=Paper=
{{Paper
|id=None
|storemode=property
|title=YAWL4Industry: Reflections on using YAWL for Industry Projects
|pdfUrl=https://ceur-ws.org/Vol-982/YAWL2013-Paper04.pdf
|volume=Vol-982
|dblpUrl=https://dblp.org/rec/conf/yawl/WynnOA13
}}
==YAWL4Industry: Reflections on using YAWL for Industry Projects==
https://ceur-ws.org/Vol-982/YAWL2013-Paper04.pdf
YAWL4Industry: Reflections on using YAWL for
Industry Projects
M. T. Wynn, C. Ouyang, and M. Adams
Queensland University of Technology, Brisbane, Australia.
{m.wynn,c.ouyang,mj.adams}@qut.edu.au
Abstract. The Yet Another Workflow Language (YAWL) language and
environment has been used to prototype, verify, execute and analyse
business processes in a wide variety of industrial domains, such as tele-
phony, construction, supply chain, insurance services, medical environ-
ments, personnel management and the creative arts. These engagements
offer the YAWL researcher community a great opportunity to validate
our research findings within an industry setting, as well as discovery of
possible enhancements from the end user perspective. This paper de-
scribes three such industry projects, discusses why YAWL was chosen
and how it was used in each, and reflects on the insights gained along
the way.
Keywords: YAWL, Case Studies, Industry Experience, Deployment,
Uptake
1 Introduction
The YAWL language and environment is well-known in the areas of research, for
topics such as verification, configuration, exception handling, visualisation, risk-
awareness and cost-awareness, and teaching, having been taught in the courses
of at least 36 universities across 20 countries. Originally intended as a reference
implementation of workflow patterns, the open-source YAWL environment pro-
vides an ideal testbed for novel research ideas. In the decade since the YAWL
language was first developed, we, as YAWL researchers, have modelled numerous
YAWL processes that reflect various scenarios in different application domains
– ranging from structured transactional processes (e.g., insurance claim, travel
booking, conference paper review processes) to manual and flexible processes
(e.g., scheduling of medical operations). In most cases, our main focus is on
evaluating a specific research artefact. Hence, we abstract from things that are
less relevant to our purpose, for example, in a particular research project we
might not spend much time on the development of intuitive user interfaces or we
might not fully integrate a YAWL process with external systems. In addition,
there may be limited stakeholder involvement in terms of user acceptance testing
of the results of particular projects.
In recent years, a number of organisations have initiated YAWL deployments
to prototype, verify and execute their business processes. This paper summaries
26
the insights gained from our involvement in such projects in three different do-
mains: construction, the creative arts, and telephony, whereby we demonstrated
how YAWL can be used to model and automate processes within a particular do-
main in collaboration with domain experts who were actively involved in require-
ments analysis and design, process modelling, implementation and acceptance
testing of the resulting system.
2 Case Studies
Each of the selected case studies was undertaken in close collaboration with
domain experts, and each case delivered a YAWL environment tailored to or-
ganisational needs. The prototype process for construction is used for demon-
stration purposes, the YAWL4Film system was trialled and deployed in the real
film production setting, and the system developed by first:utility was for ongoing
production. A brief overview of the three case studies is given below.
2.1 Construction
Construction processes are complex, involving planning of activities from de-
sign to build, coordination between various teams (e.g. designers, contractors,
builders, engineers, inspectors), and intensive use of building materials, equip-
ment, and tools. In recent years, off-site manufacture (OSM) has been recognized
as an effective way to reduce cost at the procurement stage of construction.
Currently, construction management practices are predominantly manual and
founded on the project manager’s experience. This case study aimed to demon-
strate how business process automation techniques can assist in capturing OSM
requirements within a construction project.
A collection of process models (using BPMN notation) that represent the
generic construction value chain was developed [2]. Based on the input from
the domain experts from the Australian construction industry, key activities, re-
sources, data and stakeholders involved in each activity within the construction
value chain were identified. A prototype YAWL application was then developed
to showcase the ability of workflow systems to support and coordinate OSM-
related process activities [7] and demonstrated to stakeholders. The YAWL en-
vironment was chosen due to its ability to coordinate multiple parties involved in
a construction project as well as its comprehensive support for rapid prototyping.
2.2 YAWL4Film
Processes in the field of screen business are characterised with high demands for
creativity and flexibility. A typical process is one that supports film production,
an important phase that encompasses when the majority of cast and crew are
contracted and the majority of the equipment and resources are utilised. A film
production is a highly manual process that requires handling large amounts
of heterogeneous data on a daily basis and coordinating many geographically
27
distributed stakeholders. The benefits offered by applying automation to such a
process are twofold: it may ultimately reduce the production costs by minimising
errors and delays; and by saving time otherwise spent in costly and tedious
procedural tasks, the production team can focus more on creative activities thus
increasing the quality of the final product [4].
The development of a prototype system, namely YAWL4Film demonstrated
that the benefits stated above can be brought to the field of screen business
through the application of workflow technologies [3]. The process model captures
the control flow (see Figure 1), data and resource perspectives of a standard film
production process. An important feature of YAWL4Film lies in the modelling of
intensive data associated with the process, which had led to the development of
customised user forms to support templates used in professional film making, and
implemented using JSP, XSLT, and related Web technologies. A trial application
of the system was conducted during two student productions at the Australian
Film, Television and Radio School in 2007, which was followed in 2008 by real
deployment of the system in the production of a medium-budget feature film by
Porchlight, an independent film production company.
