@InProceedings{Giese+1999f,
  AUTHOR = {Giese, Holger and Graf, Jörg and Wirtz, Guido},
  TITLE = {{Seamless Visual Object-Oriented Behavior Modeling for
  Distributed Software Systems}},
  YEAR = {1999},
  MONTH = {September},
  BOOKTITLE = {IEEE Symposium On Visual Languages, Tokyo, Japan},
  PUBLISHER = {IEEE Press},
  PS = {vl99.ps.gz},
  ABSTRACT = {To ease the development of distributed systems, the visual
  notions for the structural aspects of object-oriented analysis and
  design should be combined with techniques handling concurrency and
  distribution. A novel approach and language for the visual design of
  distributed software systems is introduced and illustrated by means
  of an example. The language of OCoNs (Object Coordination Nets)
  is integrated into the structuring mechanisms of the UML standard
  for object-oriented analysis and design. Such an object-oriented
  notation is crucial for handling complex software systems and can be
  extended with the graphical expressive power of Petri-Nets to also
  describe concurrency and coordination. The same visual language is
  used to specify the interfaces and contracts of software components,
  the resource handling within a component as well as the control flow
  of services.}
}