The pioneering organizers of the ?rst UML workshop in Mulhouse France inthe
summerof1998couldhardlyhaveanticipatedthat in littleoveradecade
theirinitiativewouldblossomintotoday'shighlysuccessfulMODELSconference series the premier
annual gathering of researchersand practitioners focusing on a very important new technical
discipline: model-based software and system engineering. This expansion is of course a direct
consequence of the growing signi?cance and success of model-based methods in practice. The
conferences have contributed greatly to the heightened interest in the ?eld attracting much
young talent and leading to the gradualemergence of its correspondingscienti?c and engineering
foundations. The proceedings from the MODELS conferences are one of the primary references for
anyone interested in a more substantive study of the domain. The 12th conference took place in
Denver in the USA October 4-9 2009 along with numerous satellite workshops and tutorials as
well as several other related scienti?c gatherings. The conference was exceptionally fortunate
to have three eminent invited keynote speakers from industry: Stephen Mellor Larry
Constantine and Grady Booch.
