FACILITATING BUSINESS PROCESS MANAGEMENT
WITH HARMONIZED MESSAGING
1
Shazia Sadiq, Maria Orlowska
School of Information Technology and Electrical Engineering
The University of Queensland, Australia
Wasim Sadiq, Karsten Schulz
SAP Corporate Research Centre Brisbane, Australia
Keywords: Business Process Management, Workflows, Middleware Integration, Messaging
Abstract: Process communication is characterized by complex interactions between heterogeneous and autonomous
systems within the enterprise and often between trading partners. An overwhelming number of initiatives
and proposals are underway to provide solutions for process specification and communication. However, the
focus is often on defining APIs and interfaces rather than the semantics of the underlying message
exchange. We see a great potential in the enhancement of current messaging infrastructure, in its new role in
facilitating complex, long running interactions for dynamic and collaborative processes operating in
decentralized environments like the web. In this paper, we primarily present a vision for a technology aimed
at providing a level of harmonization to multiple messages to form a single custom definable backbone. We
will provide the foundation framework for the harmonized messaging technology and identify fundamental
issues for the specification of such complex interactions.
1
This work is part of a project jointly funded by the Australian Research Council, SAP Corporate Research and The
University of Queensland
1 INTRODUCTION
Tremendous developments in data storing,
processing and communication over the last two
decades have made unprecedented impact on how
most companies operate, develop future business
strategies and deal with day-to-day operations.
Commonly available networking and expansion of
the access to the Internet have changed the way we
reason about system architectures, with integration
becoming an obvious and preferred option.
The research efforts and development paths
pursued by many academic groups and system
vendors, targeting heterogeneous system integration,
have not been easy and have not always delivered
effective and practical results which could make a
real impact on how the future solutions are to be
constructed. Many lessons have been learnt from
these research outcomes. They outline the clear
boundaries of feasibility when dealing with building
new applications out of existing and
useful/deployable components (Colomb &
Orlowska, 1994). These conclusions are not only
related to the technological aspects of integrated
structures, such as the middleware, but also to
semantic issues of terms used across multiple
systems. In particular, the need for a complete and
extensible ontology that expresses the basic concepts
that are common across a variety of domains,
became apparent, forming a new research direction
over the last few years (see e.g.
www.cs.rmit.edu.au/fedconf/odbase/2002/ )
Workflows Management Systems (WFMS)
delivered effectively in the area of process
enforcement, offering a clear separation of business
process logic from component applications involved
in process execution, thereby responding to the well-
established need for application integration. It is an
observed phenomenon that a new IT solution often
30
Sadiq S., Orlowska M., Sadiq W. and Schulz K. (2004).
FACILITATING BUSINESS PROCESS MANAGEMENT WITH HARMONIZED MESSAGING.
In Proceedings of the Sixth International Conference on Enterprise Information Systems, pages 30-36
DOI: 10.5220/0002634900300036
Copyright
c
SciTePress
triggers additional, and even more advanced user
requirements, which probably would not be
discovered if the current systems functionality
would not be so widely available. This pattern can
be clearly observed in the context of workflows
technology evolution.
In Figure 1, we show building blocks of process-
enabled enterprise systems. Just as the DBMS
provided a means of abstracting application logic
from data logic, the WFMS provided a means of
abstracting coordinative process logic from
application logic. Clearly, every generation has
provided additional functionality through supporting
systems. Although, workflow technology has
delivered a great deal of productivity improvements,
it has been mainly for pre-defined static and
repetitive business processes, that required basic
level of coordination between human performers and
some application components. More recently
business process management (BPM) has been used
as a broader term to reflect the fact that a business
process may or may not involve human participants
and may also cross organizational boundaries
through messaging infrastructures. The role of
business process management systems must now be
extended to provide additional functionality to
support configurable, coordinative and collaborative
processes and a much more sophisticated level of
integration (desirable characteristics of current
business process management systems). This need
arises from expanding business requirements for
cross-organizational process communication.
Examples of such processes can be found:
in globalization of many manufacturing
companies where different product parts are
developed at different locations by different
organizations,
in a new wave of e-commerce applications
where a great deal of outsourcing is the norm,
in financial services with emerging subsidiary
agencies sharing work practice,
and recently, in new non-traditional application
domains for business process technology such as
e-learning, where cross-organizational units offer
new educational services that would greatly
benefit from integration.
