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ORIGINAL ARTICLE
Selection of manufacturing process using graph theoreticapproach
Mohit Singh • I. A. Khan • Sandeep Grover
Received: 24 October 2011 / Revised: 17 January 2012 / Published online: 5 February 2012
� The Society for Reliability Engineering, Quality and Operations Management (SREQOM), India and The Division of Operation and
Maintenance, Lulea University of Technology, Sweden 2012
Abstract To manufacture a product, nowadays there are
many methods available in the market to manufacture them
and to earn more profits and best production which is the
prime focus of any manufacturing industry, it is necessary to
select only that type of manufacturing process which leads to
more profits, less scraps, and reworks, faster production rate,
good quality of production, employee satisfaction, customer
satisfaction, etc. So the aim of this paper is to judge the best
manufacturing process among various manufacturing pro-
cesses for manufacturing any product using graph theoretic
approach. The graph theoretic approach reveals a single
numerical index and accordingly it is possible to choose the
best manufacturing process. To apply the graph theoretic
approach the authors selected four factors namely: Quality,
Cost, Technical Capability, and Production. Based on these
factors and their co-factors a fish bone diagram is repre-
sented. While applying graph theoretic approach a digraph of
the characteristics is drawn which represented the factors and
co-factors affecting the selection of manufacturing process
and further the interdependency of the factors as well as their
inheritances has been identified and its representation in the
matrix form has been used for the calculation of numerical
index of the manufacturing process through its variable
permanent quality function. The technique is applicable
when there are more than options are available for manu-
facturing a product. An example is also shown in the last of
the paper to understand the application of graph theoretic
approach for the selection of best manufacturing process
among three processes.
Keywords Manufacturing organization � Selection
process � Graph theoretic approach
1 Introduction
The main goal of any organization is to achieve more and
more profits with effective customer satisfaction so that the
organization can play effectively in the market, and to fulfill
this goal it is necessary to select a proper manufacturing
system carefully. A company with an excellent manufac-
turing process produces a quality product which passes
stringent inspections and gains customer recognition. The
benefits of a good, solid manufacturing process are: quality
products, decreased labour cost, high employee morale,
positive image, higher profits, etc. It is therefore important to
develop designing aids which would assist designers in the
selection of materials and manufacturing processes (Perzyk
and Mefta 1998). The manufacturing process should be
flexible and precise enough so that during the fabrication it is
possible to reach the required tolerances. The manufacturing
process should also bear low cost, low scrap, and rapid in
order to be competitive (Jahazi and Hossein-Nejad 2004).
To predict or compare the performance of a manufac-
turing process, it is necessary to analyze various factors and
their effect. Therefore, a mathematical model is required to
correlate the different factors, sub-factors to evaluate and
M. Singh (&) � I. A. Khan
Department of Mechanical Engineering, Jamia Millia Islamia,
New Delhi, India
e-mail: [email protected]
I. A. Khan
e-mail: [email protected]
S. Grover
Department of Mechanical Engineering, YMCAUST, Faridabad,
India
e-mail: [email protected]
123
Int J Syst Assur Eng Manag (Oct-Dec 2011) 2(4):301–311
DOI 10.1007/s13198-012-0083-z
compare the manufacturing processes. The present works
undertakes the application of graph theoretic approach in
the manufacturing process in manufacturing industry.
2 Graph theoretic approach
A graph theoretic model is a versatile tool that has been
used in various applications. It helps to analyze and
understand the system as a whole by identifying system
and subsystem up to the component level. The conven-
tional approach of representation vis-a-vis block diagram,
flow diagram, schematic representation, etc., is suitable for
the visualisation of relationships/interactions but not for
any mathematical analysis. Whereas the mathematical
model developed by graph theoretic approach, considers
both the contribution of factor itself, i.e., the inheritance of
factor and extent of dependence among factors, i.e., their
interactions. This methodology starts from where conven-
tional representations end. This logical and systematic
approach uses well-documented applications of graph
theory (Narsingh 2000; Robinson and Foulds 1980).
