MODEL-BASED FAILURE ANALYSIS OF BUSINESS PROCESS

Xiaocheng Ge, Richard F. Paige and John A. McDermid

Department of Computer Science, University of York, York, U.K.

Keywords:

Business process, Failure analysis, Health information system.

Abstract:

The success of most organisations are based on how well the organisation can engineer and execute their

business processes in order to better manage the extra value that these processes can provide. However,

business processes may fail to deliver the functions which are designed. In order to help the understanding

of how and why a business process may fail, we considered the techniques in system safety engineering

and integrated them with existing techniques of business process modelling and analysis. We proposed a

framework of business process failure analysis. The kernel of the framework is that we extended the workﬂow

net of a business process by modelling failures as coloured tokens and so that the failure behaviours of the

business process can be simulated. In addition, we developed a tool based on the codes of an open source

project to support the analysis. The applications of proposed technique have demonstrated that it is a powerful

and easy-to-use technique for the management of business processes in large complex enterprise systems.

1 INTRODUCTION

The concept of business process has received consid-

erable attention by the community of business admin-

istration as organisations have been seeking how they

do their business more efﬁciently.

And some organisations are process-centric, i.e,

the business of such organisations are usually divided

and managed according to their business processes.

The examples of such process-centric organisations

are banks and hospitals. Any failure in their business

processes will directly lead to a disaster to their busi-

ness. For example, considering a hospital discharge

system, a failure in the execution of the hospital dis-

charge process may cause troubles to both the patient

who is discharged from the hospital and the hospital

itself because the failure may lead to serious impacts

e.g, a delayed discharge, or re-hospitalisation, or even

death of patients. Thus, when (re)engineering a busi-

ness process, the managers and engineers who are in-

volved always have to answer following questions:

• Why can this process fail?

• How can this process fail?

And in most cases, the failure of a business process is

due to the failures of the activities in the process. So

the additional questions can be asked:

• How is a process effected by a failure of an indi-

vidual activity in the process?

• What is the most vulnerable activity in the pro-

cess?

• How can potential failures be eliminated or con-

trolled?

These questions cannot be answered without hav-

ing a clear understanding of the business process and

its environment.

In system engineering, a few techniques, e.g, Fail-

ure Mode and Effect Analysis (FMEA), have been

proposed and successful applied to analyse hazards

and failures in safety-critical systems. In this pa-

per, we propose a framework which integrates the

concepts and practices of FMEA especially process

FMEA from safety engineering domain with existing

technique of process modelling and analysis from the

domain of BPM so that the failure analysis and per-

formance analysis of a business process is bridged to-

gether.

The core of our framework is a model of faults

propagation in the business process, which is a Petri

net model with extension of colour, called Failure net.

388

Ge X., F. Paige R. and A. McDermid J..

MODEL-BASED FAILURE ANALYSIS OF BUSINESS PROCESS.

DOI: 10.5220/0003496203880391

In Proceedings of the 13th International Conference on Enterprise Information Systems (ICEIS-2011), pages 388-391

ISBN: 978-989-8425-55-3

 2011 SCITEPRESS (Science and Technology Publications, Lda.)

2 FRAMEWORK OF BUSINESS

PROCESS FAILURE ANALYSIS

2.1 Deﬁnition of Business Process

A business process, by its deﬁnition in (OMG, 2008),

is a collection of related, structured activities. The

speciﬁcation of a process deﬁnes the set of activities

as well as the procedure and conditions on when such

activities will be performed, i.e, in what order an ac-

tivity is executed and how. To emphasise that a busi-

ness process may have a hierarchical structure, here

we add a sentence to this deﬁnition that a business

process is composed of a set of activities linked to-

gether in order to interact, where each activity is an-

other process, etc; The recursion stops when an ac-

tivity is considered to be atomic: any further internal

structure cannot be discerned, or is not of interest and

can be ignored.

