A GRID SERVICE COMPUTING ENVIRONMENT FOR SUPPLY
CHAIN MANAGEMENT
Sam Chung and George A. Orriss
Computing & Software Systems, Institute of Technology, Univ. of WA Tacoma,
Box 358426 1900 Commerce St., Tacoma, WA 98402, USA
Keywords: Grid Services, Web Services, Service-Oriented Computing, Supply Chain Management, Business to
Business (B2B) application integration.
Abstract: This paper proposes to develop a Grid Service Computing Environment for Supply Chain Management.
Current research into Grid Services for distributed systems has resulted in interesting questions being raised
as to whether or not the Open Grid Service Architecture can be applied to developing a Supply Chain
Management system. If so, how will it affect development of SCM systems as a typical example of
Business-to-Business (B2B) application integration? Since as much recent development has been focused
on resource allocation in a Grid environment, the B2B application integration using Grid computing is still
relatively unexplored. By developing a Supply Chain Management system using the Open Grid Service
Architecture and the Globus toolkit, this research will provide an infrastructure for composing existing
services into a system that can be utilized for Supply Chain Management. The result of this project is a Grid
environment that provides efficient and effective service management of available Supply Chain
Management services. Also, we address some of the inherent issues of dynamic binding and automation
associated with B2B transactions, such as those surrounding security protocols, service lifecycle, and
instance creation.
1 INTRODUCTION
This paper develops a Grid service-computing
environment (Fox, 2003) for Supply Chain
Management (SCM), which relates to any service
that concerns delivery of goods, services, and
information from the supplier to the customer.
There are two primary motivations behind this:
• Show the benefits of applying Grid service
computing to SCM applications in an efficient
and effective manner.
• Illustrate the abilities of the Open Grid Service
Architecture (OGSA), which is a well-defined set
of basic interfaces concerning the discovery and
invocation of Grid and Web services, to allow for
dynamic creation of customized services using
separate and distinct Web services.
Initially, Grid computing is distinctly related to
building supercomputing environments through the
sharing of computing resources (Blythe, 2002).
There are problems inherent to designing a system
of this nature. The main question: Can an OGSA be
applied to develop a SCM system? Considerable
research has been conducted regarding the OGSA in
order to illustrate the applicability of using it to
incorporate Web services from various sources into
a specific, customizable service environment
(Foster, 2001 and 2002). Through this approach, this
project shows the benefits and advantages of
utilizing the OGSA to compose a SCM system.
First and foremost, the nature of Grid computing has
traditionally lent itself to the area of resource
allocation for computing operations, specifically
along the lines of scientific research. In addition, as
Grid computing evolution has largely occurred in the
last five years, much work related to employing Grid
architecture to Web service binding is theoretical in
nature, with little actual implementation to use as
reference.
Building on this issue then, the second question
arises: If such a system can be built, how will it
affect the development of SCM systems as a typical
example of Business-to-Business (B2B) application
integration? Of primary concern with any B2B
application, inherent issues have always existed
relating to various security protocols, service
112
Chung S. and A. Orriss G. (2006).
A GRID SERVICE COMPUTING ENVIRONMENT FOR SUPPLY CHAIN MANAGEMENT.
In Proceedings of the Eighth International Conference on Enterprise Information Systems - SAIC, pages 112-117
DOI: 10.5220/0002466001120117
Copyright
c
SciTePress
lifecycle management, and transaction instance
creations regarding a particular system. For each
system/service a client wishes to access for SCM
systems, they must address these issues relating to
binding to that particular service. What the OGSA
brings to developing such systems is a single, stable
environment that allows the client to be concerned
with one service instance creation that handles
service binding and all related B2B transactions via
the use of one security certificate.
To achieve the desired results, implementation of
the Globus toolkit, which is based on the OGSA
protocols, is utilized in conjunction with an example
of SCM. Globus has been designed as an all-in-one
application for establishing a Grid computing
environment while following protocols defined by
the Global Grid Forum (GGF) relating to numerous
trust and security issues (Foster, 2002, Alonso,
2004). The toolkit employs a standard set of
interfaces that automate location and binding to
services, among other functions. Additionally, these
interfaces allow for platform and language
independence via their design, thus allowing the
incorporation of services previously isolated due to
these constraints.