Digraph representation is useful for modelling and visual
analysis. Matrix representation is useful in analyzing the
digraph model mathematically and for computer process-
ing. Permanent multinomial function characterizes the
system uniquely and the permanent value of a multinomial
represents the system by a single number, which is useful
for comparison, ranking, and optimum selection.
The value of the manufacturing process index is iden-
tified using the unified structural approach called graph-
theoretic-methodology. The graph theoretic approach is
divided into three terms:
1. Digraph representation
2. Matrix representation
3. Permanent function representation
2.1 Digraph representation
A digraph is used to represent the factors and their inter-
dependencies in terms of nodes and edges. The nodes
represent the measure characteristic, whereas edges repre-
sent interdependence between them. An example of four
characteristics digraph is shown in Fig. 1.
2.2 Matrix representation
The digraph provides a visual representation which is
fruitful up to a limited extent. If the number of character-
istics are increases then the digraph becomes complex, so
to resolve this complexity the matrix representation is
developed. If the digraph contains N nodes, then its matrix
representation is of size N 9 N, in which diagonal ele-
ments represent the dependence among the characteristics.
The matrix is also known as the variable permanent matrix
(VPM) corresponding to four characteristics digraph is
given as
VPM¼
H1 H12 H13 H14
H21 H2 H23 H24
H31 H32 H3 H34
H41 H42 H43 H4
0BB@
1CCA
2.3 Permanent function representation
To determine the numerical index, the permanent of the
matrix, called as variable permanent function is used here.
The permanent function is obtained in a similar manner as
its determinant but with all signs positive. This expression
is representative of the manufacturing process and contains
all possible quality terms of the manufacturing organiza-
tion. The VPF expression corresponds to the four charac-
teristics digraph/VPM is represented by Eq. 1 as follows:
VPF ¼H1H2H3H4
þ h12h21H3H4 þ h13h31H2H4 þ h14h41H2H3
þ h23h32H1H4 þ h24h42 H1H3 þ h34h43 H1H2
þ h12h23h31H4 þ h13h32h21H4 þ h12h24h41H3
þ h14h42h21H3 þ h13h34h41H2 þ h14h43h31H2
þ h23h34h42H1 þ h24h43h32H1
þ h12h21h34h43 þ h13h31h24h42 þ h14h41h23h32
þ h12h23h34h41 þ h14h43h32h21 þ h13h34h42h21
þ h12h24h43h31 þ h14h42h23h31 þ h13h32h24h41
ð1Þ
3 Identification of attributes
To select the best manufacturing process using graph the-
oretic approach, it is necessary to identify the attributes
affecting the manufacturing process significantly. As per
the literature review, the attributes and their co-factors
Fig. 1 Four-characteristic quality digraph
302 Int J Syst Assur Eng Manag (Oct-Dec 2011) 2(4):301–311
123
affecting the selection of manufacturing process are as
following:
1. Quality: low defect rate, commitment to quality,
improved process capability
2. Cost: processing cost, maintenance cost, product cost
3. Technical Capability: flexibility, efficiency, mechanism
4. Production: production rate, packaging, delivery
Factors affecting the selection of manufacturing process
are represented by a fishbone diagram as shown in Fig. 2.
The fishbone diagram identifies the main factors as Cost,
Quality, Technical Capability and Production. Each branch
or bone shows main factors whereas the sub branches
connected to main branches shows the co-factors of main
factors. The diagram represents that how these factors and
co-factors affect the manufacturing process.
3.1 Quality
The term Quality in reference to manufacturing process
meant for such processes and methodologies that ensure
that the manufactured products meet the required quality
standards consistently. The process should produce goods
right at the first time, without any rework. In an imperfect
manufacturing process, a certain proportion of products
become defective due to poor production quality and
material defects, and subsequently defective products are
scrapped if they are not re-workable or it is not cost-
effective to do so (Sarker et al. 2008). The term Quality is
very crucial for the manufacturing processes. With so much
competition and such few margins, no manufacturing
industry can afford to spend time and money on rework.