Only an integration technology that offers rapid
and easy integration procedures, requiring only
minimal IT expert intervention, can be
successful at multiple and diverse,
geographically spread e-business environments.
The great challenge for IT specialists now is to
find a functionally rich and technically feasible
balanced solution for this overall complex
problem of integration taking into account
technological and semantic limitations.
Figure 1: Building Blocks of Process-Enabled
Enterprise Systems
2 CURRENT TECHNOLOGY
SOLUTIONS AND RESEARCH
DIRECTIONS
There is currently a drive towards advancement of
the technologies surrounding the e-business domain
(See e.g. 3rd VLDB Workshop on Technologies for
E-Services TES'02, and Workshop on Web
Services, e-Business, and the Semantic Web
(WES):In conjunction with CAiSE'02)
Businesses are increasingly moving towards
extensive automation of their private and public
processes. This automation takes the form of
complex interactions between heterogeneous and
autonomous systems within the enterprise and often
across multiple organizations. Controlling these
complex interactions in order to effectively manage
collaborative business processes is known to be a
critical yet difficult problem using current
technology solutions. Consequently, the areas of
consideration are multi-faceted ranging from
security, reliability and transactionability, quality of
service guarantees, process validation, optimisation
to semantic integrity of terminology used. The
industry is currently flooded with initiatives and
proposals towards e-business standards. These
standards encompass trading partner agreements,
business process specification, application
integration, and network protocols.
Integration technologies such as brokers,
application adapters, portals and messaging are
fundamental elements of a collaborative business
process environment. For this wide-spread enterprise
FACILITATING BUSINESS PROCESS MANAGEMENT WITH HARMONIZED MESSAGING
31
application integration (EAI) and/or business to
business (B2B) integration to become a reality, we
need common architectures and open standards to
support it. B2B protocols attempt to establish a
common language between businesses, so that
collaborations (which occur between two business
partners) can take place without the need for pair-
wise negotiation of integration. Such protocols are
message centric by definition, describing the formal
message exchange necessary for an interaction to
take place between two business partners. B2B
protocols have been an active area of research
(Bussler, 2002) with two of the predominant
solutions in this area being RosettaNet
www.rosettanet.org and ebXML www.ebxml.org.
An alterative area of active research for enabling
automated inter-business interaction, and facilitating
system integration is obviously web service
technology (www.webservices.org). Web service
technology’s potential in the area of integration and
interoperation has generated great interest, with
initiatives from leading software vendors such as
Hewlett-Packard, IBM, Microsoft, SAP, Oracle and
Sun Microsystems. Web services are seen as a
means of integrating applications, promoting
interoperability and facilitating process management
over decentralized environments. The loose coupling
and dynamic binding characteristics of web services
are the main justifications towards achieving the
above.
The web service architecture is described by a
Web Services Stack (Kreger, 2001), however the
most appropriate stack structure remains a debated
issue, with a number of alternative architectures
offered by various consortiums and leading vendors.
Despite this disagreement, moves have been made
towards standardization, with a general consensus
existing concerning the underlying protocols
necessary in the architecture such as the Web
Services Definition Language (WSDL) Universal
Discovery Description (UDDI) and Simple Object
Access Protocol (SOAP). WSDL, UDDI and SOAP
however, are not alone enough to facilitate complex
and meaningful interactions with and between web
services, which would allow private and public
processes to harness the full potential of this
technology. Currently, many organizations are
attempting to address this problem, with proposals
intended to extend the basic web service
functionality primarily at the level which is often
referred to as the orchestration or choreography
layer of the web services stack (Uldell, 2002). These
extensions are aimed at capturing more meaningful
semantics than simply service invocations, enabling
the modelling and implementation of business
processes in the web service context. Prominent
initiatives in this area include WSCI, and
BPEL4WS. In addition, the importance of this area
is being recognized by emerging products (see e.g.
Collaxa http://www.collaxa.com/home.index.jsp).
An essential component of the next generation of
distributed architectures is message oriented
middleware (MOM). MOM provides the basic
means for target applications to communicate in a
distributed environment. Messaging middleware
however is not a new technology.