As Information Technology (IT) industry trends
regarding cross-enterprise B2B collaboration lend
itself to the concept of “virtual organizations”
(Foster, 2001, Alonso, 2004), it seems logical to
utilize Grid computing to attain these goals.
Therefore, the system employs two major
components: the Open Grid Service Infrastructure
(OGSI) that provides a grid environment via use of
the Globus toolkit, and designed/developed SCM
service(s) in order to provide the virtualization
(composition), which is necessary to allow access to
resources across multiple heterogeneous platforms.
Through illustrating the possibilities of the resulting
environment, a new infrastructure for B2B
interactions is realized that allows for
interoperability of services without concern for
language or platform dependence, as well as
inherent issues of trust and security.
2 SCM AND WEB SERVICES
There have been previous implementations of the
OGSA that have focused on resource the area of
resource allocation for scientific computing
operations. Most have been tied to resource
management and allocation (Fox, 2003).
Developing a system for SCM using the OGSA has
not yet been done, so work relating to similar
systems of this type must be referenced for design
and implementation examples. It is possible to run
test implementations utilizing the OGSA in
conjunction with an existing Weather Grid Service
(Schneider, 2003) as an example of the possibilities
available by this technology. This service utilizes an
existing service that provides current weather
conditions (temperature) based on a user-supplied
zip code, and while is a good starting point, doesn’t
provide an example of a Grid service composed of
more than one Web service.
Regarding the approach of using the OGSA in
distributed system B2B integration, e-services have
been designed based on the configuration of custom
Grid services defined using WSDL port types
(Foster, 2002). This is the type of approach that will
be applied in developing this system, as this has
been shown to be a reasonable and flexible
implementation. Each service composition must
address issues of trust and security among possible
unrelated services that are interacting, so the Globus
toolkit handles standard semantics for interactions
such as these.
Important to understanding and implementing
this new type of service composition will be the
handling of services located and binding to them in
order to compose the Grid service desired. Research
into “portlet” (Gannon, 2003) design provides
insight into a graphic interface that shows available
services in a tabbed environment, which can then be
used as the composition base. As this is more theory
than functionality-based, problems that occur when
incorporating the interface aspect of the Grid
environment needed addressing.
3 APPROACH
In order to develop a Grid service computing
environment for SCM, there are two primary
components that were needed for the project: the
Open Grid Service Infrastructure (OGSI) for the
SCM using OGSA and the SCM example. The SCM
example was designed for performance related to
purchasing order placement, fulfilment and other
possible B2B transactions: retailer, suppler, and
manufacture grid services. (Due to the space limit,
the retailer grid services are explained in detail
here.)
A GRID SERVICE COMPUTING ENVIRONMENT FOR SUPPLY CHAIN MANAGEMENT
113
3.1 OGSI for SCM
The OGSI for SCM is shown in Figure 1. The Grid
Service Server (GSS) is the hosting environment (in
this case, a Linux Fedora Core version 2 operating
system is used.) There are three independent Web
services shown in the deployment here, each
providing services for one of the three actors such as
a retailer, supplier, or manufacturer that would use
the SCM system. Through manual discovery and
composition by the Grid Service Administrator
(GSA), necessary codes are supplied that handles the
binding, composition, and deployment of these
services into the GSS. Once this is completed, any
Grid Service Client (GSC) can access services that
they have permission to access. The GSA can
provide any number of CA (Certificate of
Authority)’s, depending on what types of services
are to be provided to the clients utilizing that
particular certificate. By utilizing this infrastructure,
a client is concerned with one instance of service
discovery, security and binding protocols, whereas a
non-Grid approach would involve dealing with Web
service’s individual protocols in order to connect to
each service. The OGSI provides a standardized
security and management system that is controlled
by the GSA, and allows ease of use for any number
of clients.
3.2 Retailer Grid Service
For the implementation of this project, the Supply
Chain Management system is designed with a
Retailer being the first in the chain of execution.
The Retailer in this example would be any of a
number of stores wishing to order more inventory of
soda for their locations. In order to do so, access to
an available supplier’s inventory is essential.
