yeah, ok. Sorry...
Ok.. The goal of aircraft production is to make planes. That is the ONLY function of it.
Therefore, the AI needs to decide which planes to make. The AI uses a weighting system to decide what to build, the higher the weight, the more chance there is to build it. Factors that come into it are How many are in stock, how many are in use, how many are needed (if there's a deficit).
What it then does is look find what airframes are needed, then change anything with an excess to the new type. There must be a significant excess before it will be changed over - like at least 50% reserves, and that's only for AC in demand - things with one or two gruppen will be fairly change resistant, needing 100 days prod in the kitty (so 2 in prod means it won't change till 200 are in the pool)
Then it checks to see what is in excess. If it finds anything it will convert some to research, and some to other types, if they are in huge deficit. It will also see if there's spare airframes sitting around, and change away from them if it needs to.
With the what-to-produce done, the system then looks at the requirements. If there's a deficit in parts or engines, it will change something over. Again, it will change things only if they are not needed, or if there is a huge stockpile. It also does one trick if it finds that there are heaps of spare airframes, but the engine or part stock is low (1 - 2 days) and there are supposedly sufficient items in production, it will increase the production beyond requirements to clear the backlog.
The final thing it does is look at what engines and parts are in prod but not needed. It will find something to change to, but if it can't, then it just sits. The AI isn't losing anything, they're genuinely not needed, so why change?
Now all this works fairly well. Not perfect, but not bad.
gigiddy gigiddy gig-i-ddy