Middleware Services to support Electronic Commerce
by Dimitris Papadakis, Manolis Marazakis and Christos Nikolaou
The Parallel and Distributed Systems (PLEIADES) group of ICS-FORTH is pursuing research in the area of large scale distributed applications over the web. Electronic commerce is of particular interest, as a distributed process that entails activities such as searching and advertising, negotiating, contracting and ordering, billing and payment, distribution and receipt, and customer services. Not all these activi-ties are performed in every commerce transaction, nor are they necessarily performed in this order. Indeed, they may be performed in parallel.
Electronic commerce will benefit from an infrastructure that encapsulates these activities into autonomous agents and provides services for co-ordination and collaboration. Such an infrastructure may benefit other distributed applications, such as digital libraries, collaboration support environments, distributed performance monitors, as well.
The environment we are developing provides services to support electronic commerce activities and consists of the following components:
- Agent Environment
- Workflow Management
- Repository Service
- Monitoring Service.
Agents are software components with essential qualities; they are autonomous, persistent and mobile and they can reason, act and communicate. In our environment we use software agents to encapsulate electronic commerce activities.
Customers agents can learn an individual customer's preferences, maintain profiles, seek out appropriate merchants, and when necessary request further information from merchants. Agents can also negotiate prices, payment and delivery options, and either alert customers about potential bargains or initiate purchases. On the other hand, merchants' agents provide product, price, billing, and payment information to customers' agents. They may simply reply to requests for information or may actively seek out customers' agents. Finally, agents can deliver purchased products to customers, collect payment, and enforce intellectual properties rights.
Figure: Collecting product information with agents.
Interoperability is a key aspect in electronic commerce, since the Web is an open system with heterogeneous information sources. Many agent based environments face this issue with specialised agents for every resource. In our environment, we maintain a collection of access interfaces in a distributed repository that may be replicated to enhance availability. Customers' agents negotiate with merchants to decide the appropriate interfaces to load from the repository. This service enables a single agent to access a plethora of diverse resources, extending its default capabilities.
Workflow automation allows the implementation of complex models of interaction. The desired flow of information and control is described to the workflow management system with a specification language. At execution time the workflow manager sequences the commerce activities, passing data and control appropriately among agents. Removing assumptions about activity sequencing and data routing from agents improves their robustness to changes. Furthermore, alternatives to certain activities can be described in the specification language if agents fail to complete their task.
Maintaining context and state information about electronic commerce transactions is an important requirement. Monitoring the current state of interactions is essential to provide customers timely information about the progress of their transaction. Furthermore, the behavior of the transactions to be performed can be described using the workflow specification language, thus enabling our environment to handle customers' requirements when transactions fail to commit.
We are building a prototype of the environment presented. We have implemented the parser for the workflow specification language and a centralized repository service. Mobile agents have been implemented that can migrate to sites and access resources through a collection of interfaces that are maintained in our repository. An appropriate network loader has been also implemented to enable agents to load access interfaces from the network, if these are not available locally. Our future work includes the implementation of the workflow scheduler and the distribution of the repository service.
Christos Nikolaou - ICS - FORTH
Tel: +30 80 391676