SEARCH TREE GENERATION FOR BUSINESS PROCESS
REPOSITORY MANAGEMENT IN THE EXCEPTION
HANDLING OF THE e-COMMERCE DELIVERY PROCESS
Jin Gyu Shin and Doug Won Choi
Systems Management Engineering, Sungkyunkwan University
300 Cheoncheon-dong, Jangan-gu, Suwon, Gyeonggi-do 440-746, Korea
Keywords: Exception handling, Process repository management, Systematic context description, Situation variable,
Decision variable, Search tree generation.
Abstract: BPMS (business process management system) offers the facility to define new processes or update the
existing processes. However, exceptional or non-routine tasks require the intervention of domain experts or
generation of the situation specific resolution process. This paper assumes that sufficient amount of business
process exception handling cases are stored in the process repository. Since the retrieval of the best
exception handling process requires good understanding about the exceptional situation, context awareness
is an important issue. To facilitate the representation of the exceptional situation and to enable the selection
of the best exception handling process, we adopted the 'situation variable' and 'decision variable' construct.
A case example for exception handling in the e-commerce delivery process is provided to illustrate how the
proposed construct works. We applied the C5.0 algorithm to build the optimum search tree.
1 INTRODUCTION
Manufacturing processes usually do not involve so
many exceptional situations. And this property
explains part of the reason why we can automate the
control and management of manufacturing
processes. However, the recent progresses in
software technology enable us to extend the process
automation technology into the area of service and
business processes. Currently there are many
software packages available for the management of
various business processes. Business process
management system (BPMS) is a typical example
(http://www.wfmc.org). Many organizations have
implemented this system and are reported to be
reaping good results (Park, 2004).
It is a difficult job to automate non-routine or
exceptional processes. In order to make a BPMS
handle this kind of non-routine or exceptional
process, we must have a process predefined and
implemented into the BPMS such that it can be
retrieved and applied to the resolution of the
exceptional situation at the time of need (Weske et
al., 2004). An exceptional situation implies a task
which occurs infrequently and has a poorly defined
or undefined rules and procedures. Therefore, it
usually requires the subjective judgement of the
decision maker to resolve the problem.
Exceptional situation falls into the category of
semi-structured or unstructured problems as
discussed in Simon (1960) and Hermann et. al.
(2000). We can improve the task efficiency if we
store the exception handling knowledge into the
knowledge base and have an articulated
infrastructure for sharing the knowledge. Selecting
the right model for the problem situation is an
important issue in decision support system research
(Banerjee and Basu, 1993). In the same vein,
selecting the appropriate process that can best handle
the exceptional situation is an important issue in
BPMS research.
In this paper we introduce the two variable sets,
i.e., situation variable set S= (s
1
, s
2
, … , s
m
) and
decision variable set D= (d
1
, d
2
, … , d
n
), to enable
the systematic context description of the exceptional
problem situation and to render a useful data
structure for optimum search tree generation. The
situation variable set describes the customer
requirements, traffic condition, etc. and is used to
depict the given or uncontrollable aspects of the
problem context. Decision variable set portrays the
121
Gyu Shin J. and Won Choi D. (2009).
SEARCH TREE GENERATION FOR BUSINESS PROCESS REPOSITORY MANAGEMENT IN THE EXCEPTION HANDLING OF THE e-COMMERCE
DELIVERY PROCESS.
In Proceedings of the International Conference on e-Business, pages 121-128
DOI: 10.5220/0002237401210128
Copyright
c
SciTePress
selection of alternative course of action which the
problem solver can adopt to resolve the exception.
The situation variable may circumscribe the scope of
the decision space and the decision maker has to
choose a series of action from the alternative
decision space. Therefore, the specific value
assigned to each decision variable explains which
course of action the decision maker has chosen to
resolve the exception problem. In this paper, the data
structure which is composed of the situation variable
and decision variable plays the key role in designing
the process repository architecture for exception
handling.
