With the rapidly changing forecasting techniques, this paper introduces a flexible application framework to develop different forecasting systems. When a user develops a system based on this framework, he can add new forecasting techniques easily. We first analyze the forecasting process and develop an abstract common process for building forecasting models. This abstract common process is then used to develop the application framework. Web Services Business Process Execution Language (WS-BPEL) is used to describe the model building process. This framework can integrate methods and data from different forecasting technologies by defining method and data configuration.