A modelling system to provide a computer based business process for an enterprise, allows the enterprise to input values for a plurality of non functional requirements (760) for the deployment, and allows at least some of the values to be varied independently of others of the values, and creates a design of software application components (770) and a design of computing infrastructure (780), for running the software application components, so that the business process operates according to the values input for the non functional requirements of the business process. By modelling the underlying computing infrastructure, it becomes feasible to create models with greater certainty that they will deploy successfully, and with greater predictability of how well they will meet given non functional requirements. This enables more freedom to be allowed to vary the values of these non functional requirements and get greater customisation to suit the needs of the enterprise.