Section 2 discusses the related literature review
about exception problems and the corresponding
resolution approaches (Christopher and Lee, 2002;
Eder and Liebhart, 1995; Kappel, et al., 1995; Lee
and Park, 2001; Adams, et al., 2005; Mourão and
Antunes, 2003; Keen and Mcdonald, 2000; Gaonkar
and Viswanadham, 2003) Basic idea about inductive
approach to the selection of exception handling
process is provided in the same section. In section 3
we demonstrate a profile of exceptional situations
that could be encountered in the e-commerce
delivery process. In section 4 we provide the
architecture for exception handling process
repository and present a case study of generating the
process repository which can also be used as the
search tree for selection of the exception handling
process. Section 5 discusses the conclusion and the
issues about future research.
2 THE THEORETICAL
BACKGROUNDS
Eder and Liebhart (1995) classified the failures and
exceptions of business process management system
into four types (Table 1). Based on their work,
Mourão and Antunes (2003) provided the
exceptional situations which can take place at
various stages of the business process and presented
the corresponding solution framework (Table 2).
As is shown in tables 1 and 2, exception handling in
BPMS can be divided into two types: handling of
expected exceptions and unexpected exceptions.
When the exception is unexpected, it may be
resolved by inserting or deleting specific task unit(s)
into the process model at the execution stage. In this
case the workers are allowed to change the work
flow schema dynamically (Eder and Liebhart, 1995)
or some sort of exception handling tools are
provisioned such that the workers may handle the
exceptions for themselves (Kappel, et al., 1995).
Table 1: Type of failure and exception.
Type Stage Instances
Unexpected
exception
Process
execution
stage
•The predefined process
model is unable to
handle the exception.
Ex) Change the
priority of a VIP
customer upon his
re
q
uest
Expected
exception
Process
definition
stage
•Part of the process
cannot be applied. Ex)
Customer failed to pay
the fee/ Failed to
reserve an airline
ticket because it was
alread
y
booked.
Application
failu
r
e
Application
sta
g
e
•Program failure/
Const
r
aint violation
Basic failure System stage
•System break down,
deadlock, network
connection failure,
p
rinter break down
Table 2: Exceptions at various process stages an
d
matching solutions.
Process
sta
g
e
Exceptions Solution Remarks
Strategic
•Unexpecte
exceptions
- employee, team,
or
g
anization
Human
intervention
Tactical
•Expecte
d
exceptions
- Workflow, data,
temporary or
exogenous
p
roble
m
Model the
workflow
adaptive to
the situation
Seek solution
by shifting it
to the
strategic
stage
Operational
• Basic failure,
Application
failure
Traditional
TPS
Shift the
problem to
tactical sta
g
e
The main stream approach to handling the
expected exceptions is to store the matching solution
(sub-process) in the process repository. It is also
possible to include the expected exception handling
process as a sub-process of the normal process
diagram. However, in this case, it is likely to
increase the complexity and reduce the legibility of
the process diagram (Müller, et al., 2004).
Adams et. al. (2005) proposed a binary search
tree in retrieving the exception handling process.
Klein and Dellarocas (2000) provided a hierarchical
structure for storage of various exception handling
processes. In this paper we introduce the data
structure which is composed of the situation variable
S and the decision variable D in order to enable the
systematic description of the exceptional problem
context, and to facilitate the understanding,
classification, and retrieval of the exceptional
situation and the matching exception handling
process. We deploy an e-commerce delivery process
ICE-B 2009 - International Conference on E-business
122
as the case example to demonstrate the usability of
the data structure and how it can be used in
generating the search tree structure which can be
applied to the efficient management of the exception
handling process repository.
Klein and Dellarocas (2000) and Adams et. al.
(2005) reported that most of the preceding process
retrieval system architecture design was based on the
subjective opinion of the domain expert. In this
paper we propose to use the inductive approach in
designing the process retrieval system architecture.
More specifically, we propose to use the induction-
based decision tree structure which can be generated
by applying the ID3-based algorithm C5.0. The
advantage of using the induction-based decision tree
structure is that it provides the logical reasoning
regarding the quest why the induced decision tree is
the best structure for the storage and retrieval of the
exception handling processes.
The advantages of using the decision-tree
structure over other existing process retrieval system
structure in exception handling are summarized as
follows.
1) The decision tree is organized so as to
maximize the information gain. Therefore, it
guarantees the optimal behavior in the storage and
retrieval of the exception handling processes (Han,
2004).
