FLEXIBLE REALIZATION OF BUSINESS PROCESSES USING
EXISTING SERVICES
Jelena Zdravkovic
Deptartment of Computer Sciences,University of Gävle and Royal Institute of Technology,
Martin Henkel
Department of Sydtem of Computer Sciences, Stockholm University and Royal Institute of Technology,
Keywords: Business processes, Executable processes, Service coordination, Flexibility.
Abstract: When realizing executable business process models, in most situations process specifications collide with
specific properties of existing services. In this paper we propose an approach for relaxation of the business
process specification to enable flexible integration between the process and existing services. The approach
is based on the notion of visibility, which allows a categorized relaxation of the process specification by not
requiring every process state to be distinguished after the process is realised with existing services. The
categories of visibility presented in this paper are applied by indicating flexible elements in the process
design phase. The presented approach stimulates the alignment between business processes and existing
services, facilitating a larger scale of transparent process realisations.
1 INTRODUCTION
Cross-enterprise e-collaboration requires that both
business activities and their supporting systems are
coordinated. From the business perspective, business
activities must be designed to cope with
requirements from all involved actors; for example
an e-business solution might need to deal with both
companies and private persons. The business
activities, the involved actors, and the information
the business need to control, are commonly
described by using the notion of a business process.
From the system perspective, business activities
must be supported by technology dependant system
services. These services need to be coordinated in
order to support the business process. The
coordination of services can be achieved by using
executable process description languages such as
BPEL4WS (BEA, 2003). As well as handling
business documents, the system services must cope
with additional details, for example, with message
format transformations and differences in
communication protocols. Due to the added
technical details we denote a process that
coordinates system services as a technical process.
A business process thus deals with pure business
concepts, while a technical process additionally
deals with the technical environment (protocols,
software products, etc.) that are required to provide
system support for the business.
It is paramount that a business process and its
corresponding technical process are designed such
that the technical process can represent the possible
states in the business process. It means that the
technical process must be aligned with the business
process. An effect of this alignment is that changes
made to the business process might affect the
technical process and vice versa.
An increasingly important characteristic of
executable processes that span across organizations
is flexibility. Constructing flexible business and
technical processes means that they can
accommodate changing business requirements,
without a major redesign. A problem with respect to
flexibility is that large organizations rely on legacy
systems for their core business; thus the technical
foundation is fixed rather than flexible. This means
that changes in the business requirements that affect
the technical process can be difficult to implement.
One solution to the problem is simply to avoid
business process designs that break the alignment
165
Zdravkovic J. and Henkel M. (2006).
FLEXIBLE REALIZATION OF BUSINESS PROCESSES USING EXISTING SERVICES.
In Proceedings of the Eighth International Conference on Enterprise Information Systems - ISAS, pages 165-172
DOI: 10.5220/0002444401650172
Copyright
c
SciTePress
with current support systems. However, this is far
from ideal since it would let the legacy systems
govern the business development; also, it is
infeasible for the business process designers to keep
track of all system limitations. Another solution,
which we propose in this paper, is to let the business
designer govern the quality of alignment between
the business and technical process.
Existing proposals on how to introduce
flexibility in process specifications can be classified
into two categories. Firstly, some authors suggest
making the process specification more abstract. By
raising the abstraction level the process loses details,
but at the same time captures a wider range of
behaviour. Examples of constructs that raise the
abstraction level are the use of ad-hoc sub-processes
(Heinl, 1999), activity inheritance (Aalst, 1999),
(Ribó, 2001) and patterns of flexibility (Sadiq,
2001). The second approach to process flexibility is
to introduce constructs that are tailored to handle
complex behaviour. These constructs are commonly
“cross-cutting”, i.e. they control behaviour on a set
of activities or an entire process. Examples of such
constructs are Event-Condition-Action (ECA) rules
(Joeris, 1999), process parameterization (Aalst,
1999) and the use of profiles to describe complex
error handling (Chopra, 2004). The approach
presented in this paper belongs to the first category -
the notion of visibility levels is a construct that
enables the business process designer to construct
processes that are less specified, and thus more
abstract. However, our approach differs in two ways.
Firstly, we introduce the notion of process visibility.
This enables us to augment an existing process
specification without changing its activities or flow
constructs. Secondly, we specifically target the case
where a process needs to fit on top of existing
technical foundations. Thus our approach is to keep
the alignment of two processes, business and
technical, flexible.
The paper is structured as follows. Section 2
illustrates a business process and shows how its
realization as a technical process is influenced by
existing services. Section 3 introduces the notion of
process visibility and categorizes it into three levels.
