As operations of organizations are described as business processes, the number of business process models that organizations develop and have to maintain increases. It is essential to develop business process model repository technology to manage thousands of process models. The goal of this book is to describe techniques that improve on existing BP Model Repositories, by improving the management techniques that are supported by these repositories on an aspect that has received little attention so far. To achieve this goal, a survey of existing business process model repositories is made, with a framework of business process model repositories as the outcome. At the same time, the survey identifies that efficient process retrieval is not yet supported. Therefore, an indexing technique is proposed to make process retrieval at least one order of magnitude faster than current techniques.