Geoscience Reference
In-Depth Information
Procurement
Links
Transportation
Lin
ks
Storage
Links
Transportation
Links
Processing
Links
Distribution
Links
C
1
S
1
,
1
S
1
,
2
A
1
B
1
R
1
1
.
.
.
.
.
.
.
.
.
.
.
.
Demand
Points
Organiza
ti
on
C
n
C
S
n
S
,
1
S
n
S
,
2
A
n
A
B
n
B
R
n
R
Fig. 15.1
Network topology of the integrated disaster relief supply chain
Regardless of the strategy that the relief/humanitarian organization will eventu-
ally adopt—the procurement of relief goods in advance or subsequent to the disaster
or a combination of both—the ultimate delivery of the items to each demand point
is aimed to be completed within a specific time target associated with that point as
closely as possible. Such goal constraints enhance the reliability of a disaster relief
system. All disaster relief organizations, whether owned and run by the public or
the private sector, are non-profit. Thus, a centralized system-optimization approach
is adopted as recommended by Nagurney et al. (
2011
).
Figure
15.1
depicts the network topology of a disaster relief supply chain
associated with a humanitarian organization responsible for the procurement and
the delivery of a disaster relief product. The progression of the required activities in
such systems over time is graphically depicted. Depending on the location and the
type of the relief product, be it water, food, medicines or vaccines, for example, the
disaster relief organization can represent the US National Guard, the American Red
Cross, the International Federation of Red Cross and Red Crescent Societies
(IFRC), Doctors without Borders (MSF), etc. The organization, in Fig.
15.1
,is
denoted by the origin node. Every other node in the supply chain network represents
a facility in the supply chain. A path connecting the origin node to a demand node
(destination) consists of a sequence of directed links with each one corresponding to
an activity in the supply chain. This sequence of activities ensures that the disaster
relief item is procured, positioned, stored, and distributed to the people in need. We
assume that there exists at least one path in the supply chain network connecting the
origin (node 1) with each demand point located at the rightmost (final) tier of the
supply chain (with additional assumptions stated later).
In the topology in Fig.
15.1
, we assume that the organization is considering
n
C
procurement facilities, denoted by
C
1
,
C
2
,
...
,
Cn
C
. These are the locations where
the purchased aid item is received from, or the item is collected from donors, such
as people, companies, etc. Associated with each type of procurement is an individ-
ual cost function. Collection nodes constitute the second tier of the supply chain,
and the links connecting the origin to these nodes correspond to the activities of
“procurement.”
