Components of the Design
Having glimpsed the BPM architecture “from 30,000 feet,” we now descend to a lower altitude to get a closer look at each of its major components. This section examines the requirements and proposes designs for the notations and graphical tool, the runtime engine, the human and system interaction interfaces, the administration and monitoring facilities, and the CDL toolkit.
Notation and Graphical Tool
The need for a graphical process modeling language is often overlooked in the BPM standards race. Most BPM languages are XML-based and can be relatively difficult to compose or read. Design is best communicated with diagrams. Scan through a typical object-oriented component design document, for example, and you will discover that a single UML class diagram can convey most of the intended meaning, making many of the surrounding words redundant. If a picture is sufficiently rich, it is worth more than a thousand words! Standardization adds even more value. A diagram that is drawn to a standard specification is familiar to a wide audience, and its semantics are also clearly understood. Readers get the gist of a haphazardly drawn assemblage of boxes and arrows, but the lack of precision in representation makes it less intelligible.
BPM has two good graphical modeling notations—BPMN (Chapter 6) and the UML activity diagram (Chapter 3)—but BPMN is the preferred choice for our architecture because it is more expressive (it supports most of the “P4” patterns described ...