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Supply Chain Management in a Dairy
Industry – A Case Study
K. Venkata Subbaiah , Member, IAENG, K. Narayana Rao K. Nookesh babu
ABSTRACT - Supply chain management is the plan and
control of material and information flow among
suppliers, facilities, warehouses and customers with the
objectives of minimization of cost, maximization of
customer services and flexibility. The supply chain of a
business process comprises mainly five activities viz.,
Purchase of materials from suppliers, transportation of
materials from suppliers to facilities, production of
goods at facilities, transportation of goods from
facilitates to ware houses and transportation of goods
from ware houses to customers.
In this paper, a supply chain model is developed for a
dairy industry, located in Andhra Pradesh, India. The
supply chain includes four echelons namely raw milk
suppliers, plant, warehouse and customers. In this
model, emphasis is mainly on production and
distribution activities, with a view to find out purchase
plan of raw milk, production plan of product mix and
transportation plan of the products.
Index Terms- Supply chain management,
Transportation, Production plan, Customer zones.
I. INTRODUCTION
Supply chain management (SCM) is a
rapidly evolving area of interest to academicians and
business management practitioners alike.
Coordinating the external and internal activities of a
firm is the basic philosophy of supply chain
management. It is about managing the entire process
in a collective and unified fashion.
Most of the manufacturing firms are
organized as networks of manufacturing and
distribution facilities that procure raw materials
transform them into intermediate and finished
K. Venkata Subbaiah is with Department of Mechanical
Engineering, Andhra University, Visakhapatnam, India.
Phone: +91-891-2536486 (R), +91-09848063452 (M)
e-mail: drkvsau@yahoo.co.in
K. Narayana Rao is with Department of Mechanical
Engineering, Government Polytechnic, Visakhapatnam.
K.Nookesh babu is with Department of Mechanical
Engineering, Andhra University, Visakhapatnam.
products and distribute the finished products to
customers. The simplest network consists of facilities
which perform procurement, manufacturing and
distribution. These networks are called value added
chains or supply chains.
A supply chain consists of all stages involved
directly or indirectly in fulfilling a customer request.
The supply chain not only includes the manufactures
and suppliers but also retailers and customers
themselves with in each organization.
A supply chain is an integrated system
wherein a number of various business entities (i.e.
suppliers, manufacturers, industrial customers,
distributors, retailers) work together to address issues
of both materials flow and information flow. A
reference model - the Supply Chain Operations
Reference model (SCOR), has been developed by the
Supply-Chain Council (SCC) [1]. This process
reference model contains standard description of
management process and a framework of relationships
among the standard processes. Ganeshan et.al. [5]
explored the basics of supply chain management from
a conceptual perspective by tracing the roots of the
definition and the origins of the concept from a broad
stream of literature. Pyke and Cohen [6] analyzed the
management of materials in an integrated supply chain
and develop a markov chain model for a three level
production distribution system. Cohen and
Huchzermeier [3] presented a survey of the literature
pertaining to analytic approaches for global supply
chain strategy analysis and planning. The integrated
supply chain network model is developed to capture
the complexities of a multi-product, multi-echelon,
multi-country, multiperiod planning problem for the
optimal choice of facility locations, capacity and
technology used. Sabri and Beamon [4] developed an
integrated supply chain model for use in simultaneous
strategic and operation supply chain planning. .Lee and
Kim [7] proposed a hybrid approach to solve
production and distribution problems in supply chains.
Thomas and Griffin [8] define the categories of
operational co ordination, buyer and vendor,
production and distribution, inventory and distribution.
Arntzen et.al [9] provide the most comprehensive
Proceedings of the World Congress on Engineering 2009 Vol I
WCE 2009, July 1 - 3, 2009, London, U.K.
ISBN: 978-988-17012-5-1
WCE 2009
deterministic model for supply chain management
with an objective function containing the cost and
time elements. Even though supply chain
management is relatively new, the idea of co-ordinate
planning is not new. The study of multi-echelon
inventory/distribution systems began as early as 1960
by Clark and Scarf [2]. Since then many researchers
have investigated multi echelon inventory and
distribution systems. Less research has been aimed at
co-ordination of procurements, production and
distribution systems. In this paper an attempt has
been made to develop a coordinated supply chain-
planning model with procurement, production and
distribution systems.
II. MODEL FORMULATION
The proposal of the model is to find an optimal
strategic plan for an integrated supply chain model.
