AN INTER-ORGANIZATIONAL PEER-TO-PEER WORKFLOW
MANAGEMENT SYSTEM
P2P based Virtual Organization Concept
A. Aldeeb, K. Crockett and M. J. Stanton
Department of Computing and Mathmatics
Manchester Metropolitan University, Manchester, M1 5GD, U.K.
Keywords: Inter-organizational workflow management system, Intra-organizational workflow management system,
Peer-to-Peer, Virtual organization, Exception handling, workflow adaptability, Case-based reasoning.
Abstract: Current inter-organizational cooperation technologies and approaches do not adequately support cross-
organizational workflow. These approaches concentrate on automating the public workflow in isolation
from the internal workflow management systems inside the cooperating organization. Integrating Peer-to-
peer (P2P) and workflow technology enables virtual enterprises to dynamically form and dismantle
partnerships between organizations workflow management systems. In addition, P2P workflow based
systems support various forms of workflow interoperability e. g capacity sharing, chained execution,
subcontracting, case transfer, loosely coupled and public to private approach. This paper describes a novel
peer-to-peer inter-organizational workflow management framework (P2P inter-org WFMS), which includes
workflow advertisement, workflow interconnection, and workflow cooperation. Each organization acts as a
workflow peer (WFP) in a virtual enterprise. Sun Microsystems’s JXTA P2P networking environment is
used for prototype implementation. XPDL (XML Process Definition Languages) is used for process
definition as it offers portability between different Process Design tools. The internal WFMS in each
organization is being implemented using TIBCO Business Studio ™.
1 INTRODUCTION
Workflow is the automation of business processes,
in which tasks, documents and information are
passed from one participant to another for action,
according to a set of procedural rules. A workflow
management system (WFMS) is the software tool
for defining, executing and monitoring the
workflow. Current workflow management systems
focus on the automation of business processes within
the boundaries of a single organization (Liu, et al,
2005). However, as a result of the current increase in
cooperation across organizational boundaries, there
is an increased need for inter-organizational
workflow management systems (inter-org WFMS).
Traditional WFMS are based on the following
requirements (Riempp and Nastansky, 1997): (1) all
actors, routing paths and storage locations in the
workflow are known. (2) Legal, organizational and
security aspects are under control of a single
management. (3) Hardware, operating systems and
workflow management applications are mostly
homogeneous. In contrast, for inter-org WFMS, the
actors, routing, and storage locations are not
established in advance. In addition, the organizations
involved have different legal and organizational
systems, different security aspects, and
heterogeneous hardware, operating systems and
workflow applications.
The cooperation between organizations to
execute a shared process can take the form of a
“virtual organization”. Riempp (1998) defines the
virtual organization (VO) as a temporary coalition of
several, legally independent organizations, with the
purpose of offering a jointly manufactured product
or jointly provided service to customer who perceive
the VO as a singular entity. Virtual organizations
require flexible, on-the-fly alignment of business
partners; in other words, adaptive workflow
capabilities (Buhler and Vidal, 2005).
Recently, researchers have shown an increased
interest in the integration of P2P and workflow
technology to improve efficiency (Berry and
Muhlberger, 2002; Coon, 2002; Yan, 2006; Fakas
85
Aldeeb A., Crockett K. and J. Stanton M. (2008).
AN INTER-ORGANIZATIONAL PEER-TO-PEER WORKFLOW MANAGEMENT SYSTEM - P2P based Virtual Organization Concept.
In Proceedings of the Tenth International Conference on Enterprise Information Systems - SAIC, pages 85-92
DOI: 10.5220/0001682600850092
Copyright
c
SciTePress
and Karakostas, 2005; Aldeeb et al, 2007). P2P is an
innovative technology that is both flexible and
scalable and provides communication autonomy.
Furthermore, P2P WFMSs are proposed to avoid the
bottleneck and the central point of faults caused by
client/server workflow systems and to improve
scalability, system openness and support
incompletely specified processes. The aim of the
research presented in this paper is to extend the
current P2P WFMSs to an inter-org WFMSs. A
novel peer-to-peer inter-org WFMS framework
which overcomes the limitation of the current inter-
org WFMSs is proposed. This paper is organized as
follows, in section 2, some existing inter-
organizational cooperation technologies and
workflow approaches are presented along with a
discussion of intra-organizational P2P WFMSs. The
proposed inter-organizational P2P WFMS with its
architecture is introduced in section 3. Prototype
implementation is described in section 4, and section
5 concludes the paper with discussion of future
work.
