This work provides an overall framework and tools that together substantially reduce the time and effort required to construct process models that are fit for purpose. These key factors are: (a) the efficient reuse of existing model information, (b) the development of a multi-model environment, and (c) the characterisation of models through appropriate model metrics. The paper concentrates on tools to improve current modelling practice, and describes a framework addressing "Model Families" in which these tools can work together for greater productivity. A Model Family is a hierarchical collection of models which provide many different representations of the same system. These are collated in a manner which focuses on the similarities and differences between each model in the collection. The specific differences between individual models are recorded as model members. Activating a particular member sees it take dominance within its family of alternatives, becoming an active part of the model description. The use of families and members makes it possible to store a large number of models of the same system in the one computer document, encouraging information reuse, and allowing the development of advanced meta-modelling tools which can potentially deliver substantial reduction in model development times. (c) 2007 Published by Elsevier Ltd.