 workers per engineer. For a game, I would assign 10 to 1.
12 tons of output for a plant of this size is fine. Yes, one trailer per shift is OK. But such a plant would employ over a thousand people. For the game, I would reduce the output.
Chemicals are used, yes, but not in such quantities. IPA for cleaning, various solders, all sorts of little things... It could be 100-200 kg a day IRL.
In the early days, aluminum and mechanical parts were used more. Nowadays, plastic and electronic components are used more. But we cannot change the consumption of individual components.
I would distribute them approximately like this: 35% plastic, 20% aluminum, 25% electrical parts, 20% mechanical. That is, about the same as yours. But this is something average. And it doesn't make any sense for the 60s and 70s, and it doesn't make any sense in the 2020s.
I don't have one correct solution.

I'm interested what improvements would you suggest.

I agree about aluminum and chemical components. The separation between workers and engineers is also correct. (But not the ratio.)
But about the balance... we need to think about it.

Merci beaucoup, j'apprécie particulièrement l'augmentation du nombre d'employé

I call it balanced because it more accurately reflects real world production and doesn't crash your economy.

Just a cheat with changed production data.
How can you call this "MOD" to be balanced?