Implemented Solution: For purposes of the Grid
service for retailer functionality, a fairly
straightforward approach was taken, developing a
Java-based Web service that could then be deployed
in the Globus environment. The example used was
that of a retailer (client) wishing to update inventory
through ordering from a main supplier (warehouse).
In order to achieve this, the application was designed
with classes utilizing different operations relating to
SCM functions.
Grid Service
Client Retailer
(GSCR)
Grid Service
Server (GSS)
Web Service
Retailer (W SR)
Web Service
Suppplier (WSS)
Web Service
Manufacturer
(WSM)
Web Service
Directory (WSD)
Grid Service Security, Discovery, Binding (GSS, GSD, GSB)
Grid Service
Client Supplier
(GSCS)
GSS, GSD, GSB
Web Service Discovery
Web Service Binding (WSB)
WSB
WSB
Web Service Publishing (WSP)
WSP
WSP
MySQL DatabaseMySQL Database
MySQL Database
Grid Service
Client
Manufacturer
(GSCM )
GSS, GSD, GSB
Figure 1: Overview of the Open Grid Service Infrastructure for Supply Chain Management.
ICEIS 2006 - SOFTWARE AGENTS AND INTERNET COMPUTING
114
Primarily, a user interface was the main focus
here, providing a user-friendly environment for
selecting different items to order, and prompting the
user for the desired quantity. In order to assist in
this process, the service populates a list of current
inventory from the warehouse, so that the retailer
can ascertain what is available. Each item is then
added to a pending order along with the input
quantity desired. Once the retailer confirms the
order, the final order is displayed in a corresponding
pane, a purchase order generated, and a
corresponding database insertion of the purchase
order occurs.
Once the transaction has been completed and the
purchase order stored, it can then be accessed by the
warehouse (supplier) for purposes of
confirming/shipping the order. Using two essential
files for deployment, ‘deploy-server.wsdd’ and
‘build.xml,’ the designed Web service is converted
and launched as a Grid service in the Globus
environment. Discussion of the important elements
code in these files is covered here, but applies to any
deployed Grid service.
Grid Service Methods: The Retailer Grid
service consists of several methods, due to the
variety of operations performed by the service. The
main classes that comprise the service: The main
classes are the RetailerGUI and DatabaseConnector
with other classes playing important parts in the
service functionality as well. Regarding the
RetailerGUI class, the obvious primary functionality
concerns the user interface, but it is important to
note a very specific method that relates solely to
Grid service functionality, and is unique from
standard Java Web services. The
getRetailerServiceInterface is a unique method that
is designed to create and instance of the
RetailerPortType necessary for communication with
the Grid service running in a host container. For
each client accessing a particular Grid service, a
unique port is opened, and this connection is
managed by Globus for all aspects of security,
lifecycle, data transfer, etc.
The DatabaseConnector class features key
methods to handle the connection to a remote
database, in this example the MySQL system. Most
of the remaining operations in this class relate to
database information storage and retrieval, as
methods such as selectAllInventory, insertPO,
updateDB, and others perform. This is the class
where much revision can be performed when it is
desired to add additional functionality to the Retailer
Grid service.
Also it should be mentioned that the Retailer
interface and the RetailerImpl classes are key
elements to the Grid service, as they provide
essential functionality for utilizing the
RetailerPortType.
4 RESULTS
The following sections discuss the results and
lessons learned from the development of a supply
chain management system using Grid service
computing environment. The first two sections
discuss the results obtained when deploying the Grid
Service Computing Environment and the Grid
services deployed in that environment, in order to
answer the question as to whether or not an Open
Grid Service Architecture can be applied to
developing a Supply Chain Management system.
The last section compares and contrasts Web and
Grid Service Oriented Architectures in order to
ascertain the feasibility of development of SCM
systems as a typical example of Business-to-
Business application integration.
4.1 Grid Services for SCM
Although the three components of this SCM system
such as a retailer, a supplier, and a manufacturer
performed different functionality, the design and
implementation of all of them were very similar with
regards to both positive and negative experiences.
Because extensive works were done during the
course of this research project attempting to use
existing SCM systems, the actual design of Web
services for composition into a Grid service proved
to be more easily attained. By working with
different code examples, it was possible to better
understand Web services themselves and in doing
so, understand how the Grid service concept is very
similar to Web services, but allows one to deploy a
variety of services that can be managed with one set
of standards, as opposed to many. For clarity, Table
1 shows a comparison of the original Web service
components and their corresponding components
after deployment as Grid services.