Every activity in the industry costs money and so does
rework, but customers do not pay for rework. Customers
pay for the value addition by the company and if they see
more valuable additions by some other company being
offered at same or lower costs, they move to that company.
Hence to assure good quality to customers, quality pro-
cesses plays a significant role.
3.2 Cost
The manufacturing process should be cost effective, as the
competition is increasing at a very faster rate. The current
trend forces companies to produce low-cost and high-
quality products in order to maintain their competitiveness
at the highest possible level (Shehab and Abdalla 2001).
Figure 3 postulates that cost can be regarded as a function
of technical factors, such as cycle time, downtime, reject
rate, equipment and tooling requirements, or the material
used (Field et al. 2007). These technical factors, including
operational inefficiencies, drive the quantity of factor
resources that are required to produce a given level of
output for a given type of technology. Understanding the
effect of these underlying technical cost drivers can pro-
vide insight for managers and engineers as to what process
improvements are most critical to lower production costs
(Fuchs et al. 2006). It has been proposed that reducing the
number of parts in a product will result in cost savings
(Ernst 1987). IBM increased productivity by 700% after
Manufacturing process
Cost
Technical Capability
Production
Maintenance Cost
Product Cost
Flexibility
Efficiency
Mechanism
Production
Packaging
Delivery
Quality
Commitment to quality
Improved process capability
Low defect rateProcessing Cost
Fig. 2 Fish bone diagram of
manufacturing process
Fig. 3 Process-based cost
modeling framework (Field
et al. 2007)
Int J Syst Assur Eng Manag (Oct-Dec 2011) 2(4):301–311 303
123
reducing part count by two-thirds; Ford reduced the part
count in its door trim by 79%, assembly cost by 94%, and
material cost by 27% (Johnson and Kirchain 2009). Also
similar models have been developed to examine the pro-
duction of many technologies including both structural
(Fuchs et al. 2008; Ruffo et al. 2006) and electronic
components (Fuchs et al. 2006; Singer 2004).
3.3 Technical Capability
The term Technical Capability is an important factor which
influencing the selection of manufacturing process signifi-
cantly. Understanding the structure of a process and
quantifying process performance no doubt are essential for
successful quality improvement initiatives (Chien-Wei
et al. 2009). Growth accounting studies typically find a
very large proportion of growth is due to the ‘Solow
residual’ which includes technological progress (Best
2001). So, an important part of more rapid growth is the
ability of firms and their workers to learn how to upgrade
their production capabilities and access new markets (Te-
wari 2002).
3.4 Production
All manufacturing process has some strengths and weak-
nesses. But the prime motive is to determine an actual
balance between the desired production and cost because it
is obvious that, faster production and greater precision
generally increased the cost of product which is always
undesirable. So to find the best manufacturing process, it is
necessary to exercise for an accurate and precise manu-
facturing process which can provide desired production
without increasing the cost of product. The manufacturing
process should be of such type which can provide higher
production rate at low cost, easier and smooth packaging of
product. While selecting the manufacturing process it is
also essential to consider, that the product must reach to the
customer end within the specified period safely.
4 Application of graph theoretic approach
The single numerical index is resolute for selection of
suitable manufacturing process using graph theoretic
approach. As already discussed, the graph theoretic
approach has three steps as following:
1. Manufacturing process based digraph
2. Matrix representation of manufacturing process
3. Permanent function representation of manufacturing
process
4.1 Manufacturing process based digraph
A digraph (directed graph) is a graphical representation of
factors identified and interdependence between them. The
digraph carries nodes and edges. The nodes (Bi’s) represent
the factors identified and edges (bij’s) represent the inter-
action among different processes. Bi represents the inher-
itance of factors and bij represent the degree of dependence
of jth factor on ith factor. In the digraph bij is represented
as a directed edge from node i to node j. To show the
manufacturing process digraph, the four factors identified
are taken into consideration, i.e., Quality (B1), Cost (B2),
Technical Capability (B3), Production (B4). Based on the
interactions between the factors a digraph has been plotted
as shown in Fig. 4.
