In this paper, we present data management issues faced during the design and development
of an open distance learning system for the University of Patras, Greece. In order to handle
data eciently, as required in a web tele-training application, for each type of information
maintained, dierent strategies must be deployed according to their behaviour and structure.
The diversity and complexity of data, the network aspect of the application and web de®-
ciencies impose an architecture design incorporating a plethora of technologies and tools that
must be integrated in such a fashion that they eciently organise these data preserving their
relationships. This presents a software engineering challenge requiring coherence of solutions
at all levels: structures, consistency, security, models, and protocols. The paper presents the
data components of an open and distance learning (ODL) system that access the information
stored in a database and the ®le system, their underlying technology, their interaction with the
network services, and features regarding the ways they address issues faced in an open vendorindependent
distance learning environment and outlines the system's overall architecture. In
addition, this paper presents the architecture, the design and the services of a network-based
information system that supports open and distance learning activities. The open and distance
learning information system (ODLIS) oers synchronous and asynchronous distance learning
and management of information system (MIS) services to support the educational procedure.
The ODLIS is a web-based application, which runs over the Internet using real time protocols.