Failure is the term in our research to describe a

state or condition which does not meet a desirable

or intended objective, and is viewed as the opposite

of correctness. For the analysis of business process

failure, it is also necessary to distinguish two terms:

function and service. In our research, the term func-

tion is used to refer to what the process is intended

to do and is usually detailed in the speciﬁcations in

terms of functionality and performance; and the term

service is used to describe what the instance actually

behaves to achieve the function of the process.

2.2 Framework of Business Process

Failure Analysis

Business Process Failure Analysis (BPFA) has a sim-

ple process, which is shown in Figure 1. During the

analysis process, the business process being reviewed

is ﬁrstly step. The entire business process is modelled

into smaller activities (t1 in Figure 1). Next, the pro-

cess managers can register all possible failure modes

to the system so that the process designers/engineers

can model the propagation behaviour of each activity

according to the failure modes. Then for each activity,

the faults, and possible causes of each faults are iden-

tiﬁed and documented (t3.1 in Figure 1). After all ac-

tivities are analysed, the business process is reviewed

by applying selected faults in the process model and

simulating their propagation process through the busi-

ness process (t4 in Figure 1).

In the process of BPFA, the activity t1 is impor-

tant, but we will not explain it in details because it

has been discussed as the same as in papers of mod-

elling business process in workﬂow net. In this paper,

our focus is the rest activities of BPFA which are real

contributions of our research.

2.2.1 Modelling Failure as Coloured Tokens

Once all activities are identiﬁed, for each activity, the

following steps are performed:

1. Deﬁne the activity being analysed.

2. Deﬁne the functions of the activity being anal-

ysed.

3. Identify all potential failures for the activity.

4. Determine the possible causes of each potential

failure.

During the execution of a business process, a cor-

rect service is delivered when the service satisﬁes the

speciﬁcation of the process function. A service fail-

ure, often abbreviated here to failure, is an event that

occurs when the delivered service deviates from cor-

rect service.

We can describe the failure of a process from the

following dimensions/categories:

• completeness, whether the outcome of the pro-

cess is complete?

• validity, whether the outcome of the process last

for a right period of time?

• consistency, whether the outcome of the process

is consistent whenever the process is executed?

• timeliness, whether the outcome of the process is

generated on time?

• accuracy, whether the outcome of the process is

adequate for the purpose?

To identify the possible failures of an activities

and then analyse them in a systematic approach, we

designed a set of tables to help the analysis and the

documentation. Table 1 is an example. The table is

activity-based, i.e, there is a table for each activity.

For each activity we need to list all possible failures

in each failure dimensions/category listed above, and

the references which cross-links the failure to the re-

quirements or standards of the activity. In the table we

also have to identify the possible causes of each fail-

ures which can help us to trace back the root of each

failure. Table 1 lists a part of this failure analysis of an

activity (Blood Test) in the process of stroke care in

hospital ER department. For the category complete-

ness, the activity may have a failure of incomplete-

ness, i.e, less results of blood test provided. This fail-

ure is directly against the requirements of the national

clinic guide.

In the analysis, we cared about not only all pos-

sible failures at each activity, but also the causes of

MODEL-BASED FAILURE ANALYSIS OF BUSINESS PROCESS

389

Figure 1: BPFA process.

those failures. The operation of an activity in the busi-

ness process is designed to transform inputs into use-

ful outputs. However, the failure may occur during

the operation of the activity. The causes can be either

the incorrect result of previous activity in the process,

or some internal errors during the operation of this ac-

tivity. By modelling the business process with failures

as a coloured workﬂow net, we can easily deﬁne each

activity may have one of following failure behaviours:

• propagation, the colour of output token is as same

as input token’s of an activity;

• transformation, the colour of output token is dif-

ferent.

An example of failure behaviours can also be

found in Table 1. In its operation of this activity, new

failure can be introduced due to internal errors; or fail-

ure transformed from one to another (e.g., informa-

tion that is erroneous when it received at the activity

remains erroneous when it delivers to the next activ-

ity), or transforms to a failure of a different category

(in Table 1, an incorrectness failure is transformed to

an incompleteness failure by the activity Blood Test.).