In the digraph represented above, the edges directed
from B1 to B2 and B2 to B1 shows that the nodes B1 and B2
are interdependent. It is obvious that good quality of
product may lead to increase the investments to maintain a
persistent quality level. These investments may increases
the cost of product. When the product cost is higher, it is
easy to maintain a proper quality level because due to
increased cost the manufacturers have sufficient funds to
maintain the quality level. Generally speaking, a higher
level product should be sold at a higher price due to more
costly or more extensive features (Freiesleben 2010). The
edges directed from B1 to B4 and B4 to B1 shows that nodes
B1 and B4 are also interdependent. Quality and production
control are vital activities for the profitability of modern
manufacturing companies, that are continuously facing
product specification and demand changes (Wiendahl et al.
2007). Quality control makes it possible to meet high
product quality standards, also reducing scraps and
reworks. Production control reduces the work in progress
(WIP) while meeting the target production rate (Colledani
and Tolio 2011).
The edge directed from B3 to B1 shows that node B1 is
affected by node B3. It is a proven fact that quality level of
any product can be raised by an effective and updated
Fig. 4 Manufacturing process based digraph
304 Int J Syst Assur Eng Manag (Oct-Dec 2011) 2(4):301–311
123
Technical Capability. In most circumstances, high perfor-
mance firms would have stronger capabilities as compared
to low performance firms (Yam et al. 2010). Technological
innovation capability is a comprehensive set of character-
istics of an organization that facilities and supports its
technological innovation strategies (Burgelman et al.
2004). They are a kind of special assets or resources that
include technology, product, process, knowledge, experi-
ence and organization (Guan and Ma 2003). The edge
directed from B3 to B4 shows that node B4 is affected by
node B3. The production of any organization is greatly
influenced by technical capabilities of the organization. As
the technical capabilities smoothness the production sys-
tem. If the technical capabilities of any organization are not
competent enough then, it is difficult for such organizations
to run the production system effectively. Due to rapid
technological change, high-tech industries typically require
a certain level of timely and dynamic strategy (Yasuda
2005).
The edges directed from B2 to B4 and B4 to B2 shows
that node B2 and node B4 are interdependent. To get good
quality production an organization needs good quality of
raw material, machinery, technology, skilled labour etc.
and all this leads to increase the cost of product. Also if the
production of product is not satisfying then rework or
rejection may lead to increase the cost. Higher product
variety leads to higher forecast errors, excessive inventory
for some products and shortages for others, higher over-
head and administrative costs, and higher manufacturing
costs due to more specialized processes, materials,
changeovers, and quality assurance methods (Lee and
Billington 1994). The edge directed from B2 to B3 shows
that node B3 is affected by node B2. As already discussed
between node B1 and B3, to enhance the quality of product,
it is essential to have effective and updated technical
capabilities. To get similar technical capabilities the cost of
product will increase due to the expense incurred in
upgrading and maintaining the technical capabilities.
The graphical representation of factors given through
the digraph is suitable for visual analysis. But it becomes
complex when a number of nodes in a given case (i.e., the
factors) increase. Moreover, it is not suitable for computer
processing. For this, the digraph is represented in matrix
form.
4.2 Matrix representation of manufacturing process
As already discussed in the previous section that the
graphical representation of factors is complex. So to reduce
the complexity of the digraph it is proposed to present a
manufacturing process digraph in the form of a matrix
which can be further resolved with the help of software.
