By the early 2000s, function-by-function optimization within the company had reached its limits, and was no longer able to cope with competition, particularly from "low-cost" countries. A global vision of product development processes became necessary to eliminate the costs induced by breaks in information sharing between engineering and the company's downstream functions (methods, manufacturing, after-sales). This led to the new ambition of extending the scope of observation to the entire company.
Basically, it's a question of moving from applications developed in silos, to a global corporate vision in which the various players, notably manufacturing and after-sales, are involved very early on in the design process, in order to anticipate potential difficulties in the "field" and thus considerably reduce development costs and timescales.
The term PLM (Product Lifecycle Management) was coined to describe this more global vision.