International Journal of Scientific & Engineering Research Volume 2, Issue7, july-2011 1
ISSN 2229-5518
Improving Cost Efficient Manufacturing unit by Considering unit facility and Supplier Routing Cost in Supply Chain
S . Shakeel ahamed , Dr.G. Ranga Janardhana , Dr.E.L.Nagesh
—————————— • ——————————
lobal competition, shorter product life cycles, dynamic changes of demand patterns and product varieties and environmental standards frequently cause significant changes in market scenario compelling manufacturing enterprises to supply their best in order to survive [5]. Considerable stress is placed on their supply chains by this change that demands for an improved coordination of the performed actions and supply chain management techniques that can concurrently improve the customer service and reduce the cost are available for companies [6]. Supply chain (SC)
management is a network of
organizations, people, activities, information and resources and it is engaged in the physical flow of products from supplier to customer [4]. Nowadays, inventory management is considered as an important field of Supply chain management [2]. Maintaining the cost efficiencies while transporting the right product to the right place at the right time is the basic objective of supply chain management [10]. Inventory is a reserve of goods preserved for meeting future demand. Determining appropriate ordering time and
ordering quantity is the objective of inventory management. Typical supply chain configuration decisions include identifying location for production and distribution facilities, choosing supplier and creating links between the supply chains units [13]. Several
manufacturing companies use a production
inventory system to manage changes in
demand of the consumers for the product. A
completed goods warehouse to store products
that are not sold immediately after production
and a manufacturing plant exists in such systems [8]. The material handling and storage system greatly influence the performance of any manufacturing company .Routing has emerged as one of the most significant kinds of supply chain management, because it is one of the most crucial elements in managing the global supply chain. Companies are compelled to constantly search for ways to improve their operations by the characteristics of the present competitive environment for example the rapidity with which products are designed, produced and delivered, in addition to the requirement for superior efficiency and lower operational expenses (30). One of the difficult to optimally solve combinatorial optimization problems is the inventory-routing problem (27). Identifying a distribution strategy that
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decreases long term distribution costs is the objective of inventory routing problem (IRP) (29).
Finding the best reordering point and
best ordering quantity according to the facility
of the manufacturing unit is an important
factor which avoids the over ordering and
lack ness in product storage. The prior
research of the author [] finds the optimized reorder point and the ordering quantity of the manufacturing unit which develops the sample best chromosome as in table:1. The proposed research improves the prior research
. In this research we improve the ordering
quantity according to the facility of the manufacturing unit by finding the facility
agreeable efficient solution demand matrix using
by finding capacity agreeable efficient solution demand matrix. In the real time, the shipment department in each supplier plant considers the factors like delay cost, path cost and transportation cost. The decision of choosing the best supplier providing the minimum routing cost for the required raw materials is the challenging feature for the inventory control of the manufacturing unit. The proposed system also finds the best routed supplier with minimum routing cost.
demand rate of each raw material for the preceding M period is forecasted to determine the optimized amount of order and optimized reorder point of ‘ MN ’ for the period of M = {M 1 , M 2 , M k } ;1 < k 5; 12 . Let
Genetic algorithm. This research also finds the best routed supplier for ordering the products.
D1 = {D1
i = 1, , R
; 1 <
j 5; M } be
Let ‘ MN ’ be the manufacturing system which
the forecasted demand rate for each material
uses the raw
in R , where
D1ij
is the predicted demand for
materials R = {R1 , R2 , R3 ....Rn }for
the ith
raw material for the jth
month forecasted
production and these raw materials are shipped from the suppliers S = {S1 , S 2 , S3 ....S n } . The
using the observed historical data.
the ith month. The generated ordering quantity in the solution demand matrix is tuned to be efficient by using the holding capacity ‘ C ’ of the
he forecasted demand rate
D1 is used to create
manufacturing unit. The Pseudocode-1
the associated solution demand matrix
represents the process of finding the capacity
D2 = {D2
D2ij
< N max
; i = 1, , | R |;1 <
j 5;
M a}greeable efficient solution demand matrix.
The generated solution demand matrix and the
consisting of the forecasted solution demands for
each raw material for the interval M ,
maximum holding capacity of the manufacturing unit is given as input to the procedure. The sum
where N max
= Max(D1) + 0.20 x Max(D1)
of ordering quantity of every positive order and
. The arbitrarily created solution demand rate for
the number of positive orders are calculated. If
the sum of ordering quantity for a month in the
each raw material is smaller than Nmax
and each
demand solution matrix is greater than the
row of the connected solution demand matrix
capacity of the manufacturing unit then the
yields the likely ordering amount of each raw material in R . From the solution demand matrix
ordering quantity is adjusted by the
Re j value
D2 the efficient solution demand matrix
so that it can satisfy the holding capacity.
