Abstract—Designers of self-adaptive systems often formulate adaptive design decisions, making unrealistic or myopic assumptions about the system’s requirements and environment. The decisions taken during this formulation are crucial for satisfying requirements. In environments which are characterized by uncertainty and dynamism, deviation from these assumptions is the norm and may trigger “surprises”. Our method allows designers to make explicit links between the possible emergence of surprises, risks and design trade-offs. The method can be used to explore the design decisions for self-adaptive systems and choose among decisions that better fulfil (or rather partially fulfil) non-functional requirements and address their trade-offs. The analysis can also provide designers with valuable input for refining the adaptation decisions to balance, for example, resilience (i.e. satisfiability of non-functional requirements and their trade-offs) and stability (i.e. minimizing the frequency of adaptation). The objective is to provide designers of self-adaptive systems with a basis for multi-dimensional what-if analysis to revise and improve the understanding of the environment and its effect on non-functional requirements and thereafter decision-making. We have applied the method to a wireless sensor network for flood prediction. The application shows that the method gives rise to questions that were not explicitly asked before at design-time and assists designers in the process of risk-aware, what-if and trade-off analysis. I.

This paper revisits the relationship between software architecture and requirements focusing on the case of selfadaptive systems. The authors present their view of the state-of-the-art, including their own work, on both areas and their contribution towards the development of selfadaptive systems. The authors support the claim that there is no fundamental distinction between architectural decisions and architecturally significant requirements and discuss how these claims are specifically appropriate for the case of selfadaptive systems. A discussion of the approach described and challenges for the case of adaptive systems are also presented.

Software’s ability to adapt at run-time to changing user needs, system intrusions or faults, changing operational environment, and resource variability has been proposed as a means to cope with the complexity of today’s softwareintensive systems. Such self-adaptive systems can configure and reconfigure themselves, augment their functionality, continually optimize themselves, protect themselves, and recover themselves, while keeping most of their complexity hidden from the user and administrator. In this paper, we present research road map for software engineering of selfadaptive systems focusing on four views, which we identify as essential: requirements, modelling, engineering, and assurances.

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