By M. Anwar Usman
B. Eng (Hons), UK; MSc (UK)
June 09 - 15, 2003




M. ANWAR USMAN is the Managing Director of Universal Board and Industries. He is an industrialist and an entrepreneur. Anwar completed his Bachelors in Electronic and Communication Engineering from the University of Liverpool, UK in 1997 and joined Perfect Engineering Works as Operations and Technical Support Manager. He has also worked for Siemens Pakistan Engineering and Philips Electrical Industries of Pakistan. After few years of work experience, he decided to get professional degree in computer sciences and did MSc in Business Information Technology from another prestigious University of Manchester Institute of Science and Technology (UMIST), UK in 2001. Later, he joined Metropolitan Bank as a Systems Analyst and Systems Designer. And also started Lecturing, Software Engineering Projects Consulting and writing/supervising research papers for MS/PhD level program at SZABIST. Also actively participating in activities carried out by Association for Computing Machinery (ACM) Karachi chapter and IEEE Karachi chapter. He is a professionally designated MIEE and MIEEE. Also member of ACM, Member of Pakistan Engineering Council (PEC) and Member of Committee for Telecommunication and Software Development at the Federation of Pakistan Chambers of Commerce and Industry (FPCCI) as well.

The aim of the article is to investigate a certain approach to flexibility in enterprise information systems architectures in e-business. The investigation deals with two aspects: first, the problem context, and then, the approaches and technologies that have been surveyed.

We discuss the trend of enterprise moving towards e-business and the requirement for flexible and scalable system architectures in this respect. Following this we discuss the generic software architectures, assess ways of achieving flexible business-to-business data interchange. In this article, we examine a few of the potential roles E-Marketplaces can play, and demonstrate their computational feasibility and their usefulness. Then we present architecture of a distributed E-Marketplace for trading soft and physical goods and services, and describe the economic model assumptions for the operation of the marketplace. Next we give a brief overview of the online auction as a negotiation mechanism, and then we presents some actual online marketspaces for case studies. As we conclude the article by presenting various approaches to brokerage.




In many cases, electronic commerce is confused with EDI, which is a set of data formats, and protocols for conducting highly structured inter-organization exchanges, such as making purchases or initiating loan requests. EDI has been traditionally limited to codified transactions defined in advance, while electronic commerce, as a whole, is more flexible with EDI representing only a subset of electronic commerce. Unfortunately, despite the widespread use of numerous methods of electronic support, electronic commerce is still not the most common method of carrying out business transactions. This is so for several reasons. For one thing, most business transactions still require the physical exchange of paper documents and instruments, with the inherent costs and delays this represents. For another, current electronic commerce approaches are not sufficiently well integrated, secure, open, or easy to use. Several technical and business-related problems are hampering the widespread use of electronic commerce.


The need for flexible, platform-neutral and scalable architecture is demand of companies that needs to adapt itself to an e-commerce set-up. Information Technology (IT) has made lot of development in providing these solutions for business to achieve the level of co-ordination without facing many challenges nowadays. And to investigate to provide such as flexible architecture for companies will be a milestone in research field. The reasons for this mentioned in the following headings are detailed in the following sub-sections. Investigation of scalable and flexible architecture for e-businesses is relevant to businesses engaging in profitable e-business arrangements with their trading partners.


Client Server systems have become a popular architecture for e-business all over the world because of their scalability. In many industries, adopting leading-edge technologies such as 3-tiered client/server is a competitive necessity.


The three-tier architecture (also referred to as the multi-tier architecture) emerged to overcome the limitations of the two tier-architecture.

There are a variety of ways of implementing this middle tier, such as transaction processing monitors, message servers, or application servers. The middle tier can perform queuing, application execution, and database staging. In addition the middle layer adds scheduling and prioritization for work in progress.




Though 2-tier client/server architectures are still dominant in distributed computing environments, there is a steady migration towards 3-tier configurations. In 3-tier client server architectures, functions are separated into presentation, business application and data components. The 3-tier architecture provides potentially more adaptive architecture than the 2-tier architecture; it is designed with the flexibility level to support both changes in the business environment and changes in technology. On the downside, it should be noted that downloading applications from the server would take some bandwidth from the network.


Along with many single-company sites, the Internet contains an increasing number of portals that deliver what are known as Web services, which use the existing infrastructure to deliver data. For example, Request For Quotes (RFQs) enable businesses to solicit the best prices for items they want to buy using a reverse auction process. To continue offering these profitable new services, enterprises need a standard, cost-effective way to exchange data and information over the network.