In Section 4, using a structured process design
framework, we define the rules for how to determine
the levels of visibility to align a business process
with its technical realization. Section 5 explains how
to apply the proposed notion during design and
implementation of business processes. Finally,
Section 6 concludes the paper.
2 EXAMPLE CASE
An example of a business process and its realization
as a technical process is shown in Figure 1. The
model illustrates a process developed under the
Serviam project (Serviam, 2005) to investigate
capabilities of the SEB bank (a North European
financial group) to integrate and coordinate its ERP
systems in the form of Web services. The business
process in Figure 1(a) depicts an excerpt of the
process used to supply customers with various types
of furniture, using Itea (Itea, 2005), a virtual sale
portal. The model is expressed in the Business
Process Modelling Notation (White, 2004). The
BPMN is used to visually model a process
management, which might further be converted to a
process language (such as BPEL4WS).
Upon receiving an order request, Itea retrieves
the customer contact and the customer’s order
history and then verifies the order amount and
details. After the order is processed by a supplier, if
the furniture is available, the customer’s account is
debited for the amount of the purchase. The order
confirmation is then sent to the customer.
The corresponding technical process, Figure
1(b), is based on existing services, provided by
Itea’s internal Order system and by its partners (the
bank - SEB and the furniture manufacturers – Mio or
its partners). Compared to the business process, the
technical process must adhere to capabilities of
existing services:
The customer contact and the order history are
retrieved with a single activity, because the
needed information is provided by a single
service.
The execution order of verification of the order
details and amount is not visible, because these
activities correspond to a single service.
Processing of an order and debiting of customer
account are managed as an atomic (two-phase
commit) transaction (AT), because the
corresponding services do not support
compensations needed for a long-running
transaction (LRT).
Order confirmation is sent by a single activity,
because it is implemented as a single service,
which encloses use of e-mail and fax protocols.
The example shows the impact that existing services
might have on the realization of a business process.
It is obvious that due to particular properties of the
services (granularity, task ordering, transactional
properties, etc.), the technical process cannot capture
all states the business process passes through.
ICEIS 2006 - INFORMATION SYSTEMS ANALYSIS AND SPECIFICATION
166
In the next section we define conditions under
which a technical process might be considered as
aligned with a business process, and how those
conditions may be relaxed to increase abilities for
the alignment.
3 LEVELS OF VISIBILITY FOR
BUSINESS PROCESSES
A technical process is a realization of a business
process by the use of existing services. When
designing processes, different aspects are to be
considered. In our previous work (Henkel, 2004), we
have, based on the workflow-modelling studies
(Jablonski, 1998) and (Rausch-Scott, 1997), defined
a framework containing five main aspects that
constitute process design: functional, behavioural,
organizational, informational and transactional.
When designing business and technical processes,
each of the five aspects must be regarded. In
(Zdravkovic, 2005), we argued that the basic
criterion for a technical process to realize a business
process is that
a technical process must be designed to trace all
states of a business process, where the content of a
single process state comprises the statuses of all five
design aspects.
In reality, specific properties of existing services
often collide with detailed specifications of business
processes. It is therefore difficult to obtain a
technical process that strictly realizes a business
process specification. In the example case in Figure
1, the business process retrieves the customer
information with two activities “Get customer
contact” and “Get order history”, while in the
technical process the same information is obtained
from a single activity “Get customer information”;
this means that the technical process can not trace
the state between the two activities in the business
process. As another example, it might be that a set of
business process activities is governed by a long-
running transaction, while the corresponding
services might be managed only as an atomic
transaction (i.e. as a “black-box”). In both discussed
examples the business process cannot be realized
with the existing services because the required
business states are not captured in the technical
process.
a)
b)
Receive customer
request
Process
order
Debit customer
account
LRT
Customer
Send order
conf. b
y
email
Get customer
contact
Get order
histor
y
Send order
conf. b
y
fa
x
Supplier
Bank
Verify order
details
Calculate
order amount
Receive customer
request
Process
order
AT
Customer
Itea Order System
Mio/?
SEB
Verify
orde
Send order
confirmation
Itea order process
Debit customer
account
Get customer
information
Figure 1: Business process (a) and technical process (b), presented in the BPMN form (White, 2004).