The matrix of Manufacturing Process is an N 9 N
matrix, which considers all the factors (Bi’s) affecting the
manufacturing process and their relative interdependencies
(bij’s). The matrix representation of manufacturing process
is a one-to-one representation of the digraph. The matrix of
manufacturing process considering all the factors can be
represented as:
1 2 3 4 Factors
P1 ¼
B1 b12 b13 b14
b21 B2 b23 b24
b31 b32 B3 b34
b41 b42 b43 B4
0BBB@
1CCCA
1
2
3
4
ð2Þ
In the above mentioned matrix the diagonal elements
represents the inheritance of factors whereas the off-
diagonal elements represents the interaction between the
factors. The row of the matrix shows the inheritance of a
factor and its influence on other factors. And the column of
the matrix shows inheritance of factor and its dependency
on other factors. According to the digraph the
manufacturing process matrix can be represented as:
P1 ¼
B1 b12 0 b14
b21 B2 b23 b24
b31 0 B3 b34
b41 b42 0 B4
0BB@
1CCA ð3Þ
In the above matrix the some off-diagonal elements are
zero as there is no edge directed between them in the
manufacturing process digraph.
The value of off-diagonal elements can be determined
from Table 1 and to determine the value of diagonal ele-
ment, it is proposed to represent digraph for each factor
with their co-factors. The value of diagonal elements can
be determined through Table 2 also, but to get more pre-
cise value it is suggested to plot the digraph for each factor.
The value of diagonal elements can also be determined
by Table 2.
Now,
P1 ¼
B1 5 0 4
5 B2 4 3
4 0 B3 2
3 2 0 B4
0BB@
1CCA ð4Þ
4.3 Permanent function representation
To find out a single numerical index, the permanent of the
matrix, called as variable permanent quality function of
manufacturing process is used here. The permanent func-
tion is obtained in a similar manner as its determinant but
with keeping all signs positive. This expression is repre-
sents the rating of manufacturing process and contains all
possible quality terms of the manufacturing process. The
Int J Syst Assur Eng Manag (Oct-Dec 2011) 2(4):301–311 305
123
VPF expression corresponds to the four-characteristic
digraph/VPM is given as.
VPF ¼B1B2B3B4
þ b12b21B3B4 þ b13b31B2B4 þ b14b41B2B3
þ b23b32B1B4 þ b24b42B1B3 þ b34b43B1B2
þ b12b23b31B4 þ b13b32b21B4 þ b12b24b41B3
þ b42b21B3 þ b13b34b41B2 þ b14b43b31B2
þ b23b34b42B1 þ b24b43b32B1
þ b12b21b34b43 þ b13b31b24b42 þ b14b41b23b32
þ b12b23b34b41 þ b14b43b32b21 þ b13b34b42b21
þ b12b24b43b31 þ b14b42b23b31 þ b13b32b24b41
ð5Þ
4.4 Determination of value of diagonal elements
4.4.1 Quality based digraph
The factor B1, i.e., Quality is having three co-factors: low
defect rate (Q1), commitment to quality (Q2), improved
process capability (Q3) and to determine the interdepen-
dency between them, a quality based digraph is represented
as shown in Fig. 5.
To simplify the complexity of digraph shown in Fig. 5,
it is required to convert the digraph into a matrix as shown
in matrix 4.
B1 ¼Q1 q12 q13
q21 Q2 q23
q31 q32 Q3
0@
1A ð6Þ
B1 ¼4 4 0
5 3 4
3 3 4
0@
1A ð7Þ
The value of off-diagonal elements can be determined
through Table 1 and the value of diagonal elements can be
determined through Table 2.
To determine the value of factor B1, it is proposed to
find out the permanent function of the matrix using Eq. 1.
B1 ¼ 224
4.5 Cost based digraph
The factor B2, i.e., Cost is having three co-factors: pro-
cessing cost (C1), maintenance cost (C2), product cost (C3)
and to determine the interdependency between them, a cost
based digraph is represented as shown in Fig. 6.
