Process systems engineering (PSE) provides means to solve a wide range of problems in a systematic and efficient manner. This presentation will give a perspective on model based methods and tools needed to solve a wide range of problems in product-process synthesis-design. These methods and tools need to be integrated with work-flows and data-flows for specific product-process synthesis-design problems within a computer-aided framework. The framework therefore should be able to manage knowledge-data, models and the associated methods and tools needed by specific synthesis-design work-flows and data-flows. In particular, the framework needs to manage models of different types, forms and complexity, together with their associated parameters. The application range of the framework depends very much on the application range of the associated models. Therefore, a modelling tool-box is also a part of the framework. The issue of commercial simulators or software providing the necessary features for product-process synthesis-design as opposed to their development by the academic PSE community will also be discussed. An example of a successful collaboration between academia-industry for the development of model based methods and tools within a computer aided framework for product-process synthesis-design will be highlighted.