FLEXIBLE REALIZATION OF BUSINESS PROCESSES USING EXISTING SERVICES
167
To enlarge abilities for realizations of business
processes, it is thus important to have a mean to
relax the realization requirements. A way to achieve
this is to distinguish the states in the business
process that must be visible in the technical process,
from those states that might be hidden in services
(Figure 2). The distinction is determined according
to:
A business process state must be visible in the
technical process if its content is used by the
business process environment, i.e. by internal and/or
external actors that interact with the process;
otherwise the state needs not to be visible.
Figure 2: States hidden in a service implementation.
For example, it might be important that a set of
business activities are executed in a predefined
order, but the business might not require visible
tracking of the run-time execution order. Not
requiring visible tracking allows the use of existing
services that hide the execution order of activities. In
this way a business process that was unrealizable, or
“incompatible” with existing services, becomes
realizable in a limited way. It might be also required
to support visibility of the process states for a group
of instances, while not for the others. Following this,
flexibility in design of a business process may be
discerned in three levels of visibility:
Loss-full visibility: the flexibility is chosen when
a set of states of the business process need not to
be captured, because the contents of those states
are not used by the process environment for any
of the process instances.
Constrained visibility: the flexibility is chosen
when a set of states of the business process need
not to be captured for particular process
instances, while they must be captured for the
other instances.
Lossless visibility: the flexibility is chosen when a
set of states of the business process must be
captured, because their contents are used by the
process environment for all process instances.
As it may be seen from the above categorization, the
loss-full visibility gives maximum flexibility for
realizing a business process, while the lossless
visibility gives minimum. The constrained visibility
is used when neither lossless nor loss-full visibility
might be applied – in that situation, the business
process states are set to be visible on the “case”
basis. Having in this way categorized concepts of
flexibility, allows the business process designer to
relax requirements for alignment of a business
process with its technical realization, by selecting
flexible process elements with an adequate level of
visibility.
4 REQUIREMENTS FOR
VISIBILITY IN PROCESS
DESIGN
Using the five-aspect design framework that we
have introduced in the previous section, in the
following, we define criteria for discerning the
levels of visibility for each of the design aspects.
Functional Aspect. The functional aspect
considers the activities that are to be executed in a
process. For each activity the functionality is
determined by three elements: the activity name
which describes the result to be achieved, exchanged
messages, and input and output constraints that form
pre-conditions and post-conditions. In a business
process, decomposition of activities is done
according to recognized business tasks. For instance,
the distinguished business concepts “verify order
amount” and “debit customer account” will be
administered by two distinct process activities.
Existing services might be designed to support
functionality required by a business process, but
without “notifying” the process about the
fulfillment. This is the case when the granularity of a
single service is designed such that the service
encompasses functionality of more than one
business activity. Thereby, the technical process is
not able to capture the states to distinguish the
exchanged messages or results or pre- and post-
conditions of each of the business activities.
For instance, in Figure 1, we may see that in the
business process the customer information is
retrieved with two activities - “Get customer
contact” and “Get order history”, because from the
business perspective those information concepts are
handled by distinct business tasks. Since the two
messages defined in the business process are
exchanged internally, following the rule defined in
Technical process Services
Business process
ICEIS 2006 - INFORMATION SYSTEMS ANALYSIS AND SPECIFICATION
168
the previous section, the minimal level of visibility
is determined by the requirements of the internal
actors governing the customer information. If none
of them need to distinguish the customer contact
from the order history, the visibility of the two
activities might be set to the loss-full. Thereby, the
technical process, exchanging the customer
information with a single service, will become
aligned with the business process. If, however, the
messages has to be separately available for all
customers (lossless visibility), or at least for some
instances (constrained visibility), alignment between
the two processes is not reachable without
redesigning existing services.
In general, the requirement for visibility of the
functional aspect of a business process can be
determined by the business process designer by
applying the following guiding question:
Visibility of the functional aspect
Q Is it mandatory to capture the messages, the result,
or the pre- and post-conditions of a business
process activity, in the technical process?
A - No, because the business process environment
does not use (i.e. does not need to distinguish) any
of the three functional elements of the activity
(loss-full visibility, LFV)
- Yes, because the business process environment
uses at least one of the functional elements of the
activity (lossless visibility, LLV).
- Yes, for some process instances (constrained
visibility, CRV).
Behavioural Aspect. The behavioural aspect
depicts process control flow, i.e. when an activity is
to be executed in relation to others. For specification
of dependencies and coordination rules among
activities, process specifications rely on a set of
basic control flow constructs: ordering (sequence,
parallel execution), and conditional branching
(OR/XOR). In a business process the use of the
control flow constructs is determined by identifying
flow dependencies among business activities.
