Do external feedback loops improve the design of self-adaptive systems? A controlled experiment

Abstract

Abstract-Providing high-quality software in the face of uncertainties, such as dealing with new user needs, changing availability of resources, and faults that are difficult to predict, raises fundamental challenges to software engineers. These challenges have motivated the need for self-adaptive systems. One of the primary claimed benefits of self-adaptation is that a design with external feedback loops provide a more effective engineering solution for self-adaptation compared to a design with internal mechanisms. While many efforts indicate the validity of this claim, to the best of our knowledge, no controlled experiments have been performed that provide scientifically founded evidence for it. Such experiments are crucial for researchers and engineers to underpin their claims and improve research. In this paper, we report the results of a controlled experiment performed with 24 final-year students of a Master in Software Engineering program in which designs based on external feedback loops are compared with designs based on internal mechanisms. The results show that applying external feedback loops can reduce control flow complexity and fault density, and improve productivity. We found no evidence for a reduction of activity complexity.

Self-managing Internet of Things

“…Self-adaptation can be considered from two perspectives [30]: (1) the ability of a system to adjust its behaviour in response to the perception of the environment and the system itself [3,15]; the self prefix indicates that the system decides and adapts autonomously (i.e., without or with minimal interference of humans) [2], and (2) the mechanisms that are used to realises self-adaptation, typically by means of a closed feedback loop [8,1,32], i.e. there is an explicit separation between a part of the system that deals with the domain concerns (goals for which the system is built) and a part that deals the adaptation concerns (the way the system realises its goals under changing conditions).…”

Adaptive GC-Aware Load Balancing Strategy for High-Assurance Java Distributed Systems

“…As defined by multiple authors [23], self-adaptation endows a system to adapt itself autonomously to internal and external changes to achieve particular quality goals in the face of uncertainty. To incorporate self-adaptation to our GC-aware load balancing strategy, we have followed the well-known MAPE-K adaptive model [6].…”

Assessing the benefits of search-based approaches when designing self-adaptive systems: a controlled experiment

“…However, we identified one experiment regarding SA systems design and a number of papers reporting on controlled experiments about software architecture design. In (Weyns et al 2013), the authors report the results of a quasi-experiment that investigates whether the use of external feedback loops (when compared with internal adaptation mechanisms) improves the design of SA systems. The design was evaluated with respect to design complexity (in terms of activity complexity and control flow complexity), fault density, and design productivity.…”