Merging Partial Behavioural Models;
ACM SIGSOFT Software Engineering Notes
ACM Digital Library
Abstract: Constructing comprehensive operational models of
expected system behaviour is a complex and costly task.
Consequently, practitioners have adopted techniques that support
incremental elaboration of partial behaviour descriptions. A
noteworthy example is the wide adoption of scenario-based
notations such as message sequence charts. Scenario-based
specifications are partial descriptions that can be incrementally
elaborated to cover the system behaviour that is of interest.
However, how should partial behaviour models described by
different stakeholders with different viewpoints covering
different aspects of behaviour be composed? How should partial
models of component instances of the same type be put together?
In this paper, we propose model merging as a general solution to
these questions. We formally define model merging based on
observational refinement and show that merging consistent models
is a process that should result in a minimal common refinement.
Because minimal common refinements are not guaranteed to be
unique, we argue that the system modeller should participate in
the process of elaborating such a model. We also discuss the role
of the least common refinement and the greatest lower bound of all
minimal common refinements in this elaboration process. In
addition, we provide algorithms for i) checking consistency
between two models; ii) constructing their least common refinement
if one exists; iii) supporting the construction of a minimal
common refinement if there is no least common