In this paper, we consider a way to represent contact center applications as a set of multiple XML documents written in different markups including VoiceXML and CCXML. Applications can comprise a dialog with IVR, call routing and agent scripting functionalities. We also consider ways how such applications can be executed in run-time contact center environment.

In this paper we apply a formal approach, based on Petri nets, to design a logical structure for call centers based on sophisticated computer telephony integration applications. A typical call center consists of a set of operators, called agents, who process inbound calls from clients. This call processing may involve the use of computer systems and other devices, such as faxes, as well as communication with other agents. The treatment of each call being processed is heavily regulated by a script, which is specially designed for specific kinds of calls by the experts in telemarketing. However, the design of such scripts can be problematic. In this paper, we stress the need for tools supporting a scripting process. We propose a formal model intended to serve as a basis for such tools. Specifically, we introduce formal models called script nets for formal representation of scripts and of the call center as a whole. We have also introduced various ways to structure script nets, using a transition hierarchy and macroplaces.