Before the 1960s engineering departments were staffed and led by practitioners, providing a highly vocational training. In the 60s a golden age of engineering education was ushered in by an influx of engineering scientists, leading to a balanced engineering education teaching powerful scientific explanations alongside the practitioner’s experience based approaches.
The CDIO initiative looks to fix this: they say that engineers all do essentially the same thing:they Conceive, Design, Implement and Operate Solutions to engineering problems. CDIO enthusiasts say that this is the context in which we should teach everything.
I suspect that the terrible track record of PBL in the educational literature might be to do with who was applying it. Medicine and law have made heavy use of practitioner-led PBL for many years, and whilst not as effective as is commonly believed, the evidence suggests that it is an effective way to teach professional skills which are both hard to measure and to teach in a didactic way.