When realizing a business process, existing
services are used to implement the required flow
constructs. The granularity of these services might
be such that they encompass some execution order
as well as branching conditions, i.e. existing services
might govern it internally. For instance, examining
visibility of branching conditions, it may be seen
that in the business process in Figure 1(a) the order
confirmation is sent using one of the two protocols:
e-mail or fax. The selection of the protocols is
chosen based on the customer profile data. However,
as Itea does not oblige to inform customers on the
protocol used for sending the order confirmation, it
means that the visibility of the selected condition is
not required in the business process (i.e. might be set
to loss-full). As the implementation is provided by a
single service that includes the selection of a
protocol, the corresponding technical process, not
supporting the condition selection, becomes aligned
with the original process.
Visibility of the behavioural aspect
Q Is it mandatory to capture the ordering of a set of
activities in a business process?
Is it mandatory to capture the conditions of a
branch in a business process?
A No - LFV; Yes - LLV; for some instances - CRV.
Informational Aspect The informational aspect
of a process concerns the concepts needed for
representing process internal data and the data that
the process exchanges with the environment in the
form of messages (and documents). In a business
process the documents are modelled to capture
relevant information on business concepts such as
customers, orders, products, etc.
Even thought existing systems are designed to
support the required business information, the
information structures of services (i.e. input and
output documents) might not provide the contents
required by a business process.
Visibility of the information concepts of the
business process in Figure 1 cannot be determined
directly from the given BPMN model, as this
requires comparison of the message documents in
both processes. By doing that, as an example, we
find that the business process requires for
international customers the address structure in the
“Get customer contact” message, to contain two
addresses – one that is the customer’s registered
address (in the bank), and the other used for the
product delivery; the latter address is necessary to
have to calculate the overall order amount. However,
the delivery address is not needed for domestic
customers, because for those customers delivery
expenses are fixed (same). This means that the
visibility of the address might be set to constrained.
The requirement for visibility of the informational
aspect of a business process is generally determined
by using the following rule:
Visibility of the informational aspect
Q Is it mandatory to capture the content of an
information concept defined in a business process?
A No - LFV; Yes - LLV; for some instances - CRV.
Transactional Aspect The transactional aspect
governs consistent execution of a set of activities
(implemented by services). Process transactions
FLEXIBLE REALIZATION OF BUSINESS PROCESSES USING EXISTING SERVICES
169
comply with two different models. The atomic
transaction (AT) model (Bernstein, 1987) is used to
control a set of shorter services such that the
outcome is visible only when all services within a
transaction finish successfully. The long-running
transaction (LRT) model (Garcia-Molina, 1991)
rules more durable services, where each service
enforces a globally visible outcome independently of
the other services. This means that the models differ
in the exposure of the intermediate transactional
states. Thus, when designing transactions in a
business process, the selection of the model is
determined upon necessity on visibility of internal
transactional states.
Concerning the example from Figure 1(a),
business process activities “Process order” and
“Debit customer account” are designed as long-
running, in order to capture the supplier information
on availability of the furniture. However, as Itea still
does not offer the ability for a partial delivery (might
be used when the supplier informs on partial order
availability), the current business requirements
would be satisfied even without ability for using the
internal transactional results. This means that the
visibility of the business process transaction might
be set to loss-full. The technical process, supporting
the atomic model, would then be aligned with the
originally designed process.
The requirement for visibility of the transactional
aspect of a business process is generally determined
by using the following rule:
Visibility of the transactional aspect
Q Is it mandatory to capture the internal states of a
transaction in a business process?
A No - LFV; Yes - LLV; for some instances - CRV.
Organizational Aspect. The organizational
aspect concerns the distribution and control of
responsibility for executing activities. When
designing a business process the responsibilities are
allocated to business roles, such as “Bank”,
“Supplier”, etc.
When the business process is realized with
existing services, the responsibilities are transferred
to the parties that host services. Those parties may
perform the services themselves or they may
forward them to third parties. This transformation
may prevent the business process to “see” what
parties actually executed these services.
Examining the example in Figure 1, it may be
seen that the business process defines the Supplier
business role as being responsible for the activity
“Process order”. Itea has a long-term contract with
Mio, for the main supplier. From the contract
perspective, Itea does not mind if the furniture is
actually supplied by a third-party. This means that
the visibility of the organizational aspect for the
“Process order” activity might be set to loss-full.
Knowing that for some styles of furniture, the Mio
service forwards requests to its partner-suppliers,
(not visible to the technical process), the loss-full
visibility of the Supplier role enables the alignment
between the two processes.