Matrix representation of Cost based digraph is as
follows:
B2 ¼C1 c12 c13
c21 C2 c23
c31 c32 C3
0@
1A ð8Þ
B2 ¼4 0 4
0 4 3
0 0 3
0@
1A ð9Þ
So the permanent function of the matrix using Eq. 1 is
48, and,
B2 ¼ 48
4.6 Technical Capability based digraph
The factor B3, i.e., Technical Capability is having three co-
factors: Flexibility (T1), Efficiency (T2), Mechanism (T3)
Table 1 Value of interdependency of factors (Bij)
S. no. Qualitative measure
of interdependency
Assigned value
of factor
1 Very strong 5
2 Strong 4
3 Medium 3
4 Weak 2
5 Very weak 1
Table 2 Value of inheritance of factors (Bi)
S. no. Qualitative measure
of factor
Assigned value
of factor
1 Extremely low 1
2 Low 2
3 Below average 3
4 Average 4
5 Above average 5
6 High 6
7 Extremely high 7
Q1
Q2 Q3
Fig. 5 Quality based digraph
(B1)
C1
C2 C3
Fig. 6 Cost based digraph (B2)
306 Int J Syst Assur Eng Manag (Oct-Dec 2011) 2(4):301–311
123
and to determine the interdependency between them, a
Technical Capability based digraph is represented as
shown in Fig. 7.
Matrix representation of Technical Capability based
digraph is as follows:
B3 ¼T1 t12 t13
t21 T2 t23
t31 t32 T3
0@
1A ð10Þ
B3 ¼4 4 3
0 5 4
0 3 5
0@
1A ð11Þ
So the permanent function of the matrix using Eq. 1 is
148, and,
B3 ¼ 148
4.7 Production based digraph
The factor B4, i.e., Production is having three co-factors:
Production rate (P1), Packaging (P2), Delivery (P3) and to
determine the interdependency between them, a production
based digraph is represented as shown in Fig. 8.
Matrix representation of Technical Capability based
digraph is as follows:
B4 ¼P1 p12 p13
p21 P2 p23
p31 p32 P3
0@
1A ð12Þ
B4 ¼5 4 5
0 3 3
2 2 5
0@
1A ð13Þ
So the permanent function of the matrix using Eq. 1 is
159, and,
B4 ¼ 159
4.8 Permanent function representation
The single numerical index of the manufacturing process
matrix can be determined using Eq. 3 by filling the value of
factor B1, B2, B3 and B4 in matrix (3).
VPF ¼ 224� 48� 148� 159
þ 5� 5� 148� 159þ 0� 4� 48� 159
þ 4� 3� 48� 148þ4� 0� 224� 159þ 3� 2
� 224� 148þ 2� 0� 224� 48þ 5� 4
� 4� 159þ 0� 0� 5� 159þ 5� 3� 3� 148
þ 4� 2� 5� 148þ 0� 2� 3� 48þ 4� 0� 4
� 48þ 4� 2� 2� 224þ 3� 0� 0� 224
þ 5� 5� 2� 0þ 0� 4� 3� 2þ 4� 3� 4� 0
þ 5� 4� 2� 3þ 4� 0� 0� 5þ 0� 2� 2� 5
þ 5� 3� 0� 4þ 4� 2� 4� 4þ 0� 0� 3� 3
VPF ¼ 253917656
5 An illustrative example
To exhibit the proposed methodology, an example is taken
considering mass production of a mild steel cylindrical bar
of [ 20 mm and length 50 mm. For manufacturing the
cylindrical bar, three different manufacturing methods are
proposed as following:
I. CNC lathe
II. Casting
III. Extrusion
The following assumptions have been made to manu-
facturing process:
1. All the necessary machinery and equipments required for
each manufacturing process mentioned above is available
within the Industry, no further investment is required.
2. The cylindrical bar can be produced from any of the
manufacturing process, as there is no any restriction
from the customer end. So the required bar can be
produced from any of the process.
