A voice application creation and deployment system includes a voice application server for creating and serving voice applications to clients over a communication network; at least one voice portal node having access to the communication network, the portal node for facilitating client interaction with the voice applications; and an inference engine executable from the application server. In a preferred embodiment the inference engine is called during one or more predetermined points of an ongoing voice interaction to decide whether an inference of client need can be made based on analysis of existing data related to the interaction during a pre-determined point in an active call flow of the served voice application, and if an inference is warranted, determines which inference dialog will be executed and inserted into the call flow.