2) The decision tree can be updated anytime as
there are more exception handling processes added
to the process repository. While in Klein and
Dellarocas (2000), they have to convene and hold a
domain expert panel meeting in order to update the
classification hierarchy structure. The worse part of
their scheme is that there is no guarantee of
optimality even after the structure was updated.
3) The context description of the exceptional
situation in terms of the situation variable(S) and
decision variable (D) reflects the implicit knowledge
structure of the domain experts when they make the
decision contingent upon the exceptional situation.
4) The process storage and retrieval scheme
based on the situation variable(S) and decision
variable (D) enables the efficient identification and
recognition of the exceptional situation. It also
enables the efficient retrieval of the exception
handling process that could best resolve the
problem.
Table 3 is the comparison of the process search
methods used by Adams et al.(2005), Klein and
Dellarocas(2000), and this paper .
Table 3: Comparison of the handling methods for expected
exceptions.
Methods
Process repository
structure
Structure
g
eneration
Adams et. al.
(2005)
Binary tree
Expert panel
(subjective)
Klein and
Dellarocas
(
2000
)
Hierarchy tree
This paper
S & D variable
structure for context
description and
decision tree
structure
Expert panel,
Tree induction
(subjective and
objective)
3 SAMPLE EXCEPTIONS IN
e-COMMERCE DELIVERY
PROCESS
The following are samples of extraordinary
exceptions that might happen in the process of e-
commerce delivery. The data are excerpted from the
case book of the e-trade dispute arbitration published
by the Korean Institute for Electronic Commerce
(http://www.kiec.or.kr).
- The item was delivered to a third party (not an
agent) and then got lost.
- An item that exceeds the standard size was
accepted for delivery since there was some extra
space in the delivery vehicle and the competitor was
also accepting such non-standard items under similar
conditions. In this case the operator must identify the
availability of extra space or extra vehicle and has to
follow the complicated procedure to justify the
exception handling.
- A buyer ordered an item from an internet
shopping mall and completed the payment process.
He received a mail from the seller confirming the
order information and notifying that the item was
shipped out. However, the item was returned to the
seller because of the incorrect address. In addition,
the buyer was charged for the return shipping.
- An expensive item was deposited for repair at a
service center. When the item was shipped back to
the owner, he found it damaged due to the faulty
packaging. So he asked for exchange or
compensation. However, the service center refused
the claim because the item was already a second
handed one and they had no regulation for such a
case.
- The seller delayed shipping many times and
eventually cancelled the contract because they were
SEARCH TREE GENERATION FOR BUSINESS PROCESS REPOSITORY MANAGEMENT IN THE EXCEPTION
HANDLING OF THE e-COMMERCE DELIVERY PROCESS
123
unable to procure the inventory. The buyer
experienced a big loss due to this contract failure
and filed a claim for compensation. A complicated
dispute arbitration process is anticipated to resolve
this case.
- A perishable item was ordered. However, the
package was broken in the delivery process and
some other items located adjacent to the package got
tainted. The seller asserted that he had made a tight
packaging. In this case, the dispute arbitration
process must clarify where the responsibility lies.
Decisions regarding return, refund, and
compensation have to be delineated.
Handling these sort of extraordinary exceptions
requires the involvement of the problem domain
specialists or needs to go through a series of problem
specific decision making processes. The hard part of
the task is that it is not easy to automate the entire
task and is mostly processed manually. In this paper
we attempt to find an effective methodology for the
storage and retrieval of the exception handling
processes assuming that a sufficient amount of
exception handling process data are accumulated
over a long period of time.
4 SEARCH TREE GENERATION
In this section we present the process repository
architecture for exception handling and also provide
a case example for generating the decision tree for
storage and retrieval of the exception handling
processes. We use the sample exception data
excerpted from the KIEC case book (see section 3)
in the generation of the decision tree.
4.1 Architecture for Process
Repository
In order to handle the exceptions the process must
go through three stages, i.e., identify the exception,
retrieve the matching exception handling process,
and then resolve the exception (Vojevodin, 2005).
An exception can be identified by monitoring the
current status of an ongoing process. At this stage
every instance of the ongoing process is checked
against exceptionality. And when an exception is
perceived, the type of exception is identified.