3. All Technical capabilities and expertise required for each
manufacturing process are available within the Industry.
6 Identification of attributes for selection
of manufacturing process
To select the best manufacturing process among three
manufacturing methods, it is necessary to identify the
T1
T2 T3
Fig. 7 Technical Capability
based digraph
P1
P2 P3
Fig. 8 Production based
digraph
Int J Syst Assur Eng Manag (Oct-Dec 2011) 2(4):301–311 307
123
Table 3 Application of graph theoretic approach
308 Int J Syst Assur Eng Manag (Oct-Dec 2011) 2(4):301–311
123
Table 3 continued
Int J Syst Assur Eng Manag (Oct-Dec 2011) 2(4):301–311 309
123
attributes affecting the manufacturing process significantly.
The attributes and their co-factors affecting the selection of
manufacturing process are as following:
1. Quality—low defect rate, less scrap and wastage,
commitment to quality
2. Cost—processing cost, maintenance cost, product cost
3. Production—time taken per piece, packaging, system
complexity
7 Application of graph theoretic approach
To identify the single numerical index for the selection of
best manufacturing, the graph theoretic approach is applied.
The graph theoretic approach has following three steps:
• Digraph representation
• Matrix representation
• Permanent function representation
The digraph representation and matrix representation for
all the three processes taken here will remain same but
values will differ accordingly from process to process.
Table 3 represents the application of graph theoretic
approach for the selection of best process among three
processes, i.e., CNC Lathe, Casting and Extrusion.
The Permanent function representation of the different
processes which reveals a single numerical index for the
selection of best process are as following:
Process I CNC Latheð Þ ¼ 674168
Process II Castingð Þ ¼ 4052
Table 3 continued
310 Int J Syst Assur Eng Manag (Oct-Dec 2011) 2(4):301–311
123
Process III Extrusionð Þ ¼ 107910
The above calculations shows that production of a mild steel
cylindrical bar through Process I (CNC Lathe) is much better
and effective process than other processes as the permanent
function is 674168 which is higher than the permanent function
of Process II (Casting) and Process III (Extrusion)
8 Conclusions
The paper shows methodology for selecting best feasible
manufacturing process in general using graph theoretic
approach which reveals a single numerical index. The
index is helpful in assessing the best manufacturing pro-
cess. The factors/attributes chosen for the selection and
assessment of best manufacturing process are Quality,
Cost, Technical Capability, Production. A fishbone dia-
gram is drawn to represent the factors and co-factors which
affects the selection of manufacturing process. The graph
theoretic approach is divided into three stages namely:
digraph representation, matrix representation and perma-
nent function representation. Digraph representation is a
graphical representation of identified factors and interde-
pendence between them. As the digraph is a visual repre-
sentation and it seems complex with higher number of
factors, So to reduce the complexity, the digraph is con-
verted into a matrix. To find out a single numerical index,
the permanent of the matrix, called as variable permanent
quality function of manufacturing process is determined.
To determine the value of factors, i.e., B1 (Quality), B2
(Cost), B3 (Technical Capability) and B4 (Production),
digraphs are drawn for each factor so that precise values of
the factors can be determined.
An example is also explained for understanding the
application of graph theoretic approach. In this example,
three processes (i.e., CNC Lathe, Casting, Extrusion) are
mentioned for mass production of a mild steel cylindrical bar
of [ 20 mm and length 50 mm. The attributes chosen for the
selection of best process are Quality, Cost and Production.
The result shows that permanent function representation of
CNC lathe process is 674168 which is higher than the per-
manent function of casting and extrusion process. So, the
results proves that the CNC lathe process is much better and
effective process than casting and extrusion process.
