International Journal of Scientific and Research Publications, Volume 3, Issue 10, October 2013
ISSN 2250-3153
1
A CASE STUDY OF RISKS OPTIMIZATION USING
AHP METHOD
Shivani Sharma1 and Ravindra Pratap2
Master Student, Mechanical Engineering Department, HCTM Technical Campus, Kaithal – 136027, Haryana, India
1
Email:
[email protected]
Associate Professor & Head, Mechanical Engineering Department, HCTM Technical Campus, Kaithal – 136027, Haryana, India
2*
Email:
[email protected]
Abstract- Worldwide Competitiveness today, means that the
3) An Analytical Hierarchy Processing (AHP) method with
customer is Utmost. As the customer is supreme, only those
enhanced Consistency to rank risk factor for suppliers is created
enterprises are going to be prosperous which are able to provide
for getting risks optimization requirement.
goods and services to the customer in timely, cost effective
manner and also provide quality, which not only satisfies him but
also delights him. Considerable research has been carried out and
Index Terms- Supply Chain, Analytical Hierarchy Process
(AHP), Risk, Supply Chain Management, Optimization
literature available in the field of Supply Chain Management
I. INTRODUCTION
since 1990. Successful supply chains use integrated measurement
systems as a tool to achieve their organizational objectives. A
Risk
management
is
a
critical component
of
strategy
comparative analysis of various risks factors reduces the chance
development and execution, and a driver of firm success. A
of its occurrence. It indicates that validity of many of the
survey of researchers found that 74.2% of respondents believe
measurement frameworks need to be established through further
supply chain risk management (SCRM) is a subset or extension
study. The process of choosing appropriate supply chain
of ERM (Sodhi et al., 2012). While there has been an increasing
performance measures is difficult as a result of the complexity of
amount of SCRM research, there is no consensus on the
these systems. The main motive of this paper is risk
definition or scope of SCRM (Sodhi et al., 2012). For example, a
identification and determining risk optimization, which are more
three-step SCRM process has been proposed: (1) specifying
severe for the Company.
sources of risks and vulnerabilities, (2) assessment, and (3)
mitigation (Kleindorfer and Saad, 2005). Other researchers
The vital motive of this analysis to review the literature in the
proposed a four-step processes (Hallikas et al., 2004; Juttner et
field of various risk factors for supply chains to understand
al., 2003), while others propose a five-step process (Manuj and
current practices and to help Industry to sustain its continue win
Mentzer, 2008). Though common elements appear across all
in flat market where the competition is cut throat these days.
these frameworks, there is not yet agreement on what
To accomplish this objective following steps have been
components and definitions constitute a “standard” SCRM
performed:
process. Even without agreement on broad SCRM frameworks, a
variety of supply risks and risk management strategies have been
1) Literature review on supply risk as well as a series of industry
identified. Supply risks have been classified as supplier, market
interviews
and item risks (Zsidisin, 2003) for example. Specific risks
2) From Risks factors, a Hierarchical Risk Factor classification
structure is created
include order fulfillment errors, information distortion,labor
disputes,
natural
disasters,
capacity
shortages,
supplier
bankruptcy, exchange rate risks,government regulations, single
sourcing, and port delays for example (Blackhurst et al., 2005;
www.ijsrp.org
International Journal of Scientific and Research Publications, Volume 3, Issue 10, October 2013
ISSN 2250-3153
2
Manuj and Mentzer, 2008; Tummala and Schoenherr, 2011;
are evaluated and defined. The criteria weights can be more
Zsidisin and Hartley, 2012). Different risks require different
precisely defined by the AHP methodology using “Saaty scale”
SCRM processes (Zsidisin and Wagner, 2010). Supply chain risk
than using the digital logic method. However, subjectivity is
management strategies include environmental scanning (Zsidisin
playing a great role in both of methods. Subjectivity is included
et al., 2004), use of capable suppliers (Manuj and Mentzer,
to the comparison of alternatives by the original AHP
2008), dual sourcing (Khan and Burnes, 2007), contingency
methodology, also. Contrary, by using other method there is no
planning (Kleindorfer and Saad, 2005), supplier credit analysis
subjectivity concerned of alternatives comparisons because of
(Kern et al.), inventory buffers (Tang, 2006),integration of
dealing with transformed values of criteria. The ranking of all
information systems and supply chain modeling (Giannakis and
alternatives can be performed, by obtaining the priorities. Criteria
Louis, 2001), and speculation, hedging and forward buying
(sometimes called objectives or attributes) are the quantitative or
(Zsidisin and Hartley, 2012) for example. Firms face multiple
qualitative data (judgments) for evaluating the alternatives. In
supply risks, whether in combination or isolation. Each risk
AHP methodology, the term properties is equivalent to the term
might require a specific SCRM technique (Zsidisin & Wagner,
criteria. The weights of the criteria present the relative
2010). SCRM treatment options include evaluation and trust
importance of each criterion compared to the goal. Finally,
building (Laeequddin, Sardana, Sahay, Abdul Waheed, & Sahay,
alternatives present the group of feasible solutions of the decision
2009), use of dual
problem. Alternatives are evaluated against the set of criteria.