Notations
MCtvp Cost of material p purchased by
vendor v at time t
PCtfg Production cost of goods g produced
by facility f at time t
VFTCtvp Transportation cost of material p
Transported from vendor v to
facility f at time t
FWTCtfwg Transportation cost of goods g
transported from facility f to ware
house w at time t
WZTCtwcg Transportation cost of goods g
transported from ware house w to
customer location c at time t
FMICtfp Inventory cost of mterial p
of facility f at time t
FGICtfg Inventory cost of goods g
of facility f at time t
WICtwg Inventory cost of goods g of
warehouse w at time t
BOMgp Amount of material p needed for
producing goods g
AVtvp The amount of material p
purchased by vendor v at time t
Rtvfp The amount of material p which
vendor v Transported of facility f at
time t.
AFtfp The inventory of material p in the
facility f at time t
Rtfg Amount of good g which facility f
produced at time t
AFtfg The inventory of goods g at facility
f at time t.
Rtfwg The amount of goods g which
facility f transported to ware house
w at time t.
AWtwg The inventory of good g in the
ware house w at time t.
Rtwcg The amount of good g which ware
house w transported to
customer c at time t.
ACtcg The demand of goods g by
customer c at time t.
Assumptions
1. Capacities of vendors are fixed.
2. Demand is deterministic.
3. Variable cost per unit production is constant
Mathematical model
This model consists of four echelons namely
Suppliers, Plants, Distribution Centers (DCs), and
Customer zones (CZs).
A multi-objective function is formulated to
minimize cost subject to supplies, plant and
distribution capacities, production and distribution
through put limits and customs demand requirements.
Total cost includes fixed costs of production and
distribution, variable costs of production, distribution
and transportation.
Various costs involved in the supply chain are
1. Material Cost = tvp
AV
tvp
vpMC *
∑
2. Production cost = tfg
R
tfg
fgPC *
∑
3. Transportation cost =
** *VFTC R FWTC R WCTC R
twcg twcg
tvfp tvfp tfwg tfwg
vfp fwg wcg
∑∑ ∑
++
4. Inventory cost =
***
tfp tfg twg
FMIC AF FGIC AF WIC AWtwg
tfp tfg
ft fg wg
∑∑ ∑
++
The objective function of the model is to minimize the
total cost associated with the supply chain which
includes material, production, transportation and
inventory costs.
Minimize Z=
** *
***
**
tfp
tfg twg
MC AV PC R VFTC R
tvp tvp tfg tfg tvfp tvfp
vsp fg vfp
F
WTC R WCTC R FMIC AF
twcg twcg
tfwg tfwg tfp
fwg wcg ft
FGIC AF WIC AWtwg
tfg
fg wg
∑∑∑
++
∑∑∑
++ +
∑∑
++
Proceedings of the World Congress on Engineering 2009 Vol I
WCE 2009, July 1 - 3, 2009, London, U.K.
ISBN: 978-988-17012-5-1
WCE 2009
The above stated problem is solved subjected to the
following constraint set.
1. Upper – Lower bound restrictions
0 ≤ Rtvfp ≤ Rtvfp _ UPbound
0 ≤ Rtfwg ≤ Rtfwg _ UPbound
0 ≤ Rtwcg ≤ Rtwcg _ UPbound
Rtfg _ LPbound ≤ Rtfg ≤ Rtfg _ UPbound
etvf =1; ettw =1; etvc=1;
2. Flow Conservative restrictions
,,
tvfp tvp
t
R
LV t v p=∀
∑
() *
vf
tfp t et vfp gp tfg
vg
A
FR BOMR
−
+−
∑∑
(1) ,,
tfp
A
Ftfp
+
=∀
() (1)
,,
fw fwg twcg
twg t et t wg
fc
AW R R AW
twg
−+
+−=
∀
∑∑
() ,,
wc
tet wcg tcg
w
R
AC t c g
−=∀
∑
III. CASE STUDY
The above developed model is applied to Visakha
Dairy situated in Andhra Pradesh, India. The above
dairy has six vendors located at Vsiahapatnam,
Vizianagaram, Tuni, Ramabadrapuram, Narsipatnam
and Srikakulam. It has two facilities located at
Visakhapatnam and kakinada to meet the customer
demands. Five warehouses are situated at
Visakapatnam, Vizianagaram, Srikakulam Kakinada
and Rajahmundry. Its customer locations are situated
at Visakhapatnam, Vizianagaram, Srikakulam,
Kakinada and Rajamundry.
