I first learned and used p3 and Herlihy Mid-continent Company installed the big graphic printers. Our project managers all maintained some kind of a schedule on each project but we never attempted to combine them to figure out equipment or creww availability although we did do that manually to some extent. I later worked at Burns and made them purchase p6. One project manager, Paul Sales used it to complete a complicated Metra project in Barrington, IL. Upper management resists using it because their “seat of the pants” decisions are usually wrong if compared to a cooperatively developed schedule.
Less bells and whistles that I never used compared to p6.
Nothing of importance that I can remember.