This is a post by Emma Rudeck on the Concurrent Engineering Site.
Design intent of a CAD model and the logic behind specific design decisions are often documented in numerous locations, including paper notebooks, emails and Excel spreadsheets. But, since this documentation is disconnected from the CAD model, it can easily be lost over time.
WITH THE SIGNIFICANTLY IMPROVED INTEGRATION BETWEEN PTC MATHCAD PRIME 3.1 AND PTC CREO, THIS DOCUMENTATION CAN BE AT THE HEART OF THE DESIGN.
This means that engineers and designers can create a digital notebook that can be embedded into their CAD models. It also enables them to drive bi-directional communication between the applications.