2 RELATED WORK
2.1 Inter-organizational Cooperation
Technologies
Electronic Data Interchange (EDI) is traditionally
used in e-commerce to exchange standardised
structured data between cooperating organizations
(Aalst, 2000a). A Value Added Network (VAN) is
used for EDI transmission for security and additional
features. Despite the benefits of using VAN, it is
complex, has multiple interpretations, and requires
significant technical expertise to deploy. For these
reasons, e-commerce is moving to Web-Based EDI,
which allows organizations to interact with their
partners using the Web. However, EDI solutions are
concentrating on the data transaction and there is no
explicit inter-organizational workflow features (e.g.
allocating and re-allocating task to the participants,
coordination and routing and monitoring).
Integrating EDI technology with workflow is
required for efficient e-commerce.
Web services are now the standard for e-business
and requires several XML-based technologies to
transport and to transform data between programs
and databases (Newcomer, 2002), including WSDL,
SOAP and UDDI. Web services represent loosely
coupled interactions, which are well suited to
integrating disparate software domains and bridging
incompatible technologies. Web services are
simpler than EDI and it is easier to exchange
electronic documents via the internet. Perrin et al.
(2003) implement the middleware between partners
in a VO as web services to provide dynamic and
flexible integration between them. The electronic
business XML (ebXML) is another technology to
enable business-to-business (B2B) transactions by
exchanging a standard XML-based business
messages (Newcomer, 2002). The ebXML
messaging specification is based on SOAP, with
attachments. It does not use WSDL and UDDI but
does add several qualities of service, such as
security, guaranteed messaging mechanism. ebXML
architecture extends basic Web services concepts
and they overlap in many areas. In general, ebXML
specifications can be seen as enhancements to Web
services. These cooperation technologies are tools
for inter-organizational cooperation without explicit
inter-organizational workflow mechanism. Extra
effort is needed to add important workflow aspects,
such as autonomous actions, deliberatively
cooperative behaviour, messages routing to
participants, and querying other participants for
status information of a workflow instance.
2.2 Inter-organizational Workflow
Approaches
Aalst and Weske (2001) proposed a Public-To-
Private approach to inter-organizational workflows
based on a notion of inheritance. This approach
consists of three steps: (1) create a common
understanding of the inter-organizational workflow
by specifying a shared public workflow, (2) partition
the public workflow over the organizations involved,
and (3) for each organization, create a private
workflow which is a subclass of the respective part
of the public workflow.
CrossFlow (Grefen et al, 2001) is an approach
aimed at providing high-level support for workflows
in dynamically formed virtual organizations. In
CrossFlow, partially defined contracts are used by
service providers to advertise their services, and by
service consumers to search for services. As such,
the contract is the basis for dynamic partnerships. A
contract specification language is needed to form the
matchmaking process and to generate the contract
enactment infrastructure dynamically.
The Workflow-based Internet Service (WISE)
(Lazcano, G. et al., 2000) is aimed at designing, and
implementing software tools for business to business
e-commerce over the Internet. The designed
software platform includes four modules: process
definition module, process enactment module,
ICEIS 2008 - International Conference on Enterprise Information Systems
86
monitoring and analysis module, and coordination
and communication module.
Chebbi et al. (2006) propose a view-based
approach to dynamic inter-organizational workflow
cooperation. This approach allows for partial
visibility of workflows and their resource in the
cooperating organizations. Varying degrees of
visibility of workflows enable organizations to retain
required levels of privacy and security of internal
workflows.
2.3 Intra-organizational P2P Workflow
Management Systems
In P2P WFMS (Fakas and Karakostas, 2005; Yan,
2006; Aldeeb et al, 2007), peers join “virtual
communities” according to their capabilities and
discover each other using the services provided by
an open P2P network. The coordination is
performed by notification messages exchanged
between peers. Two functions are conducted by P2P
WFMS: A Build-time function, which includes
workflow process modelling, storing process
definitions and distributing the process to workflow
peers, and a Run-time function, which includes
workflow instantiation and task coordination. P2P
network provides services that include advertisement
services, group services, peer services, pipe services,
and discovery services. In P2P WFMS, a workflow
peer (WFP) is a software component that can reside
on any machine on the P2P network enabling direct
communication with other workflow peers to enact
the workflow process. The internal structure of the
WFP consists of user, task, and flow components. It
also maintains four data repositories – a peer
repository, a resource and tools repository, a task
repository and a process repository. Each WFP is
associated with a workflow participant and each
performs a part of the workflow. Once the task is
completed, the WFP informs its successor and the
next task of the process is executed. Process co-
ordination is achieved by the exchange of both
information and control messages between peers.
