Information Technology Reference
In-Depth Information
The execution node
The execution node, as seen from a black box perspective, is the component that receives
the process definitions (a description of each step that must be followed; from here on,
we'll just refer to them as processes). Then, it executes all the necessary steps in the estab-
lished way, keeping track of each step, variable, and decision that has to be taken in each
process's execution (we'll start calling these process instances).
The execution node along with its modules are shown in the following figure:
The execution node is composed of a set of low-level modules: the semantic module and
the process engine.
The semantic module
The semantic module is in charge of defining each of the specific language semantics, that
is, what each word means and how it will be translated to the internal structures that the
process engine can execute. It consists of a series of parsers to understand different lan-
Business Scenarios
.
It is flexible enough to allow you to extend and support multiple languages; it also allows
the user to change the way already defined languages are to be interpreted for special use
cases. It is a common component of most of the BPMSes out there, and in jBPM6, it allows
you to add the extensions of the process interpretations to the module. This is so that you
can add your own language parsers, and define your very own text-based process definition
language or extend existing ones.