Eventually, we obtain �D2ij , an efficient
�D2 = {�D2 �D
= D2
- Re
; if
D2 > C ; i = 1, , | R |;1 <
j 5; M }
ij ij ij j
D2ij
ij solution matrix that can satisfy the capacity of the
manufacturing unit.
where
Reij =
Cnt
is the reduction
amount and Cnt is the no of positive orders in
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Input : Solution Demand matrix D2 , Maximum Holding capacity C
Output : The Resultant Solution demand matrix �D2 with facility
M k -7Months
D2( ki )
Re j
Pseudocode:
-7 Ordering quantity of ith raw material for the kth month.
-7 Reducing amount
For each M k M
Set S k =
D2
th
Set count k =
no of positive order for k
month
Set Re k
= S k
/ count k
For each
D2ki
If positive order and S k > C
End If
End For
�D2 ki
= D2 ki - Re k
The manufacturing unit ‘ MN ’ purchases the
‘Supplier-2’ may have the cost ‘C2’ which is greater than ‘C1’.The Table -1 illustrates the
raw materials
' R'
from the supplier
' S '
that
sample best chromosome which represents the
are needed for production .Each supplier has the different routing cost for shipping the product from the supplier plant to the manufacturing unit. The same raw material may have the different routing cost among the various suppliers. For example for the raw material ‘R1’ the ‘Supplier-1’ may fix the cost ‘C1’ where the
optimized reorder point of the raw materials for
the ‘M’ months. The table1 represents that the raw materials to be purchased for the month ‘M1’ is ‘R1,R4,R9,R10’. The ‘1’ in the table illustrates the positive ordering status of the raw material and ‘0’ represents the negative ordering status of the raw material.
R1 | R2 | R3 | R4 | R5 | R6 | R7 | R8 | R9 | R10 | |
M1 | 1 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 1 | 1 |
M2 | 1 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 1 |
M3 | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 1 |
M4 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 1 |
M5 | 1 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
M6 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 0 |
M7 | 0 | 0 | 1 | 0 | 0 | 0 | 1 | 0 | 0 | 1 |
M8 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
M9 | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 0 |
M10 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 1 |
M11 | 0 | 0 | 1 | 0 | 0 | 0 | 1 | 0 | 0 | 0 |
M12 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 |
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Let
PRki ; i = 1..10 be the set of the raw materials
combination list of supplier having the minimum routing cost is found out first and among ‘n’
to be purchased for the kth month, where
k=1..12, SC ={SCi ; i =1..S
} be the set of raw materials that are supplied by the each supplier
combination the combination having the
minimum routing cost is selected for the first month. This process is repeated for every month
and the supplier list �S
with minimum routing
where
SCi
= { R j
|; j
1..10}
is the raw
cost for the required raw material is generated.
materials supplied by the ith supplier and
RC = {RCij
|; j
1..10} is the routing cost of
the raw materials supplied by the ith supplier.
For example, from the table1 the raw materials to
be purchased for | the | 1st | month | is |
R1, R4, R9, R10 . | The |
DA = {DAi
|; i
1..10}is the combination of
the raw materials supplied by the supplier with their routing cost are separated and stored according to their length wise.
The Pseudo code 2 below represents the steps
used for finding the best routing supplier. From the best chromosome, the raw material list to be purchased for a month is identified and their each combination list is generated. The ‘n’
Input : Best Chromosome BC , The raw materials supplier by the Suppliers
SC, RC the routing cost of the raw materials supplied by the supplier, DAr the combination database.
with minimum routing cost for the required raw material.
M k -7 Months
PRk -7 Purchasing raw material
PRcombi
-7 Combination list of purchasing raw material
Pseudo code:
For each M k M
Get PRk
Generate PR
combi
Set l = length(PRk )
Randomly select r < l
For each i 5; r
Sel = r length data in PR
If Sel exist in DAr
RCost = RCr
Endif
SS = min (Rcost)
RR = DAr (min (Rcost))
r=r-1
combi
End for
End for
�S = �S + RR
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sample best chromosome having the optimized reorder point for ordering the raw materials.
R1 | R2 | R3 | R4 | R5 | R6 | R7 | R8 | R9 | R10 | |
M1 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 1 | 0 | 0 |
M2 | 1 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
M3 | 0 | 1 | 0 | 0 | 0 | 1 | 0 | 1 | 0 | 0 |
M4 | 0 | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 0 |
M5 | 0 | 0 | 1 | 1 | 0 | 1 | 1 | 0 | 0 | 0 |
M6 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
M7 | 0 | 0 | 1 | 0 | 0 | 0 | 1 | 0 | 1 | 0 |
M8 | 0 | 0 | 0 | 1 | 1 | 0 | 1 | 0 | 0 | 0 |
M9 | 0 | 0 | 1 | 0 | 0 | 0 | 1 | 0 | 0 | 1 |
M10 | 1 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 1 |
M11 | 0 | 0 | 0 | 1 | 0 | 1 | 0 | 0 | 0 | 0 |
M12 | 1 | 0 | 0 | 0 | 1 | 0 | 0 | 1 | 0 | 0 |
Mont h | Raw materials to be purchased |
M1 | R2,R3,R8 |
M2 | R1,R4 |
M3 | R2,R6,R8 |
M4 | R5,R6 |
M5 | R3,R4,R6,R7 |
M6 | R1,R2 |
M7 | R3,R7,R9 |
M8 | R4,R5,R7 |
M9 | R3,R7,R10 |
M10 | R1,R5,R10 |
M11 | R4,R6 |
M12 | R1,R5,R8 |
From the table 2 the raw materials to be purchased are identified by their values and table 3 represents the purchasing list of the raw materials to be purchased for the whole period. The raw materials which are supplied
by the supplier are listed and their combination with the routing cost is stored in the database according to their length wise.