Following the outlined, the requirement for
visibility of the organizational aspect of a business
process can be determined by using the following
rule:
Visibility of the organizational aspect
Q Is it mandatory to capture the information on what
business party executed a business process activity?
A No - LFV; Yes - LLV; for some instances - CRV.
5 APPLYING VISIBILITY
LEVELS
The use of the visibility levels affects both the
design and implementation of executable processes.
During design, the business designer applies the
levels by labelling business process elements
(activities, control flow, transactions, information
concepts, roles, etc.) with a desired level of
visibility. The technical process designer later on
uses these labels in order to implement the process
on top of existing services.
In this section we outline how the business- and
the technical- process designer use visibility levels.
Our intention is to provide an overview of how the
visibility levels affect the design process rather than
providing a complete method description.
The business process designer starts with
creating an “ordinary” business process model. This
is done by analyzing the business requirements;
neither the forthcoming visibility labelling, nor
technical concerns affect this model.
ICEIS 2006 - INFORMATION SYSTEMS ANALYSIS AND SPECIFICATION
170
As the next step, the business process designer
must change mindset in order to apply the visibility
levels. The visibility levels should reflect the need of
the environment to monitor the process execution at
runtime. As stated in Section 3, the process
environment consists of external and internal actors
that interact with the process. External actors are
commonly depicted in the business process model,
for example “Customer”, “Supplier” and “Bank” in
Figure 1(a). Internal actors are those within the
organization that are interested in monitoring the
process states. In order to view the process from the
internal viewpoint it might be helpful for the
designer to take the viewpoint of a process
supervisor. A process supervisor is responsible for
the execution of the process, that is the completion
of the process cases (Aalst, 2002). The reason to
take a process environmental view is to be able to
pinpoint the process elements that do not need to be
visible at runtime even thought these elements are
being executed. Guided by the questions from
Section 4, the designer applies the loss-full visibility
(LFV), or constrained visibility (CRV) labels to the
elements that do not need full visibility during
execution. Elements from all five process aspects are
labelled as following:
Functional – Activities and sub-processes
Behavioural – Branching and ordering
constructs
Informational – Information concepts
Transactional – Transactions boundaries
Organizational – Roles/organizations that are
participating in the process
Figure 3(a) depicts a labelled excerpt from the
beginning of the example case in Section 2. In this
case, the designer decides to label the first activity as
LFV, because the start and completion of the activity
“Get customer contact” does not have to be
monitored at runtime. The “Get order history”
activity is labelled as CRV because there is a desire
to get a notification whenever a “gold” customer
with an annual order history exceeding 5000€ places
an order. In this case, a note is placed beside the
CRV label to indicate for which instances lossless
visibility is needed.
At the end, the business process designer gets a
business process with elements labelled with the
desired visibility, from a process supervisor’s point
of view.
When the business process is labelled, it is up to
the technical process designer to construct an
executable process that adheres to the business
process design and that utilizes existing services.
Ideally, the business process can be implemented as-
is, with no changes applied. However, existing
services might not allow the implementation of the
lossless visibility for all constructs in the process.
For example, certain information concepts might be
hidden inside old legacy systems, and therefore be
unavailable to the technical process. Since the
business designer has labelled the elements with
their desired run-time visibility, the technical
process designer has obtained flexibility for
designing the technical process. Unmarked (loss-less
visibility) elements must still be implemented as-is,
but the elements labelled with LFV or CRV can be
implemented by applying “black-boxing” and
selective black-boxing:
Black-boxing can be applied when an element
is labeled with the loss-full visibility (LFV).
For example, information concepts and
behavioral branching can be hidden inside
legacy services.
Selective black-boxing can be applied where
lossless visibility is needed for some instances;
this is applicable for elements marked as CRV
(constrained visible).
Figure 3(b) depicts how black-boxing is applied
to two activities - they are simply implemented as
one in the technical process. Note that applying
Get customer
contact
Get order
histor
y
LFV
CFV
LLV for instances
with ”gold”
customers
Get customer
contact &
history
Get customer
contact
Get order
histor
y
Get customer
contact & hist
a
b
c
Gold customers
Figure 3: Labelling business process activities with levels of visibility (a); implementing the business process activities i
n
the technical process according to existing services (b and c).
FLEXIBLE REALIZATION OF BUSINESS PROCESSES USING EXISTING SERVICES
171
black-boxing in this way violates the business
process design, since some instances (those with
gold customers) need full visibility. However, if
both the activities in figure 3(a) would be labelled as
LFV, this would be a valid construct.