The past decade's move from client/server to
Web applications has intensified the need to move
information in real-time between disparate systems
and in a more controllable manner. In response to
these new developments, a set of Web-native
asynchronous messaging technologies has emerged
to take over where their legacy predecessors fall
short. These include products based on standard
implementations such as the Java Messaging Service
(JMS) or those that span multiple standards and
platforms.
In its new role, MOM has gained increasing
deployment and has already delivered great benefits
for communication between disparate systems, and
as a grass roots component of the web services
stack. In spite of the move from propriety networks
to open standards, the fundamental functionality of
MOM has not changed substantially. Looking at
currently available solutions, we see that the focus of
MOM has been primarily to deliver Security
(authorization, digital signatures, non-repudiation);
Reliability and Serializability (guaranteed delivery
in the proper order); and Scalability (high volume
and speed). The technology is driven by mainly two
dispatch models.
One is point to point, where message exchange
takes place between a sender and one recipient. This
is often based on queuing methods, such as the
IBM’s WebSphere MQ series (http://www-
3.ibm.com/software/ts/mqseries/). A second dispatch
model is publish-subscribe, which is used for
content dissemination to multiple recipients or
subscribers. Some essential enhancements to basic
messaging technology have been proposed, for
example in content-based routing which provides a
dynamic model, using the contents of the message to
filter messages to appropriate subscribers, see e.g.
Elvin (Arnold & Segall, 1997), Gryphon (Strom et
al, 1998), READY (Gruber et al, 1999).
3 HARMONIZED MESSAGING
Our vision of a new integration platform that would
provide universal sub-process connectivity has roots
in principles of messaging systems. The messaging
features that are imperative to the success of private
ICEIS 2004 - DATABASES AND INFORMATION SYSTEMS INTEGRATION
32
and public process communication in the web
context are clearly lacking in current messaging
technologies (see section 2). We aim to extend and
integrate messaging paradigms and use them as key
enabling technology for business process
management.
We believe that the next generation of messaging
technology will extend current ability to
communicate between partners, individual users, and
autonomous, private and often automated business
processes, in a web-centric environment. The
provision of a level of harmonization to multiple
messages often originating from different sources
will form a single custom definable backbone of
newly formed message streams. Such a technology
would present a new and simple way of enterprise
application integration/communication with
substantial degree of outsourcing capabilities, B2B
connectivity and collaborative business process
management. We call this next generation of
messaging: “Harmonized Messaging Technology”
(HMT).
This research problem, as any integration
problem where heterogeneous sources provide
components, is very challenging. Any solutions
offered must not only deal with data integration, but
also structure of hidden sub-processes, providing
interfaces to external partners without violating
privacy or security rules and at the same time
offering new functionality to all involved.
Even shallow inspection of the problem indicates
some serious difficulty. To better position this
complex problem, we base our framework on a set
of assumptions that define the scope of the problem
addressed in this paper.
Our first assumption is that business process
activities are mostly automated as is typical of B2B
environments and web service based architectures.
Our second assumption is that we are aware
about the existence of the components. The issue of
dynamic search and discovery of services is beyond
the scope of this paper.
Under these assumptions and as further
motivation for HMT consider a simple scenario
where multiple business partners are engaged in a
common process. A merchant organization places
orders to two separate manufacturers. Order delivery
by shipment partner needs to be synchronized within
and between the two orders. That is, shipment is to
take place not only when the entire quantity of one
order has arrived, but is to wait for the arrival of the
second order items as well. Orders and shipment
requests can be seen as electronic messages routed
through a messaging middleware. However, current
messaging functionality (publish/subscribe, point-to-
point) does not directly meet such advanced, yet
obvious requirements.
WFMSs provide an effective means of
coordinating business activities with well-defined
dependency relations (sequence, choice, fork etc).
We can use underlying coordination principles of
WFMSs to satisfy coordinative communication
requirements. Such an approach is being explored in
web service orchestration standards like BPEL4WS.
However, workflow systems do not possess effective
means to deal with collaborative form of message
communication.
Figure 2: Coordinative and Collaborative Message
Communication Approaches
The difference between coordinative and
collaborative messaging requirements is depicted in
Figure 2. In coordinative messaging paradigms the
order of message communication between
participants is defined using workflow like
constructs. In collaborative communication
paradigm the exchange of messages between
participants is depicted by linking them up with
communication channels. We propose to merge
coordinative and collaborative messaging paradigms
to effectively satisfy and manage a wide variety of
complex business process requirements. We believe
that this merger will serve the essential requirements
of current business process management systems.
