This is a post by Dave Martin on PTC site.
As an engineer for decades at multiple companies, I have repeatedly seen the same problems and complaints in product development.
“We move too slowly.”
“The project lacks leadership.”
“We’re never going to make our unrealistic schedule.”
That may be because traditional product development programs follow a Waterfall methodology. Think of a Gantt chart; you have distinct heavily planned sequential phases, such as concept, design, prototype, test, and production. A design review gates each phase.