A survey of formal methods in self-adaptive systems

Abstract

One major challenge in self-adaptive systems is to assure the required quality properties. Formal methods provide the means to rigorously specify and reason about the behaviors of self-adaptive systems, both at design time and runtime. To the best of our knowledge, no systematic study has been performed on the use of formal methods in self-adaptive systems. As a result, there is no clear view on what methods have been used to verify self-adaptive systems, and what support these methods offer to software developers. As such insight is important for researchers and engineers, we performed a systematic literature review covering 12 main software engineering venues and 4 journals, resulting in 75 papers used for data collection. The study shows that the attention for selfadaptive software systems is gradually increasing, but the number of studies that employ formal methods remains low. The main focus of formalization is on modeling and reasoning. Model checking and theorem proving have gained limited attention. The main concerns of interest in formalization of self-adaptation are efficiency/performance and reliability. Important adaptation concerns, such as security and scalability, are hardly considered. To verify the concerns of interest, a set of new properties are defined, such as interference freedom, responsiveness, mismatch, and loss-tolerance. A relevant part of the studies use formal methods at runtime, but the use is limited to modeling and analysis. Formal methods can be applied to other runtime activities of self-adaptation, and there is a need for lightweight tools to support runtime verification.

Automated control of multiple software goals using multiple actuators

“…One great challenge of self-adaptation is ensuring its effectiveness and dependability [13,19,56]. Control theory has defined a variety of techniques for controlling the behavior of physical plants, and its formal framework serves as a basis for a variety of software adaptation mechanisms [8,12,17,18,23].…”

An overview of self-adaptive technologies within virtual reality training

“…Formal approaches to self-adaptation within software provide approaches to thoroughly identify behaviours of adaptive software and their explanations both at design time and run time (Weyns et al, 2012).…”

“…Generally self-adaptive systems comprise two sections: (1) dealing with domain functionality which is a managed system, and (2) adaptation which is a managing system, which modifies the managed system to achieve quality objectives (Weyns et al, 2012).…”

Automated multi-objective control for self-adaptive software design

“…Formal methods are often used to build self-adaptive systems because of their ability of providing mathematical guarantees on both the effectiveness and the dependability of the adaptation mechanism [29]. Among those methods, control theory [6,[30][31][32] has been recognized by the software engineering community as a solution to meet quality of service requirements despite unpredictable changes in the execution environment.…”