Cameron Wills, AlanEvans, AndyFrance, Robert B.Moreira, Ana M. D.Rumpe, Bernhard2020-01-072020-01-0720013-88579-335-0https://dl.gi.de/handle/20.500.12116/30861I have always been a strong believer and practitioner of the JFDI approach to development, which yields high morale, early identification of problems in design and of any misunderstandings of the requirements, and easily tracks changing needs as they occur. I applaud eXtreme Programming [Be00] for enunciating some excellent guiding principles that separate this approach from iterative hacking. And yet I also have always believed in using models to understand abstractions during the design; and to communicate them to others both during the design and afterwards. The one aspect of XP I’m not keen on is the disdain for documents and models other than those enshrined in the code and tests. Nevertheless, it’s undeniable that any documents separate from code and tests can and will get out of step with them, and will not be read. This position paper outlines some of my experience, as a consultant methodologist with a number of clients, in attempting to get the benefits of XP at the same time as those that follow from using modeling techniques.enText/Conference Paper1617-5468