sources (Khan & Burnes, 2007),
environmental scanning (Zsidisin, Ellram, Carter, & Cavinato,
2004), combined capacity reservation contracts and spot markets
Different phases of method are as follow:
(Inderfurth & Kelle, 2011), qualification and use of capable
1. Structuring the problem and building the AHP model.
suppliers
2. Collecting the data from expert interview.
(Manuj
&
Mentzer,
2008),
supplier
quality
management initiatives (Holschbach & Hofmann, 2011), buffer
3. Pairwise comparison of each factor.
inventory (Tang, 2006), contingency plans (Kleindorfer & Saad,
4. Calculation of consistency index to rank Optimization
2005),
credit
analysis
(Kern,
Moser,
Hartman,
&
Moder),strategic sourcing and flexibility (Chiang, Kocabasoglu-
requirement of each risk.
Note: All the Calculations/Tables are below in Appendix
Hillmer, & Suresh, 2012), forward buying or hedging (Zsidisin &
Hartley, 2012) and supplier development (Matook, Lasch, &
Tamaschke, 2009) for example. Despite the plethora of risks and
risk management approaches, few firms have a structured SCRM
approach (Martin, Mena, Khan, & Yurt, 2011).
III.RESULT ANALYSIS
The AHP model in this study is formed to prioritize the
various risks within the organization. Pairwise compa rison
is
done according to the table of scale 1 to 5 (see in table1).
Consistency ratio (CR) is calculated to the degree of consistency
In this paper, presenting a model for assessing risk in supply
chains based on the Analytic Hierarchy Process (AHP). The AHP
supports managers in prioritizing/optimization the supply chain
objectives, identifying risk indicators, put all the risk on severity
scale to identifying risk optimization requirement. It is followed
by the discussion of AHP methodology and prioritization of
factors for coordinated supply chain. Eventually, it discusses
results and conclusion.
II. METHOD AND PROCEDURE
of pair wise compression Risks are ranked according to highest
Principal Vector. If CR is less than 10%, judgments are
considered consistent. And if CR is greater than 10%, the quality
of judgments should be improved to have CR less than or equal
to 10%. In this study, the CR is 0.0141 which is less than 10% .It
implies that decision taken by expert is satisfactory for further
analysis. Thus the firm has consistent risk by the use of AHP
In this Paper, AHP (Analytical Hierarchy Process) methodology
method. Here the most critical risks are industrial risk and then
has been applied to the evaluation of risk related to supply chain
product related risk according to their principal vector value (see
management in a manufacturing firm. Five risks for the company
in table 3) that require optimization at maximum level. The
www.ijsrp.org
International Journal of Scientific and Research Publications, Volume 3, Issue 10, October 2013
ISSN 2250-3153
industrial risk must be dealt with to reduce the losses to the
supply chain management. The sub factors associated with the
3
REFERENCES
1.
Barry, J. (2004), ‘‘supply chain risk in an uncertain global
industrial risk should be solved according to their ranking.
supply chain environment’’, international journal of physical
Therefore it is advised to the company to deal with reducing the
distribution & logistics management, vol. 34 no. 9,
most ranked risks so that the supply chain of the firm can
2.
