NOTE: If an electronic version of a
paper is not available here, or you are unable to successfully download
the paper that you want in the formats available, please contact MIT
Document Services at (617) 253-5668, DOCS@MIT.EDU.
Please do not contact the authors for copies of papers.
CCS No. 216, Sloan No. 4159
Defining Specialization for Process Models
George M. Wyner and Jintae Lee
and design methods take full advantage of the object specialization hierarchy
when it comes to modeling the objects in a system. When modeling
system behavior, however, system analysts continue to rely on traditional
tools such as state diagrams and dataflow diagrams. While such diagrams
capture important aspects of the processes they model, they offer limited
guidance as to the ways in which a process can be improved. In this
paper we extend the notion of specialization to process representations
and identify a set of transformations which, when applied to a process
description, always result in specialization. We analyze specific
examples in detail and demonstrate that such a use of specialization is
not only theoretically possible, but shows promise as a method for categorizing
and analyzing processes. This paper makes two contributions toward
answering this question: first, it articulates a formal definition of process
specialization which is compatible with object specialization but allows
us to reason specifically in terms of process representations. Second,
it develops the concept of the "specializing transformation" as a means
for systematically generating and exploring process alternatives.
We illustrate these results by applying them to two commonly used representations:
the state diagram and the dataflow diagram. We identify a number of apparent
inconsistencies between process specialization and the object specialization
which is part of the object-oriented approach. We demonstrate that
these apparent inconsistencies are superficial and that the approach we
take is compatible with the traditional notion of specialization.