From entry path of change in glossary Human Computer Interaction the Basics
Often a new solution or new product would be perfect at future point once it is installed, or once everyone uses it. However, it is not sufficient for there to be a prefered end state or goal, there also has to be a path<.em> of change, a way of getting from the current situation to the new one. This needs to be an integral aspect in design to ensure the adoption of the new product.
For example, is a new product compatible with old documents or data formats, or will there have to be a major conversion process? Will users have to retrain? For a communication or collaboration system there is often a critical mass of users: if there are too few users the cost of use exceeds to benefits, but once you have reached that critical mass, there is clear advnatage for each new user. The key issue is how to achieve the critical mass.
Links:
ixdf.org: IxDF: Managing the Path of Use- alandix.com: Designing for adoption and designing for appropriation