The main aim of this paper is to present how to transform user requirements models into a software architecture for mobile applications. The technique (called "4SRS") is essentially based on the mapping of UML use case diagrams into UML object diagrams. UML sequence, activity, and state diagrams and other artifacts can also be considered within the transformation decisions. The applicability of this technique is illustrated by presenting some results from an e-government mobile application.

The development of mobile applications typically follow a service-oriented approach. A service is a software entity running on one or more machines and providing a particular type of function to a priori unknown clients. These services must communicate with each other, whose combination makes up a service-oriented architecture. The communication can involve either simple data passing or it could involve two or more services coordinating some activity. Some means of connecting services to each other is needed, so workflow is a critical part of making services effective. When those services react to changes on user context, application are context-aware.

For mobile applications, the definition of the underlying service-oriented software architecture must consider the services themselves as user requirements, as well as the mobile operators entry-points and the final clients interfaces, and use them to characterize the platform.