The input data required for the design of supply chain
for the above stated industry is given below.
Input Data
Material Cost
v
p
1 2 3 4 5 6
1 1140 1160 991 1135 872 1056
Vendor to facility transportation cost
v
f
1 2 3 4 5 6
1 3.26 26.33 36.24 28.56 84.8 33.35
2 32.98 6.02 66.24 55.56 103.8 3.26
Facility to ware house transportation cost
For facility1
g
w
1 2 3 4 5 6
1 3.26 3.26 3.26 3.26 3.26 3.26
2 11.9 11.9 11.9 11.9 11.9 11.9
3 13.6 13.6 13.6 13.6 13.6 13.6
4 8.9 8.9 8.9 8.9 8.9 8.9
5 7.56 7.56 7.56 7.56 7.56 7.56
For facility 2
g
w
1 2 3 4 5 6
1 10.9 10.9 10.9 10.9 10.9 10.9
2 4.52 4.52 4.52 4.52 4.52 4.52
3 3.26 3.26 3.26 3.26 3.26 3.26
4 19.8 19.8 19.8 19.8 19.8 19.8
5 18.4 18.4 18.4 18.4 18.4 18.4
Ware House to customer transportation cost
c
w
1 2 3 4 5
1 0 11.9 13.16 8.9 7.56
2 13.26 0 1.26 3 4.1
3 9.96 1.3 0 4.26 5.56
4 6.74 3 4.26 0 1.24
5 4.3 4.34 5.36 1.24 0
In the above table the transportation cost for good 1 is
shown and the same table repeats for the remaining
goods.
Inventory carrying cost at the facility for the raw
material and goods are considered as Zeros.
Inventory const at warehouse
g
w
1 2 3 4 5 6
1 0.07 0.05 0.07 0.05 0.07 0.05
2 0.07 0.05 0.07 0.05 0.07 0.05
3 0.07 0.05 0.07 0.05 0.07 0.05
4 0.07 0.05 0.07 0.05 0.07 0.05
5 0.07 0.05 0.07 0.05 0.07 0.05
Proceedings of the World Congress on Engineering 2009 Vol I
WCE 2009, July 1 - 3, 2009, London, U.K.
ISBN: 978-988-17012-5-1
WCE 2009
Capacities of Vendors (in thousands)
v
p
1 2 3 4 5 6
1 178 43 325 45 22 20
Capacities of facilities for producing different goods
g
f
1 2 3 4 5 6
1 25000 11000 7500 4000 4000 32000
2 4000 15000 0 150 4000 30000
Capacities of ware house to hold different products
g
w
1 2 3 4 5 6
1 25000 100000 7000 3000 4000 25000
2 1500 5000 0 0 1000 20000
3 1500 4000 0 500 2000 8000
4 1000 3000 0 0 1000 6000
5 0 500 500 500 300 5000
Demands for different goods at different customer
locations
g
c
1 2 3 4 5 6
1 23760 10903 7000 3199 3624 23726
2 1072 4624 0 0 304 16684
3 1254 3564 0 106 2076 7352
4 962 3234 0 0 806 6210
5 0 195 0 158 193 4659
The Problem is solved using LINGO student version
package.
IV. RESULTS AND DISCUSSIONS
The optimal solution for the model is
Table I: Quantities of material to be procured version
different vendors.
v
p
1 2 3 4 5 6
1 106565 43000 32500 0 22000 29000
Table II: Quantities of goods transported from vendors
to facilities
v
f
1 2 3 4 5 6
1 106565 9850 32500 0 22000 0
2 0 33150 0 0 0 29000
Table III: Amounts of goods produced at both the
facilities
g
f
1 2 3 4 5 6
1 23048 105920 7000 3313 2003 28631
2 4000 1500 0 150 4000 3000
Table IV: Amounts of goods transported from facilities
to warehouse
From Facility F1
g
w
1 2 3 4 5 6
1 23048 105920 7000 3199 3003 23726
2 0 0 0 0 0 0
3 0 0 0 0 0 0
4 0 0 0 0 0 0
5 0 0 0 114 0 4905
From Facility F2
g
w
1 2 3 4 5 6
1 712 3383 0 0 621 0
2 1072 4819 0 44 497 16684
3 2216 6798 0 106 2882 13316
4 0 0 0 0 0 0
5 0 0 0 0 0 0
Table V: Amounts of goods to be transported from
ware houses to customer Zones.