4 ASPECTS OF HARMONIZED
MESSAGING
In this section we will establish the need and
motivation behind harmonized messaging by
presenting a number of cases where specialized
messaging functions are required. These cases are
intended to present a definition of what is meant by
harmonization. Some of these cases can be
(partially) met by existing messaging and workflow
solutions. However, it will become clear that
achieving a combined and extended functionality,
within a single technology, is the requirement of
current business interactions, and the objective of
harmonized messaging.
There are several aspects of messaging which
impact on, and define the scope for message
harmonization. We identify below seven aspects of
FACILITATING BUSINESS PROCESS MANAGEMENT WITH HARMONIZED MESSAGING
33
harmonized messaging, as a list of our minimum
requirements. However, there is no restriction on
extending this list, if business semantics warrant.
The power of the proposed technology lies in
providing a generic specification mechanism for the
rules and constraints which describe these
interactions.
Coordination
Messages often represent a step in a business
transaction or process. Coordinating the flow of
messages can take the form of most, if not all,
activity coordination structures in workflow/process
management. HMT can facilitate coordination
through multi-step complex routing specifications.
For example:
Wait for message from A and B to arrive before
sending to C.
Temporal
Temporal constraints represent a critical aspect
of business events. Time driven messages may
depend on absolute time e.g. 2.00 PM on Friday, as
well as relative time e.g. every 4 hours. Example of
time driven messaging can be:
Keep collecting messages from A and B until a
specific time and then send them to C.
Wait to send message to B until 3 hours after
receiving message from A.
Correlation
Messages from a single (or even multiple)
senders may be linked in terms of the content they
carry. Correlation can include associating or relating
a new message with a previously received message,
for example:
Associating or relating a new message with a
previously received message, for example
multiple items of a single purchase order.
Invalidating a previously received message.
Batching
The need for batching messages is clear from the
above. Batching or grouping may be required due to
message coordination, correlation or time
dependencies. The definition of the batch may thus
encompass many properties, for example:
Deliver all messages on a given topic from a
given sender at a given time, rather than one a
time as they arrive to the message server.
Filtering
This is essentially sending messages to interested
parties based on message contents (content based
routing). However, advanced filtering may be
required, which takes into consideration a
combination of conditions such as content, time,
sender and others. For example
Send a message to either B or C depending on
contextual condition.
Transformation
Message transformation may be required for
conformance to formatting restrictions, or for
ensuring that recipients are sent relevant data only.
For example
Extract essential data on date/time for a shipment
order and send a FYI message to the customer
Composition
The is a very powerful aspect of harmonized
messaging and is also illustrated further in Figure 3.
Composition basically entails extraction of relevant
data from one or more incoming messages and
composing together a system generated message.
For example
Extract relevant data from A, B and C
respectively and compose message D
Obviously the above functions are to be provided
over and above traditional messaging functions like
queuing and publishing/subscribing. Furthermore, it
is important to note that coordination requirements
are but a part of the overall set of requirements.
Thus, where typical workflow modelling constructs
such as sequence (multi-step), and synchronization
may be applicable, they cannot satisfy the larger
scope of requirements necessary for harmonized
messages. Interestingly, workflow constructs can
then be considered as a special case. A language to
support the specification of harmonization
requirements must additionally at least provide time
related, content dependent and existential conditions.
Considerations into the expressability and
limitations of such a language, is a major research
challenge, and remains an open question at this time.
5 TECHNOLOGY FRAMEWORK
The aspects above identify extensions to various
aspects of messaging. In the overall solution, these
aspects will be manifested through ‘Harmonization
Rules’. The harmonization rules can be defined as a
ICEIS 2004 - DATABASES AND INFORMATION SYSTEMS INTEGRATION
34
conjunction of a number of different requirements as
represented by the classes above. Clearly, multiple
rules originating from multiple independent parties
may carry some semantic or executable conflicts.
Ways to identify them prior to deployment must be a
part of the overall HMT solution.
Below we will introduce concepts that are
fundamental to the harmonized messaging, and
building blocks for the technology framework:
Collaboration Space
The most fundamental concept in HMT is that of
a Collaboration Space. The concept of a
collaboration space is similar to a database space,
where users, privileges, data and methods may be
defined. In HMT, the collaboration space will
similarly contain information on three key aspects:
Participants specify the parties involved in a
specific message interaction definition.
