Abstract
Purpose The purpose of this paper is to propose a fourlevel hierarchy model for multimedia documents representation to be used during the dynamic scheduling and altering of multimedia contents. Designmethodologyapproach The fourlevel hierarchy model object, operation, timing, and precedence, offers a finegrain representation of multimedia contents and is embedded within a research tool, which is called WEBCAP. WEBCAP utilizes the fourlevel hierarchy to synchronize the retrieval of objects in the multimedia document employing Allen's temporal relations, and then applies the BellmanFord's algorithm on the precedence graph to schedule all operations fetch, transmit, process, and render, while satisfying the intime updating and all web workload's resources constraints. Findings The experimental results demonstrate the effectiveness of the model in scheduling the periodical updating multimedia documents while considering a variety of workloads on webTCP. Research limitationsimplications WEBCAP should be enhanced to automatically measure andor approximate the available bandwidth of the system using sophisticated measurement of endtoend connectivity. In addition, WEBCAP should be expanded and enhanced to examine system infrastructure for more realtime applications, such as telemedicine and elearning. Practical implications WEBCAP can be used as an XML markup language for describing multimedia presentations. It can be used to create online presentations similar to PowerPoint on desktop environment, or used as an interactive elearning tool. An HTML browser may use a WEBCAP plugin to display a WEBCAP document embedded in an HTMLXML page. Originalityvalue This paper proposed a dynamic scheduling of multimedia documents with frequent updates taking into consideration the network's workload to reduce the packet lost ratio in the TCP flow, especially in the early stages. WEBCAP can be used to guide distributed systems designersmanagers to schedule or tune their resources for optimal or near optimal performance, subject to minimizing the cost of document retrieval while satisfying the in time constraints.