Retrieval of the matching exception handling
process is done by looking up the process repository
and finding the best fit process for the exception. At
this stage the situation variable S and decision
variable D play the key role. If a good exception
handling process could be found, then we simply
need to apply it for the exception resolution. If an
appropriate one could not be found, the exception
must be resolved by using one of the approaches
shown in Tables 2 and 3. When it is resolved, the
new exception handling process should be added to
the process repository. Figure 1 shows the
architecture of the exception handling process
repository system.
Figure 1: Architecture for exception handling process
repository.
4.2 Variable Definition and Data
Preparation
The following example explains the process of
generating the search tree which can be utilized for
selecting the matching process for handling the
identified exception. In this paper, the C5.0
algorithm of SPSS Clementine package was used to
obtain the induction based decision tree (Han, 2004).
The overall steps of generating the search tree are as
follows.
- Define the situation variable S and decision
variable D
- Collect the case examples of exception handling
process
- Prepare the input data according to the C5.0 input
format
- Generate the search tree using C5.0
Table 4 is the sample definition of the situation
variables and decision variables that can be used to
describe the various exceptions that may occur in the
e-commerce delivery process. Christopher and Lee’s
(2002) previous work was referenced in the variable
definition. They grouped the delivery exceptions
into two categories: ‘customer originated’ and
‘system originated’ exceptions. Some modifications
ICE-B 2009 - International Conference on E-business
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Table 4: Situation variable and decision variable.
Origin of
exception
Situation variable Decision variable
Customer
• Order change
- Type of order
change
- Delivery status
• Cancel order
•Order change
processing
- item(name, price,
shipping charge)
- destination
(location, recipient)
- delivery date
(delayed, expedited)
- Shipper
- Delivery channel
(door to door, seller
delivery, special
delivery)
- Return charge payer
(customer, seller)
- Urgency
(emergency, normal)
•Cancellation
(
allowed/disallowed
)
System
factor
(failure
/break
down)
•Delayed delivery
- Traffic
- condition turned
worse
•Traffic accident
- type of accident
• Problem in
production stage
- abnormal
production
- abnormal quality
•Carrier problem
- car break down
•Problem with the
shipped item
- damage in item
•IT system problem
-central control
system disorder
-transportation
system disorder
-wireless
communication
disorder
(cell phone, PDA)
•Routing problem
- Natural disaster
(earthquake,
typhoon)
•Shipping cost
increased
- environment change
(oil price up,
consumer price up)
•Production stopped
(
fire,
p
ower failure
)
•Traffic ja
m
- availability of nearby
alternative carrier
•Degree of car damage
•Alternative supplier
-agreement with the
original supplier
•Car damage level
- Car operational
- Availability of nearby
carrier
•Compensation level
•Alternative means of
communication
- Back up server system
- Public phone
• Alternate delivery
- adjust schedule
- business partner
• change shipping
charge
• Alternate supplier
have been made to fit the sample example situation.
Table 5 and Table 6 are the modified version of the
situation variable and decision variable with
reference to the variable definition of Table 4.
Most BPM systems have the facility to monitor
the system behavior and store the log data of
theiness activities. When substantial amount of log
data are collected, the BPMS renders the analysis of
the workflow status and analysis of the system
performance record. In this regard the log data is a
good source of case examples which contain lots of
information about situation variable and decision
variable. This observation justifies the fact that
constructing a process repository system from
system log data is a viable approach.
Figure 2 shows part of the 145 data set used in ge
nerating the process search tree. Since this is an adva
nced research, no real field data is available as of thi
s paper writing.
Table 5: Situation variable – example.