The few proposed P2P WFMS in the literature
are designed for intra-organisational workflow
scenarios (Yan, 2006; Fakas and Karakostas, 2005;
Aldeeb et al, 2007). Despite the advantages of
applying P2P for intra-organisational WFMS, it is
unlikely that all business circumstances in one
organization would require enforcement of a peer to
peer workflow where no one has the overall control.
In other words, P2P intra-organisational workflow is
not a general solution and will be based on the
requirements and the internal structure of the
organization. However, given the discussion of
Inter-organisational WFMS in section 2.2, P2P
WFMS would seem a good general solution for
inter-org WFMS where no central control exist and
the partners are autonomous workflow actors, who
can join and leave VO at any time. In addition, the
participating organizations can implement internal
centralized client/server or decentralized P2P
WFMS based on their requirements.
A novel inter-org WFMS is introduced in the
next section. This system will play the role of
business process integration and management
(BPIM) which involves linking both intra-
organizational and inter-inter-organizational
workflow together to achieve the desired business
process. The inter-organizational system is based on
a P2P platform while the internal WFMSs for the
organizations involved can be decentralized P2P
WFMS or classical centralized client/server WFMS.
3 INTER-ORG P2P WFMS
For inter-organizational business processes, the
execution of workflow may generate a very high
load. This load can affect workflow servers and the
underlying communication network (Bauer et al.,
2003). To improve scalability and efficiency,
integrating P2P technology with inter-organizational
workflow is proposed. In inter-org WFMS, there is
cooperation between information systems that
belong to autonomous organizations; they can at any
time join or leave the shared process. This can be
achieved by applying P2P workflow for inter-
organizational WFMSs where P2P WFMS can be a
promising solution. Each organization involved in
the inter-org workflow will be represented by a
workflow peer (WFP) and these peers will form a
P2P virtual organization. The P2P open network will
be the gateway between the various WFMS of the
cooperating organizations. The goal is to utilize P2P
technology to support organizations involved in a
shared cooperative workflow across organizational
boundaries. A public workflow model is agreed
between different organizations which collaborate as
peers, while keeping their internal private workflow
within their boundaries.
Figure 1 shows an overview of the proposed P2P
inter-organizational workflow management system
using a simple case study. In the case study, three
organizations customer, supplier and manufacturer
are involved in managing a workflow process. This
includes; workflow advertisement, workflow
interconnection, and workflow cooperation. Each
AN INTER-ORGANIZATIONAL PEER-TO-PEER WORKFLOW MANAGEMENT SYSTEM - P2P based Virtual
Organization Concept
87
organization acts as a workflow peer (WFP) in this
process. The three workflow peers discover each
other by the advertisement service provided by the
P2P network infrastructure. Communication
between peers is achieved using structured
messages. The detailed mechanism and the
functionalities of the peer-to-peer workflow system
can be found in (Yan, 2006; Fakas and Karakostas,
2005; Aldeeb et al, 2007). As shown in Figure 1, the
customer organization is implementing an intra-org
P2P WFMS. When the customer participates in
forming the VO, its inter-org WFP will be part of
two P2P groups. The first group is an internal group
within the boundary of the organization while the
second group is the external VO group. However,
the other two partners in the VO implement a client-
server internal WFMS. Existing workflow
management systems can plug into the P2P VO if
they can fulfil the following two conditions: First,
the WFMS can call an external application (which is
the virtual organization WFP in this case). Second,
the WFMS allows external applications to invoke
any step within its workflow.
Figure 1: Inter-org P2P WFMS overview.
Figure 2 shows the sequence diagram for the inter-
org workflow. This includes three phases of
interactions. The first phase is WFP identification
where associated WFPs for customer, supplier, and
manufacturer publish their services and join
different groups of a specific product or service e.g.