An AHP Lesson from International Hellenic University.
function without loss.
3.
Boer Labro, E. And Morlacchi, P. (2001), “a review of
methods supporting supplier selection”, European journal of
IV.CONCLUSION
purchasing & supply management, vol. 7 no. 2, pp. 75-89.
The AHP concepts in manufacturing supply chain should be
studied with precision which is the need of the hour, as
manufacturing supply chain is becoming less vertically
integrated and the manufacturer is focusing on its core
competency. Using AHP method the study of various risks is
done here that which risk is more critical here for any industry.
Therefore, a structured, simple and efficient proposed decision
framework is proposed and has the ability to show the direction
to determine the degree of impact level of each RF (Risk Factor).
The degree of impact level of each RF of the firm will give idea
for optimally allocating the efforts to gain maximum benefit. A
case situation is revealed in order to reinforce the salient features
of the proposed framework. The results indicate that the
industrial risk and then product risk have got the highest impact
on successful implementation of SC. Further research is
suggested to develop a decision framework that can able to find
out optimal number of solutions for identifying and mitigating
the most influencing factors of the supply chain in a specific
environment.
4.
Christopher, M. And Lee, H. (2004), “mitigating supply
chain risk through improved confidence”, International
journal of physical distribution & logistics management, vol.
34 no. 5, Pp. 388-96.
5.
Cooke, J. (2002), “brave new world”, logistics management
and distribution report, vol. 41 no. 1,Pp. 31-4.
6.
Chopra and Sodhi, 2004 S. Chopra and M.S. Sodhi,
managing risk to avoid supply-chain breakdown, mit sloan
management review 46 (1) (2004), pp. 53–62.
AUTHORS
Shivani Sharma,
[email protected]
Ravindra Pratap,
[email protected]
Correspondence Author – Shivani
Sharma,
[email protected],
[email protected],+9
1- 8288012436.
Appendix
Phase 1.Structuring the hierarchy model of factors
This phase involve formulating the hierarchy of AHP model consisting of goal ,factors & sub factors, the goal of our problem is risk
management/optimization and various risk factors as planning risk, product risk, environment risk, industrial risk ,productivity risk
and those are father divided into several sub factors.
Phase2. Collecting the data through expert interview:
After building the AHP model the next step is measuring and collecting the data, which involves the group of expert and assigning
pair wise comparison to the various risks, using the table of five point scale (this scale is called the Saaty Scale), a questionnaire set is
prepared that consists of all the factors and sub factors .The expert will assign a score to each risk compare to other risk from the range
of 1 to 5 (Table 1 ).
Table-1 Scale for Rating
Intensity of importance
Definition
Explanation
1
Equal importance
Two factors contribute equally to the objective.
2
Somewhat more important
Experience and judgment slightly favor one over
www.ijsrp.org
International Journal of Scientific and Research Publications, Volume 3, Issue 10, October 2013
ISSN 2250-3153
4
the other.
3
Much more important
Experience and judgment strongly favor one
over the other.
4
Very much more important
Experience and judgment very strongly favor
one
over
the
other.
Its
importance
is
demonstrated in practice.
5
Absolutely more important
The evidence favoring one over the other is of
the highest possible validity.
Reciprocal
While comparing reversely one risk to other,
value would be 1/original comparison.
The risk factors (RF) are identified through literature review and in consultation with expert opinions from managers, senior engineers
and engineers from Indian Manufacturing Industries. In order to prioritize the RFs, RFs should be compared among themselves on the
basis of the questionnaire. Therefore, AHP is used for prioritization of RFs as it has the ability to capture both quantitative and
qualitative decision criteria. Analytic Hierarchy Process (AHP) was developed in 1972 as a practical approach in solving relatively
complex problems. The AHP allows decision maker to model a complex problem as a hierarchical structure that shows the
relationship between the goal, primary criteria, sub-criteria and alternatives. It is used for multi-criteria problems in a number of
application domains. The step by step algorithm used is shown below.