Figure 3(c) depicts how selective black-boxing is
applied. In this case two branches are introduced,
one that handles “gold” customers and one that
handles the other customers. The branches are
implemented by using different services that
represent two existing solutions.
The above basic steps outline how the business-
and the technical- process designer apply the
visibility levels to achieve alignment between
business and technical processes. It must be stated
that the goal of the technical designer is to keep
maximum visibility (LLV); the lower levels of
visibility are considered when it is of great cost to
change existing services. The benefit of striving
towards high visibility in the technical realization is
to keep important flow logic inside the technical
process, rather than scattering it across services.
6 CONCLUSION
In this paper, we have proposed an approach for
flexible alignment between business processes and
their technical realizations in the environment of
existing services. The approach is based on the
notion of visibility. The use of the notion of
visibility enables a process designer to distinguish
states in the business process that must be captured
(i.e. visible) in the final technical process. By
studying the notion, we have defined three levels of
visibility, where each determines a degree of process
flexibility: loss-full, constrained and lossless. Based
on a process description framework grounded on
five main design aspects, we have then defined a set
of rules for discerning minimal level of visibility
that might be set when designing business processes.
Our concept of flexibility enables a relaxation of
requirements for alignment of a business process
with its technical process, by selecting flexible
process elements with an adequate level of visibility.
In this way defined, the concept of visibility
facilitates a process realization where existing
services might implement a process without
enabling the business to monitor every single
process state. From the evolution perspective, the
notion of visibility gives ability to the business
process designer to assess the design of a process to
abstract (i.e. loose) the parts that need not to be
captured in the final technical process; for the
technical process designer, the notion of visibility
guides needed refinements of existing services.
REFERENCES
Aalst W.M.P., Hee, K., 2002. Workflow Management
Models, Methods and Systems. The MIT Press.
Aalst W.M.P., 1999. Flexible Workflow Management
Systems: An Approach Based on Generic Process
Models. In DEXA’99. LNCS 1677, pp. 186-195.
BEA, IBM, Microsoft, SAP and Siebel, 2003. Business
Process Execution Language for Web Services. In
http://www.ibm.com/developerworks/library/ws-bpel
Bernstein, P., Hadzilacos, V., Goodman, N., 1987.
Concurrency Control and Recovery in Database
Systems. Addison-Wesley.
Chopra A., Singh M., 2004. Commitments for Flexible
Business Processes, In AAMAS'04. IEEE Computer
Society 2004.
Garcia-Molina, H., 1991. Modelling Long-Running
Activities as Sagas. IEEE Data Engineering Bulletin,
Vol. 14/1, 1991, 14–18.
Heinl P., Horn S., Jablonski S., Neeb J., Stein K., Teschke
M., 1999. A Comprehensive Approach to Flexibility
in Workflow Management Systems. In WACC ’99.
ACM WACC proceedings, pp. 79-88.
Henkel, M., Zdravkovic, J., Johannesson, P., 2004.
Service-Based Processes – Design for Business and
Technology. In ICSOC’04. ACM Press, 2004.
Itea portal, 2005. In http://itea.dsv.su.se
Jablonski, S., 1998. A Software Architecture for
Workflow Management Systems. In DEXA’98. IEEE
Computer Society, 1998, 739-744.
Joeris, G., and Herzog O., 1999. Towards Flexible and
High-Level Modeling and Enacting of Processes, In
CAiSE'99. LNCS 1626, pp. 88-102.
Rausch-Scott, S., 1997. TriGSflow – Workflow
Management Based on Object-Oriented Database
Systems and Extended Transaction Mechanisms. In
PhD Thesis, University at Linz.
Ribó J.M., Franch X., 2001. Building Expressive and Flex.
Process Models Using UML-Based Approach. In
EWSPT’01. LNCS 2077, pp. 152–172.
Sadiq, Sh., Sadiq, W., Orlowska, M., 2001. Pockets of
Flexibility in Workflow Specifications. In ER2001.
LNCS 2224, pp. 513-526.
SERVIAM Project , 2005. In http://www.serviam.se
White, S., 2004. Business Process Modeling Notation 1.0,
(BPMN). In http://www.bpmi.org. Business
Management Initiative.
Zdravkovic J., Henkel M., Johannesson P., 2005. Moving
from Business to Technology with Service-Based
Processes. IEEE Magazine of Internet Computing,
Vol. 9/3, May/June 2005.
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