(customers will form a group of customer of specific
product). Each WFP find a desired partner. Second
phase is the WFP interconnection; starting with
electronic negotiation and connection then a virtual
P2P organization is formed. The third phase is WFP
Figure 2: Inter-organizational P2P WFMS interaction
sequence diagram.
cooperation, instantiating a workflow instance and
coordination of tasks by message exchange between
peers. In addition, one of the cooperating workflow
peers in the virtual organization will play the role of
‘Exception Handling Peer (EHP)’. The function of
the EHP is handling the workflow exceptions and
applying an appropriate recovery policy. The
exception handling mechanism is described in
section 3.3.
3.1 Inter-org WFP Internal Structure
Figure 3 shows the high level internal structure of
the WFP. This peer consists of the following parts: a
user interface to create, deploy and monitor the
workflow, an enactment component which serves as
a workflow engine to enact the tasks associated to
this peer, a process repository to store the workflow,
and an exception handling unit. There are two
network interfaces: the first one is to send and
receive messages to and from other peers in the
virtual organization. The second interface to invoke
and exchange information with the internal WFMS.
Manufacturer
P2P Virtual
Organizatio
VO Peer
Intra-org
P2P
WFMS
Internal
WFMS
Internal
WFMS
Supplier Customer
VO Peer
VO Pee
r
Customer WF
Peer
Supplier WF
Peer
Manufacturer
WF Peer
P2P Advertisement
Service
Publish ()
Publish ()
Publish ()
Partner
Found ()
Partner
found
()
Partner
found ()
Negotiate ()
Negotiate ()
Ne
g
otiate
()
Connect ()
Connect ()
Connect () Connect ()
Request ()
Request ()
Response ()
Response ()
Delivery ()
Workflow
peers
identifica-
tion
Workflow
peers
interconn-
ection
Workflow
peers
cooperat-
ion
Ne
g
otiate
()
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3.2 Build-time and Run-time Function
of the System
Figure 3: Inter-org WFP Internal Structure.
Loosely coupled is a mechanism to model and
analyse inter-organizational workflow where each
partner takes care of a specified part of the process
(Aalst, 2000b). In this mechanism, the partners are
working independently but synchronization at
certain points is necessary to ensure the correct
execution of the whole process. The proposed
system can be considered as loosely coupled P2P
system. During build-time, the workflow peers in the
virtual organization model and define their parts in
the public workflow and the message structure is
agreed between them. At run-time the workflow
initiator peer is responsible for initiating a workflow
instance. The coordination of this workflow instance
will be achieved by notification messages exchange
between peers.
3.3 Adaptability and Exception
Handling
Workflow adaptability is the ability of the workflow
processes to react to exceptional circumstances
(Sadiq et al., 2005). So far, a little progress has been
reported in addressing exception handling in inter-
organizational business processes (Luo et al., 2003;
Reichert et al., 2003). Workflow exceptions in the
P2P WFMS can be classified to two types of
workflow exceptions: local workflow exception and
global workflow exception. Local workflow
exception affects the task of one workflow peer. The
workflow peer can handle this exception by applying
one of two possible self-recovery policies; forward
recovery or backward recovery. Forward recovery
policy is based on correcting and isolating the effect
of the exception and returning the workflow task to a
normal state so the normal operation can be
continued. In contrast, backward recovery policy is
based on restoring the workflow task to a consistent
state that occurred before the appearance of the
exception. If the local workflow exception can not
be handled within the affected workflow peer, it can
propagate to the other workflow peers leading to a
global workflow exception. This type of exceptions
will, of course, affect more than one workflow peer
and a coordinating node is required to deal with this
exception. In this research, the coordinating node is
the exception handling peer (EHP). The EHP can be
a dedicated peer in the VO or any other workflow
peer with an exception handling capabilities can play
this role in addition to its basic role. The EHP
captures exceptions from the workflow peers,
characterizes the exceptions and applies a recovery
policy. This mechanism is based on separating the
business logic and exception handling logic to make
it easy to keep track of both (Hagen and Alonso,
2000). Furthermore, this will facilitate the process of
verification and later modification of business and
exception handling logic. In addition, the EHP can
select an appropriate exception handler based on the
situation and according to prior knowledge.
In P2P WFMS as a distributed system, backward
recovery of one workflow peer of communicating
peers will often require other peers in the group to
be rolled back because of the interdependencies
caused by message communication. The result is a
cascade of rollbacks called the ‘domino effect’
(Miller and Tripathi, 2004). To avoid the domino
effect in the proposed P2P WFMS a conversation
scheme (Miller and Tripathi, 2004) is used. A P2P
conversation is formed by a group of workflow
peers affected by an exception, and a workflow peer
in the P2P conversation can only communicate with
workflow peers that are in the same conversation.
