Assessing Dependability for Mobile and Ubiquitous Systems: Is There a Role for Software Architectures?

A traditional research direction in Software Architecture (SA) and dependability is to deduce system dependability properties from the knowledge of the system SA. This well reflects the fact that traditional systems are built by using the closed world assumption. In mobile and ubiquitous systems this line of reasoning becomes too restrictive to apply due to the inherent dynamicity and heterogeneity of the systems under consideration. Indeed, these systems need to relax the closed world assumption and to consider an open world where the system context is not fixed. In other words, the assumption that the system SA is known and \fxed at an early stage of the system development might be a limitation. On the contrary, the ubiquitous scenario promotes the view that systems are built by dynamically assembling available components. System dependability can then at most be assessed in terms of components' assumptions on the system context. This requires the SA to be dynamically induced by taking into consideration the specified dependability and the context conditions. This paper will illustrate this challenge and, by means of an illustrative scenario, will discuss a possible research direction.