Once the failure analysis of all activities has been

done, the rest work is to simulate the process model

and review the results of the simulation.

2.3 Failure Analysis of the Business

Process

In general, failure net is based on the workﬂow net

model of a business process with an extension of

coloured tokens. Coloured tokens models fault ser-

vices of activity, and the correct service of an activity

is mark with default colour(i.e, black).

Simply speaking, the purpose of failure analysis

of a business model is to answer the questions listed

at the beginning of this paper. Simulation of Petri nets

as mature technique and well-supported by most tool

can ﬁt for this purpose. By review the results of the

simulation, the failure behaviours of a business pro-

cess can be explored in much details so that the eval-

uation or re-engineering work of the business process

can be done.

2.4 Tool Support

WoPeD (Workﬂow Petri Net Designer)

is an open-

source software. It provides a simple software tool for

modelling, simulating and analysing workﬂow pro-

cess and resource descriptions using workﬂow nets,

an extended class of Petri nets. Based on the codes of

WoPeD, we developed a tool to support our proposed

failure analysis of business process.

3 APPLICATIONS OF FAILURE

NET

In the project, we collaborated with our partners to

help the improvement of NHS stoke care service in

North Yorkshire. In this section, we will brieﬂy

demonstrate how we applied our BPFA to evaluate the

process of stroke care service, and discuss our ﬁnd-

ings of failure analysis of business process in general.

3.1 Failure Analysis of Stroke Care

Process

In the case study, there are 16 key activities in the

process

. For this particular failure (incorrect judge-

ment after activities of review investigation results,

we identiﬁed various reasons which may cause the

failure. And the most important is that we also iden-

tify the most vulnerable activities which may cause

the failure. They are A5 - judgement of application of

urgent thrombolysis with 3 hours, A9 - clinic presen-

tation, A10/11 - review history of health care and

http://www.woped.org/

it excludes the last activity - classify whether is acute

stroke or TIA, or haemorrhagic strok, or other attacks, be-

cause the analysis is performed to identify the key reasons

of causing the incorrect judgement of acute stoke or TIA

patients.

ICEIS 2011 - 13th International Conference on Enterprise Information Systems

390

Table 1: An example of activity failures.

ID: A16 Activity/Process: Blood tests

Index Category Possible Failure Reference Possible Cause

1 Completeness

Incomplete results: Activity

A16 should provide results of at

least 5 different types of blood

test, including blood glucose

level, full blood count (FBC),

urea, electrolytes and creatinine.

Ref 25: The diagnosis and

acute management of

stroke and transient

ischaemic attacks. NICE

2008

Some tests are not

requested by mis-

take.

A15.7: incorrect

judgement of Ac-

tivity A15: Inves-

tigations

Figure 2: An Example of Business Process Failure Analysis.

examinations, and A17 - brain imaging.

During the analysis, we found that the quality of

the services provided by those activities are highly

relied on the experience and skills of the operators.

Thus to improve the quality of entire stroke care ser-

vice in the area, the central/local government should

focus on those key activities and the efforts to improve

the service may include various training, the mecha-

nism of reviewing, etc.

4 CONCLUSIONS

We have presented a new approach for the failure

analysis of business process, based on its failure net

models. The proposed technique enables the assess-

ment of failure behaviour from the analysis of each

activity in the business process. The proposed tech-

nique fully takes the advantages of using Petri net to

model and analyse business processes, but also inte-

grates the techniques of failure analysis from system

engineering with existing techniques in business pro-

cess management. The approach is easy to use and

tool supported.

There are still a lot of work to do in the area of

evaluation of proposed technique and the develop-

ment of tool, for example, we considered to imple-

ment several plug-ins so that business process mod-

elled by other methods, such as UML and BPMN,

can be imported and analysed. We are also explor-

ing techniques to visually represent and automatically

generate analysis results.

REFERENCES

(OMG, 2008). Business process deﬁnition metamodel

(BPDM), Process Deﬁnitions.

MODEL-BASED FAILURE ANALYSIS OF BUSINESS PROCESS

391