JTF ATD Core Plan Representation Workshop
Austin Tate (firstname.lastname@example.org), 20-Jun-96
This page provides notes of Austin
Tate's input for the July 1996 Workshop on the JTF ATD Common Plan
http://projects.teknowledge.com/CPR/cpr.html) which in turn may give
input to the C2 Schema used in the JTF ATD.
A related information page is available
A description of my proposed approach to Mixed Initiative Planning
(mutually constraining the space of behaviour) and its
relationship to the <I-N-OVA> constraint model of activity is
- If different applications have different views of planning, is
it possible for them to externalize these views, so that they can
operate on a common model? What are these different views, and what
is this common model?
Yes, so long as an appropriate hierarchical structure is employed. I
suggest that we follow the Process Interchange Format (PIF) model of a
small core representation of Process and Activity (largely compatible
with IDEF) with its "Partial Shared View" (PSV) extension mechanism.
- How should a core plan representation support mixed initiative
planning and partial plans?
Adopt a model of plans being constraints on the legitimate
behaviours in the domain. Mixed initiative is possible if all
agents (system and human) involved in the planning process share a
view of the planning process of mutually constraining the
behaviours desired (by setting, analysing, modifying and using the
constraints). This means having a model of activities that are
possible in the domain, and an extendible representation for
all the constraints that are possible on those activities.
- How should a core plan representation support uncertainty?
Specifically, how can a user encode information about alternative
actions, assumptions, predictability, and range of possible outcomes?
Constraints naturally allow spaces of alternative elaborations of the
partially specified plans.
- How should a core plan representation address the goals of both
simplicity and scalability? How can the representation and user views
support a range of planning needs?
A core process/actrivity model extendible with partially shared views
(shared between those systems needing the additional information, but
sharing the core or deeper models as necessary). Separation of the
model from model views is essential anyway, and can support technical
plan views or world oriented simulation or animation views.
- What are the kinds of user interactions with plans that we
should be thinking about? What does an individual need to do? What
kinds of group dynamics need to be supported?
We should be seeking an uniform interlingua between system components
and between the various roles of users involved which seeks to
communicate constraints on the mission taskings, options being
explored, authority, world state, geographical/spatial, resource and
other constraints. Ways to present this interlingua information in an
acceptable form to the various agents (humans and systems) involved
should be explored.
- What lessons can be learned from previous efforts at designing
common plan representations?
- They must be extendible and changeable should the previous
decisions prove wrong. The process of allowing such change should be
an early requirement to assure everyone involved that this route will
be long lived.
- They must not be over-large or verbose.
- Detail should be confined to those systems that need to share the detail.
- Consensus should be reached by those involved. Go as far as
possible within the group view, but not so far that part of the group
- Are there existing tools and methods outside of JTF which the
core plan representation should be compatible with?
- Process Interchange Format version 1.1
- Workflow Management Coalition Interface 1: Process Definition Interchange