Rules and constraints model the harmonization
requirements using the specification language.
Message Templates define the structure to which
Messages being exchanged must conform to.
Clearly, at any given time there would be several
messages of one or more defined message template
type being exchanged by multiple participants
within a collaboration space. We call these message
objects. In simple terms, message objects that arrive
in the system may or may not trigger predefined
rules. If and when a rule evaluates to true,
subsequent (system generated) messages are
composed and dispatched. Figure 3 illustrates the
concept of message harmonization for Composition
of messages as given in the previous section. Note
that not all aspects of harmonized messaging can be
graphically shown, as they may involve expressions
with content and time. Thus the real power of the
technology resides in the specification of complex
rules that capture the behaviour of business
interactions.
Figure 3: Message Harmonization
in a Collaboration Space
In order to manage and harmonize message
objects as discussed above, there needs to be a
Harmonized Messaging Management System
(HMMS). The architecture of an HMMS is
obviously a highly specialized and complex issue,
and is beyond the scope of this paper. However, we
present below a brief description of its essential
components.
Interaction Modeler
The interaction modeller provides a toolset to
establish collaboration spaces, identify the
associated participants and message templates, and
in particular to model rules and constraints needed
by the collaboration space to support exchange of
messages. For the latter to effectively take place, the
interaction modeller must be equipped with a
language to express the conditions that govern the
harmonization requirements, which as mentioned
above will range from basic messaging models such
as queuing, publishing and subscribing, to typical
coordination structures as found in workflow
models, to complex expressions for correlation and
batching, the ability to understand expressions with
time and content, and the ability to transform and
create new messages.
Harmonization Engine
The Harmonization Engine is the core driving
force for the system supporting essential
functionality. This engine is primarily responsible
for managing the collaboration spaces defined
within the HMMS. Minimal features of the engine
will include: Access to a persistent storage facility
(HMT databases identified below); Management of
concurrent users building message streams;
Exception handler dealing with unexpected
behaviours; and Transactionability in order to offer
guarantee of completeness of execution
HMT Databases
The HMT framework will be supported by a
number of underlying databases essential for the
persistent storage and data management of various
aspects. These consist of:
Message Store - Message store allows reliable
and persistent of messages. A relational DBMS
can serve the purpose. The messages need to be
stored in the message store while in transition
from one participant to another and/or awaiting
harmonization rules to be triggered.
Participants Repository - To store information
about participants, processes and other objects
FACILITATING BUSINESS PROCESS MANAGEMENT WITH HARMONIZED MESSAGING
35
that need to exchange messages. It will also store
participant profiles (including at least
registration information, privileges, and
requirements).
Rules and Constraints - The harmonization
engine needs rules and constraints within a
collaboration space to effectively manage and
route the messages. The rules and constraints
repository maintains this information both for
design time and run-time.
Message Catalogue – Similar to a system
catalogue in a DBMS, the message catalog stores
template definitions for message objects.
System Log – Will be required to record all
system events to provide reliability and
transactionability.
HMT Gateway
The messaging gateway provides interfaces to
participants to register and connect to the
infrastructure and to send messages to and receive
messages from the collaboration space. A
dispatcher sub-component will evaluate
identification and routing information to correctly
position the messages within the collaboration
spaces.
6 CONCLUSIONS
HMT is intended to provide a platform for cross
organizational process interactions in a web-centric
environment. HMT is not aimed at invoking
applications or monitoring people (it is not a
workflow management system). We have primarily
presented a vision for this next generation of
messaging technology aimed at facilitating complex
business process interactions, typically found in
current e-business environments.
Currently, there is substantial interest in the
industry from vendors, standards bodies, as well as
research communities in this immensely important
area. The HMT differs from these approaches since
it builds upon message interactions as its core
building block. It offers to extend the simple
messaging approaches by adding additional process-
oriented extensions. The key contribution of this
approach is to effectively merge message-oriented
and process-oriented approaches for achieving both
inter and intra enterprise application integration. We
believe HMT can also play a key rule in web
services based enterprise application architectures.
HMT holds many interesting and challenging
research questions. We hope that the open questions
identified in this paper will also motivate other
researchers working in this area, to pursue solutions
to these questions.
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