This can prevent the error propagation and limits the
domino effect. In exception handling mode, the EHP
coordinates the exception handling process in the
P2P conversation. The P2P conversation represents
an atomic action consisting of interactions in a group
of peers. After the effect of the exception is
contained and resolved, the P2P conversation will be
dissolved and the workflow peers will return to the
normal mode of the P2P WFMS.
The EHP is provided with a Case Based
Reasoning (CBR) unit to handle exceptions which
need to be managed in similar way, but may occur in
different instances. CBR (Watson, 1997) is an
artificial intelligent technique which can be defined
as the process of solving problems by using or
Use
r
Co
m
po
n
e
n
t
Process
Repositor
Associated Inter-org workflow participant
Send/Receive
Message
Enactment
Component
Public to private
if
Interaction with other
virtual or
anization WF
Exception
Handling
Module
Interaction with internal
WFMS
AN INTER-ORGANIZATIONAL PEER-TO-PEER WORKFLOW MANAGEMENT SYSTEM - P2P based Virtual
Organization Concept
89
adapting solutions to old similar problems. CBR can
be described by the CBR-cycle which comprises
four activities (Watson, 1999):
1- Retrieve similar cases to the problem
description
2- Reuse a solution suggested by a similar
case
3- Revise or adapt that solution to better fit
the new problem if required
4- Retain the new solution once it has been
confirmed or validated
CBR can add great value to the exception
handling in workflows as the CBR system collects
and stores cases; the WFMS becomes more resistant
because it has a large set of knowledge to handle
future exceptions (Cardoso et al., 2001). The nearest
neighbour technique is a widely used in CBR
(Hwang and Tang, 2004). The similarity between the
new exception (target) and previously stored
exceptions (source) is determined using the
following equation:
(1)
Where T is the target exception case; S is the
source exception case; i an individual exception
attribute from 1 to n; f a similarity function for
exception attribute i in exception cases T and S; and
w the importance weighting of exception attribute i.
In the VO, exception attributes, which are stored
as a case include: workflow instance number, status
of workflow instance, exception type, exception
description, time of creation, use counts, associated
workflow peer number, exception solution. The
nearest neighbour approach is applied by first
retrieving similar exceptions and then selecting the
nearest similar exception. The associated exception
handler is then applied. If the distance between cases
is greater than a set similarity threshold then a new
temporary case is established and a new exception
handler is created. Frequent appearance of certain
exceptions and the usage of their associated stored
cases may lead to creation of a new version of the
workflow schema and business process evolution.
4 PROTOTYPE
IMPLEMENTATION
Currently, the feasibility of the ideas presented in
this paper are being implemented, validated, and
tested using a proof-of-concept prototype. Current
progress on the prototype and a case study are
described in this section.
4.1 Workflow Specification Language
and Implementation Tools
Sun MicroSystem’s JXTA is the networking
environment for P2P while XPDL (XML Process
Definition Languages) is used for process definition
as it offers portability between different Process
Design tools. The internal WFMS in each
organization is being implemented using TIBCO
Business Studio™. TIBCO Business Studio™ is
selected because it supports several industry
standards, namely Business Process Modeling
Notation (BPMN) and XPDL. In addition, TIBCO
Business Studio™ provides two types of tasks; send
task and receive task. Send Tasks are used to send
messages to a system or person outside of the
Process (in this prototype send task is used to call
and instantiate the JXTA platform for the VO
workflow peer). Receive Tasks are used to wait for a
message from a system or person outside of the
Process (in this prototype receive task is used by the
VO workflow peer to invoke the internal WFMS).
4.2 Case Study
Figure 4 shows the case study used for the prototype
implementation in Petri-net representation. Three
organizations, namely a customer, a supplier and a
manufacturer, are involved in managing a workflow
process. A workflow instance starts at the customer
internal WFMS when a specific product is required.