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Supplier | Combination | Routing cost |
1 | 2 | 75 |
1 | 3 | 84 |
1 | 9 | 40 |
1 | 7 | 10 |
1 | 1 | 27 |
2 | 5 | 58 |
2 | 6 | 100 |
2 | 4 | 37 |
3 | 8 | 18 |
3 | 10 | 88 |
3 | 2 | 28 |
3 | 3 | 85 |
3 | 9 | 81 |
3 | 7 | 19 |
3 | 1 | 98 |
The table 4 represents the sample raw material list supplied by the suppliers which are arranged by their length. The Raw materials to be purchased for the
month ‘M1’ is chosen first also the combination of the purchasing list are generated. The table 5 illustrates the combination list of the materials.
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Sno | Combination |
1 | R2 |
2 | R3 |
3 | R8 |
4 | R2,R3 |
5 | R2,R8 |
6 | R3,R8 |
7 | R2,R3,R8 |
The count of the raw materials to be purchased is found out first. In our example the count of the raw materials to be purchased for the first month is ‘l=3’. Randomly choose a number less than ‘l’ for choosing the supplier list. If the randomly choose number is 2 then the occurrence of the two length combination in the purchasing list is searched in the two length supplier list. It is occurs then the corresponding routing cost ‘RR’ is selected and stored, then the all the ‘1’ length combination item in the purchasing
list is searched in the 1 length supplier list
and their routing cost is found out and finally a best combination represents the supplier list to be chosen are found. The above steps are repeated ‘n’ times to get ‘n’ combination of the supplier list. From the
‘n’ combination, the best combination having the minimum routing cost is selected for the first month. Like wise the best combination are chosen for the each month in the whole period. The best combination supplier list, corresponding routing cost and minimized total routing cost for the dataset -1, are illustrated in table-6(a).
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2 3 => 5 => 39
8 => 4 => 36
1 | => | 4 => | 46 |
4 | => | 5 => | 44 |
2 => 3 => 67
6 8 => 2 => 55
5 | => | 4 => 53 |
6 | => | 4 => 63 |
3 4 => 2 => 56
6 => 4 => 63
7 => 2 => 36
1 | => | 4 => | 46 |
2 | => | 3 => | 67 |
3 | => | 5 | => | 30 |
7 | => | 2 | => | 36 |
9 | => | 3 | => | 3 |
4 | => | 5 | => | 44 |
5 | => | 4 | => | 53 |
7 | => | 2 | => | 36 |
3 | => | 5 => | 30 |
7 10 => 5 => 70
1 | => | 4 | => | 46 |
5 | => | 4 | => | 53 |
10 | => | 2 | => | 43 |
4 => 5 => 44
6 => 4 => 63
1 => 4 => 46
5 8 => 4 => 42
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The performance of the proposed approach is evaluated using different data set. The performance is evaluated by comparing the total routing cost given by the recommended suppliers by the proposed method with the routing cost of the non recommend suppliers. The figure(a) represents the comparison graph of the routing cost of the recommend suppliers with the routing cost of the non recommendedsuppliersfordataset-1,
The figure-(a) below illustrates that the routing cost of the suppliers recommend by the proposed method is less than the routing cost of the non recommended suppliers.
Inventory management is fundamentally related to specification of the quantity and placement of stocked goods. Safeguarding the normal and forecasted course of production against the arbitrary disturbance of running out of materials or goods necessitate inventory management at several locations within a facility or within multiple locations of a supply network. Selection of the least cost, distance, and time route from diverse choices for a good decision to arrive at its destination is called routing. Inventory routing problems in which inventory control and routing decisions are to be made at the same time is one of the more significant and more challenging extensions of vehicle routing problems. It can be used for the management of storage capacity for raw materials in manufacturing units. The proposed system improves the prior research of the author by finding the facility agreeable solution demand matrix and also this research finds the best routed supplier having the minimum routing cost.
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.s.shakeel ahamed is presently pursuing his phd degree program in mechanical engineering at jntu Hyderabad, Email:shakeelkdp@gmail.com.
.Dr.G.Rangajanardhana is working as principal,jntu kakinada vijayanagaram campus. A.P India. Email:ranga.janardana@gmail.com.
Dr.E.L.Nagesh is working as principal netaji institute of engineering and tecnology Hyderabad. India. Email:el.nagesh@gmail.com
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