1. A method for implementing a business application comprising: in a computer system having a context repository in which at least two context templates are stored, each of the context templates representing a meta-model of a business situation, and an action repository in which at least two action definitions are stored, which action definitions define at least an input or output of a service, instantiating a context based on a context template stored in the context repository such that the instantiated context is a model of a business situation; associating at least one action definition with the instantiated context; and mapping at least one parameter of the instantiated context with at least one input or output parameter of the associated action definitions and using the mapped parameter as input data to the service or outputting data from the service to the parameter when the business application is running.