BUSINESS PROCESSES MODELLING
IN SMEs USING PETRI NETS
Vesna Bosilj-Vuksic
Department for Business Computing,
University of Zagreb, Faculty of Economics
Simon J.E. Taylor
Centre for Applied Simulation Modelling,
Department of Information Systems and Computing
Brunel University, Uxbridge, Middx, UB8 3PH, UK
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Presentation Overview
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Small and medium-sized enterprises (SMEs) in the global
marketplace
Business process reengineering (BPR)
The critical role of information technology (IT) in BPR
The Internet and online business models
BPR and Petri nets
DES-nets
An example of simple retail processes using DES-nets
Conclusions
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Small and medium-sized enterprises
(SMEs) in the global marketplace
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Small and medium enterprises (SMEs) are extremely important
to many countries.
According to the European SME observatory, 99,8% of
European organisations in 1999 were SMEs, representing
almost 66% of total employment [The European Observatory
for SME, 1999].
E-commerce is a unique opportunity for SME’s to extend their
capabilities and to facilitate business growth.
Though SMEs have identified the benefits of IT and e-business,
they are lagging behind in adopting new business models
because of a number of barriers: unavailable investment
capital, lack of resources, lack of knowledge and long-term ecommerce strategy.
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Business process reengineering
(BPR)
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In order to survive in highly competitive business
environments, companies have to continuously change their
business processes.
BPR means analysing and altering the business processes of
the organization as a whole.
Many leading organisations have conducted BPR, but the rate
of success of re-engineering projects is less than 50%
[Hammer and Champy, 1993].
Some of the frequently mentioned problems related to BPR
include the inability to accurately predict the outcome of a
radical change and the inability to recognise the dynamic
nature of the processes.
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The critical role of information
technology (IT) in BPR
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The Internet plays a significant role in BPR projects.
The efficiency of BPR depends upon the innovative stage of
the information system and its use of modern IT.
IT has the strongest impact on standardization or elimination
of process variations. Because of that informatization cannot
start before the work process improvement has been
successfully implemented.
IT contributes heavily as facilitator to the process of
reengineering.
IT contributes in the reengineering process as enabler to
master the new process in the most effective way.
The Internet technology is also an easily available and lowcost strategy for BPR implementation.
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The Internet and online business models
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The Internet is altering the ways in which businesses operate
and interact with customers, suppliers and partners.
The Internet enables companies of all sizes to develop new
online business models.
E-business includes fast changes of business environment and
demands quick and flexible adoption of businesses.
E-business is not only enabling the redesign of internal
organisational processes, but is extended into interorganisational processes.
An enhancement geared to include inter-organisational
processes is called Business Network Redesign (BNR).
BNR identifies the inter-organisational processes to redesign
and extends the strengths of BPR to the networking among
business partners. The Internet enables companies of all sizes
to develop new online business models
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BPR and Petri nets
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Petri nets are a method which enables graphical modelling of
system behaviour simultaneously enabling introduction of
mathematical formal rules for system behaviour definition
[Petri, 1962; Törn, 1985; Oberweis and Sönger, 1992].
A whole variety of Petri nets extensions have been developed,
each being specific and each having certain extensions.
Simulation modeling has a great potential for assessment of
the possible benefits as it enables quantitative estimations of
influence of the redesigned process on system performances.
Petri nets could be used in BPR projects because of the
following characteristics: simplicity, representation power
comprising concurrency, synchronisation and resource
sharing, strong ability of their mathematical analysis and
application of software tools.
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DES-nets
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DES-nets are built around coloured Petri nets [Ceric, 1995]
because they are by far the most developed type of high-level
Petri nets.
DES-nets incorporate some simulation graphs extensions such
as arcs with weight, timed transitions and inhibitor arcs.
DES-nets incorporate also additional extensions, such as three
types of decision rules: priority rules, probability rules and
conditional rules.
DES-nets use the following elements of coloured Petri nets:
token colours, token colours sets, place with inscription
(coloured place), arc with inscription (coloured arc) and
transition with a guard.
Discrete Event Simulation nets or DES-nets are used in this
paper in order to demonstrate the suitability of Petri Nets for
business process modelling.
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An example of simple retail processes
using DES-nets
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In this research an example of modelling simple retail
processes using DES-nets is provided.
The increasingly complex conditions of retail business create
the need for radical advances in the retail process of SMEs.
Starting with the objectives of modernising the retail business
process in SMEs it is possible to re-define scenarios of existing
retail processes.
The re-engineered retail process can be divided into three
phases, which can be defined as the sales scenario, the
purchasing scenario, and the stocking scenario.
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An example of simple retail
processes using DES-nets
Figure 1:
DES-net of sales and
purshasing scenario
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An example of simple retail
processes using DES-nets
Figure 2:
DES-net of the
stocking scenario
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Conclusions
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The Advantages of Computer Supported Retail
Business Process Model
Data and information about sales are collected at Electronic
Point of Sale (EPOS).
The processed data is the basis for an analysis of sales,
accounting and financial operations.
The information system supports the logistics related
operations of receiving and stocking merchandise in the store
and inventory control.
EPOS includes a module for automatic electronic payment
(Electronic Fund Transfer).
The implementation of proposed model could be the first step
toward e-commerce implementation in SMEs.
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Conclusions
Suitability of DES-nets for Business Process Modelling
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Presented characteristics of Petri nets accomplish the typical
objectives of BPR to increase service level, reduce total
process cycle time and waiting time reduce activity, resources
and inventory costs, and increase throughput.
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Petri nets are "cost-effective" methods of exploring "what-if"
scenarios quickly and finding a problem solution or providing
better problem understanding.
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They are supported by a number of software tools that enable
graphical representation of the system by the executable
models.
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There is also a possibility for automatic translation of Petri
nets into IDEF diagrams which are widely used in business
process modelling, especially in information system modelling.
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Conclusions
Limitations of Petri Nets
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Lack of standardization (a large and growing number of Petri
nets)
Rather complicated to understand for the members of BPR
projects not specialized in computing and simulation
Not suitable for modelling of processes’ data
Could be more appropriate to use IDEF diagrams during the
preliminary phases of business process modeling projects due
to their simplicity and understandability
In later phases, when “TO BE” models are developed, IDEF
diagrams could be transformed into Petri nets which adds
formal semantic to the models.
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Conclusions
BPR Framework
The adoption of presented methodology by SMEs could help to
avoid a number of major BPR mistakes:
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lack of understanding of the opportunities available to SMEs
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lack of employees' skills and knowledge of BPR methods and
tools
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high investment costs related to business process
identification, analysis and modelling
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difficulty in capturing existing processes in a structured way
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inability to accurately predict the outcome of a radical change
and to recognise the dynamic nature of the processes
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Conclusions
Future work
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A "prototype" of the "standard retail business process model"
was developed.
The benefits of the developed model should be explored.
Future research will be oriented toward general retail
business process model for guiding SMEs performance
improvement.
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