The internal WFMS will send an external request for
this product to the workflow peer which represents
the customer in the VO. This request is an XML
message contains the order details (Order No,
product Name, Description and Quantity etc). The
customer workflow peer will initiate a public
workflow instance by sending the order to a selected
supplier workflow peer which in turn will select a
manufacturer workflow peer. A P2P VO is formed
to manage a public workflow instance (product
order). The status of this public workflow instance at
any time is available for all the VO peers because
every VO workflow peer is capable to query other
workflow peers for status information of workflow
instance. The sequence of these tasks and interaction
is shown in figure 4. Another scenario for the
prototype implementation will consider that the
customer has an internal P2P WFMS. In this case,
=),( STSimilarity
ii
n
i
i
wSTf ×
=
),(
1
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90
Figure 4: The prototype implementation and public-to-private workflow interaction.
JXTA P2P network is the infrastructure for both
customer internal P2P WFMS and The P2P VO. A
workflow peer in the internal customer WFMS will
be part of the VO peers as well. This workflow peer
will initiate a workflow instance for a specific
product and the order will be sent to the supplier
peer and manufacturer peer. The rest of the
workflow process is similar to the first scenario. In
this case study, the customer workflow peer in the
VO is provided with an exception handling
capabilities and will play the role of the EHP in
addition to its basic role. Ad-hoc changes will be
made in the running workflow instance to examine
the exception handling procedures mentioned in
section 3.3.
5 CONCLUSIONS AND FUTURE
WORK
Applying P2P technology for inter-organizational
workflow is the novelty of the ideas presented in this
paper. Inter-organizational P2P WFMS can be
considered as a business process integration and
management (BPIM) tool which facilitates linking
both intra-organizational and inter-inter-
organizational workflow together to conduct the
desired business process. In addition, P2P workflow
management systems can be a promising solution for
inter-organizational workflow because of the
autonomy that facilitates the partners which act as a
workflow peers in inter-organizational business
process. A P2P inter-organizational workflow
approach provides the mechanism for workflow
peers to do the following: discover other peers and
their services, publish their available services,
exchange data and control messages with other
peers, route messages to other peers , query peers for
status information related to a workflow instance,
and dynamically form and dismantle groups. The
P2P WFMS previously designed for intra-
organizational WFMS is being upgraded for inter-
organizational scenario using a prototype
implementation for a case study. The adaptability
and exception handling can be achieved by applying
workflow peer self-recovery policies, P2P
conversation, and the EHP concepts. The EHP
within the virtual organization will be responsible
for handling the exceptions in the P2P conversation.
This peer will acquire knowledge from previous
exceptions using case based reasoning. Evaluation of
the proposed system will be carried out and
comparison with other inter-org workflow
approaches.
Receive
Order
from
Internal
WFMS
Select
Su
pp
lie
r
Send Order
Receive
Invoice
Make
Pa
y
m
e
nt
Receive
Delivery
Date
N
otify
Internal
WFMS
Receive
Orde
r
Select
Manufacture
r
Send Order to
Manufacture
r
Send
Invoice
Receive
Pa
y
m
e
nt
Confirm
Deliver
y
Customer WF Peer Supplier WF Peer
Produce
O
r
der
Deliver
Orde
r
Manufacturer WF Peer
Customer Internal
WFMS
End
Start
External Task
R
eques
t
External Task
Res
p
onse
P2P Virtual Organization (VO) Intra-org WFMS
AN INTER-ORGANIZATIONAL PEER-TO-PEER WORKFLOW MANAGEMENT SYSTEM - P2P based Virtual
Organization Concept
91
Future work will include exception classification
in P2P inter-organizational workflow and calculation
of exception’s re-occurrence rate in the VO. This
will help to confirm the value of using CBR as a
methodology for exception handling in the system.
REFERENCES
Aalst, W.M.P. (2000a) Process-oriented Architecture for
Electronic Commerce and Inter-organizational
Workflow. Information Systems, 24, 8, pp. 639-671.
Aalst, W.M.P. (2000b) Loosely Coupled
Inter0rganizational Workflow: modelling and
analyzing workflows crossing organizational
boundaries. Information and Management, 37, issue 2,
pp. 67-75.
Aalst, W.M.P. and Weske, M. (2001) The P2P Approach
to inter-organizational Workflow. In the Proceeding of
the 13
th
International Conference on Advanced
Information Systems Engineering, pp. 140-156,
Springer-Verlag.
Aldeeb, A., Crockett, K. and Stanton, M. (2007) an
Adaptive P2P Workflow Management System. In
Proceedings of the 9
th
International Conference on
Enterprise Information Systems (ICEIS-2007),
Information Systems Analysis and Specification, pp.
428-433, Funchal, Portugal.
