Date[ June 24, 1998]  Recordnr[        ]  Stored[ Composition papers
Who[ M.-C. Shan, J.W.Davis, et al
Title[ Business Process Flow Management and its Application in the 
Telecommunications Management Network

Published[ HP-Journal, October 1996

Keywords[ workflow, composition, 

Comment[ 

Summary[ 
The paper describes HP OpenPM, now called changengine and used by 
several banks. It is advanced workflow technology based on a framework 
approach for reusability.

Goals of changengine:
- substantial evolution from traditional workflow technologies
- for distributed heterogenous computing environment (several procotols 
via wrappers)
- it is a middleware system for procedural automation of a business 
process by managing the sequence of process activities, including the 
invocation of appropriate human, instrument or computer resources.
- content, structure of process can be preplanned or ad hoc

Main elements:
- Process engine: based on the business process definition (graphically, 
rules) the process engine determines when something takes place and 
triggers activities.
- Resource executive: manages resources
- BOW: business object wrappers

Definition of process:
Graph containing work nodes and rule nodes. Each work node can again be 
a process containing work nodes and rule nodes. Work nodes have status 
initial or fired. 
Forward arcs denote normal execution flow, and they form directed acylic 
graph. Each work node can only have incoming arc, whereas rule nodes can 
have several incoming arcs (they have rules to deal with that). Both 
kind of nodes can have several outgoing arcs.
Backward arcs are reset arcs, i.e. when they fire, everything in their 
loop is reset, and started tasks are aborted.
Nodes fire like in a petri-net.
Rules: e.g. "if Customer.approval = TRUE then arc 5"
Events: rule nodes can also raise evens, which themselves can fire rules 
nodes that have subscribed to that event. Events are modelled like 
specific kind of nodes, like a shortcut for not drawing to many arcs 
across the graph.
This kind of graph allows to describe:
- sequencing and timing and dependancy of business activities,
- data and physical agent allocation of business activities
- business rules and organization policies 

Mapping of process definition to execution:
Work node -- process activity(task) -- invocation of an operation on 
business objects(resource) during execution of a process

BOW:
BOW's wrap business objects and interface to the process engine via 
CORBA. Towards business objects they interface with various protocols, 
e.g. also DCOM and DNA. Business objects are catalogued in a library.
Interfaces: from process engine are CORBA and WfMC (Workflow Managmenet 
Coalition standard interface)


Optimization:
Data handler: allows seperation of application specific data and 
process-relevant data needed for rule nodes, thus reducing amount of 
data flow.
Resource manager: for automatic workload balancing.
Statistical data: bottleneck analysis, flow optimization.

References: 
- paper gives further references (not very new)
- Reed Letsinger and Michael VantHilst at HP labs
- webpage: www.pwd.hp.com/cyc/af/50/  is behind firewall