Each of the above service components was
originally designed as a Java-based Web service
accessible through one or more user interfaces. By
applying the OGSA to deploy the separate
components as Grid services, they are transitioned
into the corresponding Grid service. These are
known as factory services in the OGSA, and as each
A GRID SERVICE COMPUTING ENVIRONMENT FOR SUPPLY CHAIN MANAGEMENT
115
is deployed, the Globus toolkit allows any number of
clients to connect to one or more services provided
they have the correct CA installed on their machine.
What was clearly obvious through the work done
with this deployed system was that it was possible to
create numerous instances of the deployed Grid
services and perform the designed functions without
any problems due to security, speed, or reliability.
The built-in management tools that are part of
Globus allowed these tests to be successfully
executed. The aspects of service management
concerning security, instance creation, lifecycle, and
the like were performed as “behind the scenes”. As
each service could run independently of the others
and in numerous instances, it greatly illustrated the
desirability of this type of environment for hosting
and providing services to any number of clients with
specific needs.
Table 1: SCM service comparison.
Web Service Grid
Services
Retailer Retailer Web
Service/ RetailerGUI
Retailer
FactoryService
Supplier
(Warehouse)
Supplier Web
Service/
SupplierGUI,
SupplierShipGUI
Supplier
FactoryService
Manufacturer Manufacturer Web
Service/
ManufacturerGUI
Manufacturer
FactoryService
On the downside, the limitations mentioned
earlier regarding the toolkit led to a good deal of
time lost trying to get existing examples to work
with the Globus toolkit that in theory should be
possible. Although it could be cited as a shortcoming
of the Globus toolkit, it is actually further illustration
of the need for some type of centralized or common
ground for providing these types of services with a
minimal amount of overhead for the client.
4.2 WSOA vs. GSOA
Primarily, Web Service Oriented Architecture
(WSOA) and Grid Service Oriented Architecture
(GSOA) are the same conceptually, but the results
show the GSOA to be better in terms of stability,
reliability, and flexibility for incorporating different
components.
As Table 2 shows, the GSOA, although lacking a
defined registry for service location, offers many
other features that current WSOA standards do not
offer. To explain further, it is important to discuss
some of the aspects in Table 2.
Client Connectivity: Client connectivity in a
WSOA requires a client to deal with various
connection protocols depending on how each
separate service was composed. In contrast, the
GSOA requires one standard protocol for
connection. This is in concert with the Security
feature, which requires a Certificate of Authority
that allows the client to access all of the services of a
particular Grid server. Any client wishing access
simply needs to have the certificate installed relating
to the set of services to which access is desired.
Table 2: WSOA vs. GSOA.
Feature WSOA GSOA
Client
Connectivity
Multiple
Protocols
Single Protocol
Instance
Management
Separate and
inconsistent
Single,
consistent
management
Security Multiple
Protocols
One Certificate
(CA)
Binding to
services
Various,
confusing for
user
Handled by
GSA
Service design
and deployment
Platform,
language
dependent
Platform,
language
independent
Service
location
UDDI Registry No current
registry
Service
composition
Not possible
with differently
built services
Any number of
combinations
Instance Management: Each Web service must
be specifically designed to handle its own
management of instance creation, and many
protocols don’t address this effectively (Staab,
2003). This results in slower service response and
possible unavailability. The Globus Toolkit uses
default instance creation and management
parameters that can be changed by the Grid Service
Administrator to handle and allow multiple instances
of a service to run at once, and killing off service
instances if they remain inactive for the established
period of time.
Binding to services: For each Web service a
client wishes to connect to, there are issues of
location, handshake protocol, and the requisite
binding protocols that differ, depending on service
language, platform, etc. In the Grid service
environment, the Grid Service Administrator (GSA)
handles these issues who is a “middleman” for
service composition and provision.
ICEIS 2006 - SOFTWARE AGENTS AND INTERNET COMPUTING
116
Service design and deployment: Web services
are designed using a certain development tool,
language and platform, usually restricting client
access to similar environments. The GSOA is a
language and platform independent concept that
allows composition of services from different
environments, although the current reality of this is
more tightly coupled with the most recent version of
Globus.
