NEG — Separation of Collaboration from Encounter inheritance.

Negotiation FTF, CollaborationFramework module.
The definition of Encounter combines the notion of a
Membership and rules relating to member association
with rules relating to process execution (e.g. derived
Collaboration interface). In the case of Collaboration
the current inheritance model eliminates the possibility
for independent declaration of process focuses role
models as distinct from the roles attributed to different
members of a membership. While the object model
expressing roles from the two different perspectives
are equivalent at an interface level, the instance
values and lifecycles are independent. It is recommended
that the notion of Encounter be restricted to the
management of a set of members, sharing a common view
on a collaborative process execution. Moving the
collaboration process semantics out of the Encounter
inheritance hierarchy can be achieved by defining a
relationship between Encounter and the active process
that an Encounter is co-ordinating. Once the notion of
process is separated from the notion of membership, the
respective control models can coexist. Secondly, given
formal separation of Membership and process, the existing
usage relationships derived from the inherited
Task interface by Encounter can be used to manage the
subject of collaborative interaction - as such, the
subject relationship can be removed from Engagement,
Voting and Collaboration.

Resolution:

• introduced explicit definition of a processor as a
  base type for collaboration, associated to a Task by
  a declared relationship
• introduced explicit definition of a processor as a base
  type for Collaboration (as per Task Session notion of
  Task and processor)
• retract the association of a subject of a collaboration
  in favour of the existing usage relationships between
  a processor and a Task.

see below