  In this thesis, we focus on the proposal of distributed workflow systems
dedicated to the automation of administrative business processes. We propose an
approach to build such systems by relying on the concepts of multiagent
systems, Peer to Peer (P2P) architecture, Service-Oriented Architecture (SOA)
and structured documents (artifacts) cooperative edition. Indeed, we develop
mathematical tools that allow any workflow systems designer, to express each
administrative process in the form of an attributed grammar whose symbols
represent tasks to be executed, productions specify a scheduling of these
tasks, and instances (the derivation trees that conform to it) represent the
different execution scenarios leading to business goal states. The obtained
grammatical model is then introduced into a proposed P2P system which is in
charge of carrying out the completely decentralised execution of the underlying
process's instances. The said system orchestrates a process's instance
execution as a choreography during which, various software agents driven by
human agents (actors), coordinate themselves through artifacts that they
collectively edit. The exchanged artifacts represent the system's memory: they
provide information on already executed tasks, on those ready to be executed
and on their executors. The software agents are autonomous and identical: they
execute the same unique protocol each time they receive an artifact. This
protocol allows them to identify the tasks they must immediately execute, to
execute them, to update the artifact and to disseminate it if necessary, for
the continuation of the execution. Moreover, actors potentially have only a
partial perception of processes in which they are involved. In practice, this
means that certain tasks can be carried out confidentially.