Variable(s
i
) Value
Order change
type
item, shipping destination, delivery
time, delivery medium
Delivery status
b
efo
r
e shipping, In delivery,
Delivered, In return(w/RMA), In
exchan
g
e deliver
y
Delivery type
normal, bundle, return, exchange,
re-exchange, exchanged and
cancelled
Priority
(schedule)
normal, expedited, special,
designated date, delayed
Destination
incomplete address, address
changed, moved during delivery
Payment
prepaid, deposit payment & balance
payment, deferred pay, escrow
Recipient
buyer, agent, third party, agent of
absence, P.O. box
Item description
item name, price, shipping charge,
quantity
Condition
new, used, damaged, defective,
broken in use, special
handling(fragile, perishable,
indemnity of damage in delivery,
frozen)
Standard volume, weight, special care
Received yes, no
Empty vehicle available number, load factor
Delivery type
door to door, seller delivery,
registered mail, regular mail
Type of trade
e-shopping mall, specialty e-store,
open market, auction, direct trade
SEARCH TREE GENERATION FOR BUSINESS PROCESS REPOSITORY MANAGEMENT IN THE EXCEPTION
HANDLING OF THE e-COMMERCE DELIVERY PROCESS
125
Figure 2: Sample usage of the situation variable and decision variable used in generating.
Table 6: Decision variable – example.
Variable (d
j
) Value
Delivery charge
Seller pay, buyer pay, special
contrac
t
Return shipping charge
Seller pay, buyer pay, logistics
co., undecide
d
deliverer
Current deliverer, new deliverer,
substitute
Item o
p
ened & use
d
y
es, no
Cause of return
Simple change of min
d
, wrong
item, delayed delivery, not
specified, item damaged, wrong
p
rice
Returned item
condition
Item damage
d
, goo
d
,
p
ackage
dama
g
e
d
Sti
p
ulated in the
a
g
reemen
t
clear, unclear
Sufficient info
p
rovide
d
yes, no
buyer’s fault verified, not verified
Buyer verified
defective
verified, not verified
Exception
handling
process
Change the order item,
Adjust delivery
priority(schedule),
Change destination,
Cancel order,
Change delivery carrier,
Cancel order and refund,
Partial refund,
Return and exchange ship,
Compensation for buyer,
Compensation for seller, Hold
the contrac
t
The sample data shown in Figure 2 are
compilation of the sample data in the KIEC case
book of e-trade dispute arbitration
(http://www.kiec.or.kr).
As the summary of the variable definition, we
had 8 situation variables, 9 decision variables, and
one out variable which is equivalent to the matching
exception handling process.
4.3 The Search Tree Generation
The search tree we obtained from C5.0 algorithm
with the data set shown in Figure 2 is provided in
Figure 3. The leaf nodes in Figure 3 indicate the
processes which best fit the given exceptional
situation. The tree diagram in Figure 3 indicates that
the situation variables used in the storage and
retrieval of the exception handling processes are
‘delivery status’ ‘returned item condition’ and ‘type
of trade.’ And the decision variables are ‘return
shipping charge payer’ ‘cause of return’ ‘item type’
and ‘stipulated in the agreement.’ The diagram also
tells us that the most influential (effective) variable
is ‘delivery status.’ (located at the root)
ICE-B 2009 - International Conference on E-business
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Figure 3: Decision tree for storage and retrieval of the exception handling processes in e-commerce delivery.
SEARCH TREE GENERATION FOR BUSINESS PROCESS REPOSITORY MANAGEMENT IN THE EXCEPTION
HANDLING OF THE e-COMMERCE DELIVERY PROCESS
127
5 CONCLUSIONS
In the earlier research, the process repository archi-
tecture design for exception handling was mostly
done by the subjective judgement of the domain
experts. This paper presented an alternative
approach which utilized the C5.0 algorithm to obtain
the decision tree structure that provided the optimal
path to store and retrieve the exception handling
processes. The use of ‘situation variable’ and
‘decision variable’ structure for the context
description of the exceptional problem is an efficient
way to identify the problem context and to find the
best fit exception handling process. Since the search
tree is constructed based on the ID-3 algorithm, each
step of the tree traversal from the root down to the
leaf node proceeded in such a fashion to maximize
the information gain.
As more and more exception handling processes
are added to the repository, we need to update the
search tree. As long as we keep describing the
exceptions in terms of the situation variable and
decision variable, updating the search tree for
renewal of the optimality will be a handy task since
we simply have to run the C5.0 algorithm with the
updated data set. Since we can anticipate a
substantial change in the search tree organization
every time we update the search tree, we have to
provide the facility to accommodate the tree
structure change into the database implementation.
And this should be the topic for future research.
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