One of the big problems with BARIS was that you had to basically do everything yourself -- recruit astronauts, then 'handhold' them into basic training then advanced, and finally assign them to missions. It was...somewhat doable with the Mercury era astronauts, but by Gemini and Apollo, with at least 20+ astros in the system, things broke down, when you had to do that and juggle program development/assignment elsewhere.
At one point, I actually began to plan things out using a simple Excel-based planning chart to remind me of what decisions to make, and where. Unfortunately, I didn't save it, so I can only show you a mockup which I put together in a minute or two; It has no bearing to the actual chart I made:

Something like this would be invaluable in SPM, to show how projected and planned trends "line up"; and to set in stone future recruitment dates; e.g. telling the AI to automatically recruit astronauts at specific dates.
It would also be really helpful if you had an AI 'agent' to play the role of 'Deke' in the game; to automatically place the new astronauts into basic training, then into advanced training depending on their proficiencies, etc; freeing you up to work more on higher level decisions.
You of course, would be able to override "Deke's" decisions; maybe an astronaut actually writes directly to you in your role as Space Program Manager and protests that he's been assigned to "Advanced Training, Command moduel" when he wants to be a lunar module pilot, and if you don't give him his request, he might take a hit in "morale", or whatever.