References
Best M (2001) The new competitive advantage. Oxford University
Press, Oxford
Burgelman R, Maidique MA, Wheelwright SC (2004) Strategic
management of technology and innovation. McGraw Hill, New
York
Chien-Wei Wu, Pearn WL, Kotz S (2009) An overview of theory and
practice on process capability indices for quality assurance. Int J
Prod Econ 117(2):338–359
Colledani M, Tolio T (2011) Joint design of quality and production
control in manufacturing systems, J Manuf Sci Technol 4(3):
281–289
Ernst RG (1987) How to streamline operations. J Bus Strateg 8(2):
32–36
Field F, Kirchain R, Roth R (2007) Process cost modeling: strategic
engineering and economic evaluation of materials technologies.
J Miner Met Mater Soc 59(10):21–32
Freiesleben J (2010) Proposing a new approach to discussing
economic effects of design quality. Int J Prod Econ 124(2):
348–359
Fuchs ERH, Bruce EJ, Ram RJ, Kirchain RE (2006) Process-based
cost modeling of photonics manufacture: the cost competitive-
ness of monolithic integration of a 1550-nm dfb laser and an
electroabsorptive modulator on an inp platform. J Lightwave
Technol 24(8):3175–3186
Fuchs ERH, Field FR, Roth R, Kirchain RE (2008) Strategic materials
selection in the automobile body: economic opportunities for
polymer composite design. Compos Sci Technol 68(9):1989–2002
Guan J, Ma N (2003) Innovative capability and export performance of
Chinese firms. Technovation 23:737–747
Jahazi M, Hossein-Nejad S (2004) The development of an optimum
manufacturing and material selection process for the fabrication
of labyrinth seal strips. J Mater Process Technol 152(3):272–275
Johnson M, Kirchain R (2009) Quantifying the effects of parts
consolidation and development costs on material selection deci-
sions: a process-based costing approach. Int J Prod Econ 119:
174–186
Lee HL, Billington C (1994) Designing products and processes for
postponement. In: Dasu S, Eastman C (eds) Management of
design. Kluwer, Boston, pp 105–122
Narsingh D (2000) Graph theory with application to engineering and
computer science. Prentice Hall of India, New Delhi
Perzyk M, Mefta OK (1998) Selection of manufacturing process in
mechanical design. J Mater Process Technol 76:198–202
Robinson DF, Foulds LR (1980) Digraph: theory and techniques.
Gordon and Breach Science, London
Ruffo M, Tuck C, Hague R (2006) Cost estimation for rapid
manufacturing—laser sintering production for low to medium
volumes. Proc Inst Mech Eng B 220(9):1417–1427
Sarker BR, Jamal AMM, Mondal S (2008) Optimal batch sizing in a
multi-stage production system with rework consideration. Eur J
Oper Res 184(3):915–929
Shehab EM, Abdalla HS (2001) Manufacturing cost modelling for
concurrent product development. Robotics Comput Integr Manuf
17(4):341–353
Singer A (2004) NEMI cost analysis: optical versus copper
backplanes (Part 1: Benchmarking Copper), presented by Adam
Singer, Cookson Electronics, for Jack Fisher, APEX 2004,
February 26, 2004 (Anaheim, CA).
Tewari M, Goebel J (2002) Small firm competitiveness in a trade
liberalized world: lessons for Tamil Nadu. Global Development
Network, New Delhi
Wiendahl H-P, ElMaraghy HA, Nyhuis P, Zah MF, Wiendahl H–H,
Duffie N, Brieke M (2007) Changeable manufacturing—classi-
fication, design and operation. CIRP Ann Manuf Technol 56(2):
783–809
Yam RCM, Lo W, Tang EPY, Antonio KWL (2010) Technological
innovation capabilities and firm performance, world academy of
science. Eng Technol 66:1023–1031
Yasuda H (2005) Formation of strategic alliances in high-technology
industries: comparative study of the resource-based theory and
the transaction-cost theory. Technovation 25(7):763–770
Int J Syst Assur Eng Manag (Oct-Dec 2011) 2(4):301–311 311
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