2.3 first:utility
First Utility Ltd (first:utility) is an independent utilities group based in the
United Kingdom. Amongst other interests, it provides a variety of competitive
telephony services to its customers, through the leasing of wholesale telephony
lines from British Telecom (BT), which it on-sells to customers at competi-
tive rates [1]. BT provides a Service Providers Gateway (SPG) through which
providers can access BT’s internal systems. The gateway may be accessed via a
browser based session, which is slow and open to input and transaction errors, or
via an API, which is suitable for high volumes of order processing. Of particular
interest is the use of the SPG to place an order to have a customer’s telephone
line transferred from BT to the provider. However, processing an order can in-
volve a number of potential errors, or exceptions, which require suitable recovery
and retry processing to ensure an order can be successfully completed.
An implementation of the YAWL environment was chosen by first:utility
to provide workflow support for both back-office automation and the human-
controlled work activities of their Customer Relationship Management (CRM)
systems. For back-end automation such as the line transfer order process, YAWL
provided a number of advantages. One was the ease with which a custom ser-
vice could be developed to interface with the SPG. Another was the various
mechanisms available to build-in exception detection and recovery into long-
lived processes by design. For CRM workflows, first:utility developed their own
worklist extension that generates web-based forms using runtime attributes and
XSLT transformations.
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3 Insights
3.1 The YAWL Language
For all three case studies, the YAWL language was found to be capable of sup-
porting all the required control flow behaviours for the processes, making use
of various complex control flow constructs including multiple instances, cancel-
lation, advanced synchronisation, composite and timer tasks [6]. For example,
Figure 1 shows the YAWL model of the film production process. Using an OR-
join together with loop constructs, we were able to specify precisely the process
logic in a less ‘crowded’ way. The graphical notation of YAWL was found to
be easily understood by designers, domain experts and stakeholders. For the
resource perspective, most tasks were modelled using the role-based allocation
mechanism with additional constraints making use of separation of duties, retain
familiar and pile execution resource patterns where appropriate. For the data
perspective, the support for user-defined complex XML datatypes made the task
of defining the data requirements straightforward.
Fig. 1. The YAWL model of a film production process [3].
3.2 The YAWL Framework
Because the YAWL environment is built on a Service Oriented Architecture, it
allows the central workflow engine to be readily extended through the devel-
opment of value-added services [5]. A number of services are included in each
YAWL core deployment, including those that extend the environment to include
29
the resource perspective, flexibility and exception handling, inter-process inter-
operability, resource and activity scheduling, cost-awareness, document sharing,
email services and simulation. The environment can be further extended by or-
ganisations developing their own custom services to perform specific activities,
such as the first:utility SPG interfacing service described earlier. In addition, by
introducing a small number of extensions to the environment, first:utility was
able to suspend and resume cases and manually raise compensation processes to
manage exceptions.
Another advantage of the YAWL environment that made it attractive to
first:utility was its scalability. With many thousands of concurrent process in-
stances, first:utility was able to scale the environment across a number of servers,
running several engine instances in parallel. They also created a ‘quarantine’
server, where processes that had experienced a failure could be ported and closely
examined to determine the root cause of the problem. Once rectified, the process
could be moved out of quarantine and back into the production environment.
Fig. 2. An example dynamic form (with extended attributes) created for the construc-
tion workflow case study.
3.3 User Customisations
Although the auto-generated web forms provided by the YAWL environment
are very useful for rapid prototyping purposes, we found that most end users
prefer customised web forms in the final product. The YAWL environment sup-
ports this customisation requirement in two ways. First, by using the extended
attributes feature, the colour, font and label names of auto-generated forms can
be customised at design time. This enables a YAWL consultant to quickly change
the look-and-feel of auto-generated forms.
30
Fig. 3. An example custom form created for the construction workflow case study.
Figure 2 illustrates a screen shot of a dynamic form created for the con-
struction workflow case study where the colour theme of the SBEnrc centre was
utilised. Second, by allowing a custom web form to be associated with a YAWL
task, a YAWL consultant is free to create custom forms from scratch and also
add new functionalities to the form. In Figure 3, the user interface for the “Ap-
point Project Manager” task for the construction process is shown (where three
additional functionalities were added - “Edit Score”, “Appoint” and “Print”). A
significant amount of time was spent to develop intuitive and easy-to-use user
interfaces in all three case studies. This customisation capability is found to be
an essential feature in improving usability and user acceptance of the YAWL
environment within an industry setting.
4 Conclusion
Based on our experience in applying YAWL within industry settings, the key
strengths of the YAWL environment can be summarised as follows.
– The YAWL language is expressive and supports all necessary constructs for
industry projects.
– The YAWL environment is an excellent tool for rapid prototyping.
– The extensibility of the open-source YAWL environment makes it possible
for organisations to develop their own customised services.
– The YAWL environment enables the development of customised user inter-
faces allowing organisations to ensure consistent look and feel across their
applications.
Some of the key lessons learned from our experience to develop and deploy
a YAWL system are as follows. First, although it is quick to develop a working
31
YAWL prototype, a significant amount of project time is spent on developing cus-
tomised user interfaces and custom services in most cases. Secondly, to develop
a YAWL system that makes appropriate use of complex control flow constructs
supported by the YAWL environment, a YAWL consultant should be well versed
in the semantics of the YAWL language. The same is true for the data and the
resource perspectives supported by the YAWL environment. Finally, a YAWL
consultant should take into account the fact that the YAWL environment is
an open-source research environment with functionalities being added by many
participants over time and that some of these functionalities may not have been
extensively tested before their release.
Work currently in progress, including a redesign of the YAWL Editor and
an automated system update facility, may encourage more widespread adoption
of the YAWL language and environment in industry. More extensive training
materials have also been identified by designers and domain experts as desirable.
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