Regardless of the specific middleware technology used, middleware offers a great advantage of platform-independent interoperability by hiding completely the distributed aspect of a client/server-based network and therefore one doesn't need to indulge network programming. However, the practical difficulty that some have experienced with middleware is that it works better where the organization is in control of the interfaces. Thus, in the context of inter-enterprise integration, this approach does not appear practical.


Data centric solution would allow companies to share more common ground in terms of the documents they exchange, as opposed to business system interfaces. i.e. (better level of exchanging documents than programmed interfaces for the enterprise). Therefore, there is good reason on the basis of above arguments to use data centric solutions to focus on exchange formats. In following sections contemporary approaches to data centric solution are discussed. Those are EDI technology and recently a new technology XML, which is gaining very quickly acceptance for many portable data solutions.


EDI aims to enhance, facilitate and enable the transmission of business documents between the information systems in Business-to-Business (B2B) e-commerce. They transform the data to be exchanged from the format used in the local information system to one of the several EDI standard formats (e.g. ANSI X12 and UN/EDIFACT) which involves the use of specialized translator programs. The benefits of such data interchange are in line with the motivation to reduce coordination costs and improve quality and accuracy of record keeping. This results in faster and more precise decision-making. Despite its undeniable advantages, the standard's acceptance in the industrial world is on the whole restricted to large corporations. There are two main reasons for this: firstly, the financial hurdles presented by the installation of an EDI solution are extremely high and additional to the volume-based operating costs that are incurred for actually transferring data. Secondly, all the companies concerned have to agree on which standards should be used.




Ideally, a self-describing XML document would include all the content and context that two dissimilar applications, the sender and receiver, need for full interoperability. Applications would be able to exchange documents whose intended processing by the recipient is self-explanatory. XML in just few years has become a universal standard for distributed computing. It is rapidly occupying most application niches in the N-tier architecture or Intranets, Extranet, and the Internet. And it fits into N-tier/three tier architecture environment.

The standard APIs and separation of content from eventual presentation or use also means XML can have multipurpose applications as it allows mark-up of any nature of data. Hence, current uses include Java application server configuration, business rules representation, dynamic web-page support, and DBMS storage format. Applying stylesheet (XSL) to the XML document, the client can display the information in HTML or other formats. By using the SAX or DOM APIs, application developers don't need to worry about the implementation environment. In the business logic tier, XML provides a universal format for data interchange, aggregation, search and manipulation. XML also represents a universal format for encoding, interchange, and reuse of business logic at the application server level. The business logic tier is where XML will play its primary role in distributed environment. Typically, an XML enabled application server translates data from legacy databases into XML format and integrates diverse data objects into a logically unified view. In the data tier, XML provides an application-neutral data storage and interchange format for any highly structured information. In the near future, many may also support XML as a native data storage format.

Examples of this include the Microsoft Simple Object Access Protocol (SOAP) which uses XML for data exchange along with current efforts of OMG to incorporate XML into its Common Object Request Broker Architecture (CORBA). SAX parser offers a "persistent management of text trees". Where as CORBA risks deserialisation errors if class definitions are changed. And when look at the Java-based RMI class versioning, it's not that flexible as DTD versioning for XML.

And of course, as XML is human-oriented, it allows relatively less complex manual intervention if required. Nevertheless, it has to be argued that in the domain of business document exchange, XML is the better choice due to the human readability and extensibility. And for this reason many companies are changing their plans for replacing their systems with XML based architecture instead of using CORBA.


In order to participate in e-commerce collaborations and remain competitive an enterprise needs a flexible business process, which can adapt to changes that occur in the market, regulatory bodies, laws, or internal goals changes. To rapidly enact the changes mentioned above, an enterprise needs to understand its way of doing business. This includes understanding the enterprise's business rules, which are statements that reflect policies, procedures, or other constraints on ways to satisfy the customers, make good use of resources, or conform to laws or industry regulations.

Trigger rules are defined early in the database design and are revised infrequently. An example of a business rule in the same retail system would be "Preferred customers receive a 10% discount". However, many special circumstances exist when calculating an appropriate discount. Another business rule that may be applicable is "Orders greater than 500 units receive a 30% discount". These rules can become very complex and difficult to enforce. Also, one of the main characteristics of business rules is their frequent change, according to the enterprise's need to adapt to market changes, laws or changing enterprise goals. This property further complicates the process of enforcing the business rules. There is little work in the literature regarding the specification, enforcement and distribution of business rules in distributed environments.

Vendor neutral standards bodies and industry consortiums have developed e-commerce components that can be used for a rapid and uniform construction of e commerce applications. One such example is the Common Business Language (CBL) [CBL], which comprises XML documents for the exchange of purchase orders, invoices, catalogue content, etc. However, CBL doesn't allow for the explicit manipulation of business rules.



(To be continued)