A Poor Man's APSNot many of us were around at the birth of MRP but I, at least, remember when it was the preserve of the large company with money to burn.
I was around, though, at the birth of APS (Advanced Planning and Scheduling systems) and, yes, they are currently the preserve of the large company with money to burn. My definition of APS is a system that simultaneously recognises both material and capacity restraints and recommends an optimal solution accordingly. By this definition, admittedly, not all systems sold as APS are APS.