Safety shell for specification-PEARL oriented UML real-time projects

A safety shell for real-time applications to be developed with UML is defined based on a re-configuration management pattern. Inspired by the architectural specifications in the Specification PEARL methodology, the pattern is parameterised by defining the properties of its components as well as by defining how the software is to be mapped to the hardware architecture. The initial and alternative scenarios are defined as well as the method for switching between them. This article includes the description of the UML pattern and of its parameterisation method, with the goal to obtain clearly specified operation scenarios with well-defined transitions among them. In order to achieve safe and timely operation, the pattern must provide a safety shell for all scenarios, i.e., enable their deterministic, temporally predictable operation, and transitions between them.