From ware house 1
g
c
1 2 3 4 5 6
1 23760 109303 7000 3199 3624 23726
2 0 0 0 0 0 0
3 0 0 0 0 0 0
4 0 0 0 0 0 0
5 0 0 0 0 0 0
Proceedings of the World Congress on Engineering 2009 Vol I
WCE 2009, July 1 - 3, 2009, London, U.K.
ISBN: 978-988-17012-5-1
WCE 2009
From Ware House 2
g
c
1 2 3 4 5 6
1 0 0 0 0 0 0
2 1072 4624 0 0 304 16684
3 0 0 0 0 0 0
4 0 0 0 0 0 0
5 0 195 0 44 193 0
From ware house 3
g
c
1 2 3 4 5 6
1 0 0 0 0 0 0
2 0 0 0 0 0 0
3 1254 3564 0 106 2076 7352
4 962 3234 0 0 806 5964
5 0 0 0 0 0 0
From ware house 5
g
c
1 2 3 4 5 6
1 0 0 0 0 0 0
2 0 0 0 0 0 0
3 0 0 0 0 0 0
4 0 0 0 0 0 246
5 0 0 0 114 0 4659
Table I represents the procurement plan which
indicates quantities of raw materials to be procured
from different vendors. As both the material cost and
transportation costs to both the facilities is high from
vendor 4 (i.e., Ramabadrapuram) and the demand for
the raw material can be fulfilled by the remaining
vendors, raw material should not be procured from
the vendor 4. Table III represents the production plan
for the optimal product mix. It gives us the quantities
of material to be produced by both the facilities
considering the demands of the customers and their
transportation cost.
Table II, IV and V represent the transportation plans
for the plant. Table II shows the quantities of material
to be transported from different vendors to both the
facilities. Table IV shows the quantities of different
goods to the shipped to the warehouses from both the
facilities. Table V shows the quantities of different
goods to be transported from different warehouse to
all the customer locations. The Transportation cost to
ware house 4 is very high from both the facilities and
it is also very far away from all the customer zones,
so the warehouse 4 is discarded from the plan. From
the above obtained plans the total cost of the supply
chain is calculated as Rs.27, 41,039/- per one time
period (i.e.12 hours). The obtained value is
Rs.2,02,539/- less than the existing cost.
V. CONCLUSIONS
In this paper supply chain network is
designed for a dairy industry. This network includes
material purchase plan, production plan, inventory
plan and transportation plan. From the results it is
observed that the total cost of the supply chain is 9.8
percent lesser than the existing cost. This model can be
extended to varying demand and costs. This can also
be applied to fast moving consumer goods.
REFERENCES
[1.] Supply-Chain Council, Inc., 1998, Overview
of the SCOR Model V2.0, www.supply-
chain.org.
[2.] Clark, A. J., and Scarf, H., 1960, Optimal
Policies for a MultiiEchelon Inventory
Problem, Management Science, Vol. 6,475-
490.
[3.] Cohen, M. A., and Huchzermeier, A., 1998,
Global Supply Chain Management: A survey
of Research and Applications, Quantitative
Models for Supply Chain Management,
Kulwer academic publishers .
[4.] Ehap H. Sabri and Benita M. Beamon 2000,
A Multi-Objective Approach to Simultaneous
Strategic and Operational Planning in Supply
Chain Design, Omega Vol. 28, NO.5, 581-
598.
[5.] Ganeshan, R , Stephens, P., Jack, E . , and
Magazine, M., 1999, A taxonomic review of
supply chain management research,
Quantitative models for supply chain
management. The Netherlands: Kluwer
academic publishers, 839 - 879.
[6.] Pyke , D.F . , and Cohen, M . A . , 1994,
Multi product integrated production
distribution system , European journal of
operations research. Vol 74 , No I , 18 - 49.
[7.] T. H. Lee and S.H . Kim. , 2000,optimal
production distribution planning in supply
chain management using a hybrid simulation
Analytic approach.
[8.] Thomas D. 1. and P. M. Griffin. , 1996, Co
coordinated supply chain management.
European journal of operation research, 94: 1-
15.
[9.] Arntzen, B. C., G. C. Brown, T. P. Harrison
and L. Troflan, 1995, Global supply chain
management at digital equipment corporation.
Interfaces: 25, 69-93.
Proceedings of the World Congress on Engineering 2009 Vol I
WCE 2009, July 1 - 3, 2009, London, U.K.
ISBN: 978-988-17012-5-1
WCE 2009