Step 1: The pair-wise comparisons among the RFs are developed on the basis of expert judgments. A scale of 1 to 5 as shown below
Table 2 is used for pair-wise comparisons. The pair-wise comparisons are done in terms of which a RF dominates another. These
judgments are then expressed as integers. If RF A dominates over RF B, then the whole number integer is entered in row A, column B
and reciprocal is entered in row B, column A. If the RFs being compared are equal, a one is assigned to both positions.
Step 2: Construct a set of pair-wise comparison matrices for RFs on the basis of the opinions of all pre decided number of experts.
Step 3: There are several methods for calculating the eigenvector. By making each column of matrix normalized by dividing each
value of column by sum of column, this would normalize the values.
Step 4: The next stage is to calculate λmax (max Eigen Value), multiply on the right the matrix of judgments by the eigenvector,
obtaining a new vector. The product Aω and the AHP theory says that Aω = λmaxω (For such a Aω Square matrix, ω is said to be an
eigenvector (of order n) and λ is an eigenvalue) so we can now get estimates of λmax by the simple expedient of dividing each
component, by the corresponding eigenvector element,check consistency the pair-wise comparison matrix using the Eigen value.
Step5: In Analytic Hierarchy Process (AHP) method Finally, a Consistency Index can be calculated using formula (λmax- n)/(n- 1).
That needs to be assessed against judgments made completely at random and Saaty has calculated large samples of random matrices of
increasing order and the Consistency Indices of those matrices. A true Consistency Ratio is calculated by dividing the Consistency
Index for the set of judgments by the Index for the corresponding random matrix. Saaty suggests that if that ratio exceeds 0.1 the set of
judgments may be too inconsistent to be reliable. In practice, CRs of more than 0.1 sometimes have to be accepted. If CR equals 0
then that means that the judgments are perfectly consistent.
Phase 3. Pairwise comparison of each factor.
www.ijsrp.org
International Journal of Scientific and Research Publications, Volume 3, Issue 10, October 2013
ISSN 2250-3153
5
Table 2 - Pair wise compression matrix
PPR
PR
ENR
INR
DMR
PPR
1.00
1/3
2.00
1/4
1/2
PR
3.00
1.00
4.00
1/2
2.00
ENR
½
1/4
1.00
1/5
1/3
INR
4.00
2.00
5.00
1.00
3.00
DMR
2.00
1/2
3.00
1/3
1.00
10.5
4.08
15
2.28
6.83
SUM OF COLM
Table 3 – Normalized matrix
PPR
PR
ENR
INR
DMR
PPR
0.10
0.08
0.13
0.11
0.07
PR
0.29
0.25
0.27
0.22
0.29
ENR
0.05
0.06
0.07
0.09
0.05
INR
0.38
0.49
0.33
0.44
0.44
DMR
0.19
0.12
0.20
0.14
0.15
Phase 4. Calculation of consistency index to rank Optimization requirement of each risk
Table 4- Average value matrix
Factors
Eigen Vector
Principle
Vector
Optimization Ranking
PPR
0.10
0.23
IV
PR
0.26
0.62
II
ENR
0.06
0.15
V
INR
0.42
1
I
DMR
0.16
0.38
III
Table 5- Average Eigen value
FACTOR
S
New Vector
λ (New Vector/PV)
PPR
0.49
5.02
PR
1.34
5.10
ENR
0.31
5.03
INR
2.13
5.11
DMR
0.81
5.06
www.ijsrp.org
International Journal of Scientific and Research Publications, Volume 3, Issue 10, October 2013
ISSN 2250-3153
6
Consistency Index (CI) = (λ max - N) / N – 1
Consistency Ratio (CR) = CI/RI corresponding to N
λmax = average of the RFs of λ.(see table 5)
Where RI: Random Consistency Index (see Table 6 ) and N: Number of RFs
Table 6-Random consistency index
N
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
RI
0
0
0.58
0.9
1.12
1.24
1.32
1.41
1.45
1.49
1.51
1.48
1.56
1.57
1.59
λMAX
=
5.06
N=5
CI =
λMAX - N
CI =
0.0158
N- 1
CR =
CI
RI
CR =
0.0141
www.ijsrp.org