Bauer, T., Reichert, M. and Dadam, P. (2003) Intra-subnet
Load Balancing in Distributed Workflow Management
Systems. International Journal of Cooperative
Information Systems, Vol. 12, No. 3, pp. 295-323.
Berry, D. and Muhlberger, R. (2002) Peer-to-Peer
Information Systems. Technical Report, University of
Queensland, Australia.
Buhler, P. and Vidal, J. (2005) Towards Adaptive
Workflow Enactment Using Multiagent Systems.
Information Technology and Management 6,pp. 61-87.
Cardoso, J. et al. (2001) Survivability Architecture for
Workflow Management Systems. Technical Report,
University of Georgia, USA.
Chebbi, I., Dustar, S. and Tata, S. (2006) The View-based
Approach to Dynamic Inter-organizational Workflow
Cooperation. Data & Knowledge Engineering 56, pp.
139-173.
Coon, M. (2002) Peer-to-Peer Workflow collaboration:
White paper, viewed: 5/11/2006 http://www.proteus-
technologies.com/cmm/docs/P2P_Workflow_Whitepa
per.doc.
Fakas, G. and Karakostas, B. (2004) A peer to peer (P2P)
Architecture for Dynamic Workflow Management.
Information and Software Technology,46 pp 423-431.
Grefen, P. et al. (2001) Crossflow: Cross-organizational
workflow management for service outsourcing in
dynamic virtual enterprises, IEEE Data Engineering
Bulletin 24, pp. 52-57.
Hagen, C. and Alonso, G. (2000) Exception Handling in
Workflow Management Systems, IEEE Transaction
On Software Engineering, 26, no 10, pp. 943,958.
Hwang, S. and Tang, J. (2004) Consulting Past Exceptions
to Facilitate Workflow Exception Handling. Decision
Support Systems, 37, pp. 49-69.
Lazcano, G. et al. (2000) The Wise Approach to
Electronic Commerce, International Journal of
Computer Systems Science & Engineering 15, Special
issue on Flexible Workflow Technology Driving the
Networked Economy.
Liu, J. Zhang, S. and Hu, J. (2005) A Case Study of an
Inter-enterprise Workflow-support Supply Chain
Management System. Information & Management, 24,
pp. 441-454.
Luo Z. et al. (2003) Exception Handling for Conflict
Resolution in Cross-Organizational Workflows.
Distributed and Parallel Databases, 13, pp. 271-306.
Miller, R. and Tripathi, A. (2004) The Guardian Model
and Primitives for Exception Handling in Distributed
Systems. IEEE Transaction on Software Engineering,
30, pp. 1008-1022.
Newcomer, E. (2002) Understanding Web Services.
Pearson Education, Inc., Boston.
Perrin, O. et al. (2003) A Model to Support Collaborative
Work in Virtual Enterprises. Lecture Notes in
Computer Science, BPM, 2678, pp. 104-119, Springer.
Reichert, M., Rinderle, S. and Dadam, Peter (2003)
ADEPT Workflow Management System: Flexible
Support for Enterprise-Wide Business Processes.
W.M.P van der Aalst et al. (Eds.): Lecture Notes in
Computer Science, BPM, 2678, pp. 370-379, Springer.
Riempp, G. and Nastansky, L. (1997) Managing Business
Processes in Virtual Enterprises Interaction of
Distributed Workflow Management Systems. In the
Proceedings of IT-Vision, Virtual Enterprises &
Networked Solutions, New Perspectives on
Management, Communication and Information
Technology, ESTIEM, VISION Week, Paderborn.
Germany.
Riempp, G. (1998) Wide Area Workflow Management,
Creating Partnerships for the 21
st
Century. Springer,
London, UK.
Sadiq, S. Orlowska, M. and Sadiq, W. (2005)
Specification and Validation of Process Constraints
for Flexible Workflows. Information Systems, 30, pp.
349-378.
Watson, I. (1997) Applying Case-Based Reasoning:
Techniques for Enterprise Systems. Morgan Kaufmann
Publishers, San Francisco, USA.
Watson, I. (1999) Case-based reasoning is a methodology
not a technology. Knowledge-Based Systems, 12, pp.
303-308.
Yan, J., Yang, Y. and Raikundalia, G. (2006) SwinDew- A
p2p-Based Decentralized Workflow Management
System. IEEE Transactions on Systems, Man, and
Cybernetics, 36, No. 5 pp. 922-935.
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