There are additional features as well, but these
are some of the most pertinent and worthy of
analysis. For further clarification, note Figure 10
showing a theoretical client interaction with
different, existing Web services vs. that of a client
accessing different Web services via a Grid
computing environment: A client wishing to connect
to different Web services, after locating them via a
Web Service Directory (UDDI, for example), must
then connect to each service separately. In contrast,
a series of separate Web services deployed in a Grid
environment can be accessed by that client through
one connection with the Grid Service Hosting
Server. Clearly, the Grid Service Oriented
Architecture provides a more flexible, less-complex
client experience.
By illustrating how much more stable and
preferable the GSOA is for client connectivity,
access, security, and other related B2B transactions,
it is proven that the architecture used in this project
shows the future and viability of this type of SCM
system development as a typical example of
Business-to-Business application integration.
5 CONCLUSION
As evidenced by the results discussed above, the two
key questions put forth have been successfully
answered. Firstly, an OGSA can be applied to
developing a SCM system as illustrated by the
example implementation previously discussed.
Although systems of this nature have been
implemented before in a non-Grid environment, this
project shows a concrete example of a previously
theoretical implementation in a real world
application. The resulting system, through
implementation and testing, further goes to argue the
idea that this represents the future of Web services,
and a more stable environment for B2B application
integration.
Secondly, the viability has been shown
regarding the OGSA as the future in developing a
typical example of B2B application integration. The
detailed examples of the differences between the
WSOA and GSOA concepts, coupled with the
benefits of the singular administrative environment
of the OGSA has shown this to be a more stable,
desirable environment for B2B system development,
integration and deployment. In addition, as future
systems are designed with this architecture, their use
will become more commonplace.
The result of this project show OGSA and SCM
as a viable, working example as to the future of
SOC, but is intended as an initial foray into the
studied concepts upon which to conduct further
research and experimentation. Continued work
building upon the complexity of this system in
concert with advances in OGSA, Web service
framework standards, and more widespread use of
their concepts will greatly enhance the advancement
of the principles put forth by this research.
REFERENCES
Alonso, G. Casati, G. F., Kuno, H., and Machiraju, V.
Web Services: Concepts, Architectures and
Applications, Springer Verlag, 2004, pp. 315-319.
Blythe, J., Deelman, E., Gil, Y., Kesselman, C., Agarwal,
A., Mehta, G., and Vahi, K. The Role of Planning in
Grid Computing, American Association for Artificial
Intelligence, 2002, pp. 1-10.
Foster, I., Kesselman, C., Nick, J. M., and Tuecke, S. Grid
Services for Distributed System Integration, Computer
Magazine, June 2002, pp. 37-46.
Foster, I., Kesselman, C., and Tuecke, S. The Anatomy of
the Grid: Enabling Scalable Virtual Organizations,
International Journal of High Performance Computing
Applications, vol. 15, no. 3, 2001, pp. 200-222.
Foster, I., Kesselman, C., Nick, J. M., and Tuecke, S. The
Physiology of the Grid: An Open Grid Services
Architecture for Distributed Systems Integration,
Globus Research Website, June 2002, pp. 1-31.
Fox, G. Grid Computing Environments, Computing in
Science & Engineering, Volume: 5, Issue: 2, March-
April 2003, pp. 68 –72.
Gannon, D., Fox, G., Pierce, M., Plale, B., von Laszewski,
G., Severance, C., Hardin, J., Alameda, J., Thomas, M,
and Boisseau, J. Portal Architecture: A Portlet
Approach to Grid Services, Global Grid Forum, 2003,
pp. 2-15.
Schneider, M. Grid Support Tool Install for Windows
2000 Platform. June 2003.
Staab, S., van der Aalst, W., Benjamins, V. R., Sheth, A.,
Miller, J. A., Bussler, C., Maedche, A., Fensel, D., and
Gannon, D. Web Services: Been There, Done That?
Intelligent Systems, IEEE, vol. 18, no. 1, 2003, pp. 72-
85.
A GRID SERVICE COMPUTING ENVIRONMENT FOR SUPPLY CHAIN MANAGEMENT
117
