Advanced Building Simulation

200 Augenbroe
Figure 8.7 Sample ExEx startup screen (from COMBINE report).
Figure 8.7 shows a screenshot of the implemented Exchange Executive (ExEx)
(Amor and Augenbroe et al. 1995). The event model is read by the ExEx, which is
then automatically configured to assist the project manager at run time to decide
which application can be executed next, and which applications are affected by
changes to the Building Model and therefore need to be rerun. The state of the project
moves as tokens through the network of “places” and “transitions” on the screen.
It allows a team manager to decide whether a simulation software can be deployed
next, based on the automatic checking of constraints.
It has been stipulated in this section that interoperability requires more than a
shared Building Model and a set of applications with appropriate interfaces. Two
major data and process management components have been shown to be necessary
to implement interoperable solutions in practice.
The scoping of realizable and manageable systems remains an open issue. There are
conflicting opinions on the size of integrated systems that can be built with current technology.
Many attempts have suffered from a lack of well-defined scope. Figure 8.8
introduces a scoping approach, which has proven to be a helpful instrument in determining
the size of integration efforts in general. The figure explains the difference
between unscoped approaches that emphasize the generic Building Model, versus wellscoped
definition of smaller Building Models in a number of separated and fairly small
process windows. Each process window or “Project Window” (PW) is defined by the
actors and life cycle stage that it covers. Useful PW can be identified by detecting clusters
of tightly knit software applications in a particular phase of a project, involving a
relatively small set of actors. Once a set of PWs have been identified, integrated systems
can be targeted at them. The exchange of data across the borders of a PW is left to userdriven
(traditional) procedures, involving data filtering, translation, and population of
the PW-specific Building Model. These interfaces typically do not fall in the category of