Summary Adaptive systems (ASs) and context‐aware systems (CASs) are able to evaluate their own behaviour and toadaptit when the system fails to accomplish its goals or when better functionality or performance is possible. Ensuring the reliability of ASs and CASs is demanding because failures might have undesirable consequences. Testing ASs and CASs effectively is not trivial because of the inherent characteristics of these systems. The literature lacks a comprehensive review that provides a broad picture of the area; current reviews are outdated and incomplete. The objectives of this study are characterizing the state of the art in AS and CAS testing and discussing approaches, challenges, observed trends, and research limitations and directions. We performed a systematic literature review (SLR) and a thematic analysis of studies, reporting up‐to‐date, refined and extended results when compared with existing reviews. Based on 102 selected studies, we (i) characterized testing approaches by grouping techniques for ASs and CASs; (ii) updated and refined a characterization of testing challenges for ASs and CASs; and (iii) analysed and discussed research trends and implications for AS and CAS testing. There are recurring research concerns regarding AS and CAS testing. Examples are the generation of test cases and built‐in tests. Moreover, we also identified recurring testing challenges such as context monitoring and runtime decisions. Moreover, there are some trends such as model‐based testing and hybrid techniques and some little investigated issues like uncertainty and prediction of changes. All in all, our results may provide guidance for developers and researchers with respect to the practice and the future research on AS and CAS testing.

An adaptive system (AS) evaluates its own behavior and changes it when the evaluation indicates that the system is not accomplishing what it is intended to do, or when better functionality or performance is possible. MAPE-K is a reference model that prescribes the adaptation mechanism of ASs by means of high-level abstractions such as Monitors, Analyzers, Planners and Executors and the relationships among them. Since the abstractions and the relationships provided by MAPE-K are generic, other reference models were proposed focusing on providing lower level abstractions to support software engineers in a more suitable way. However, after the analysis of seven representative ASs, we realized the abstractions prescribed by the existing reference models are not properly implemented, thus leading to architectural drifts. Therefore, in this paper we characterized three of these drifts by describing them with a template and showing practical examples. The three architectural drifts of ASs are Scattered Reference Inputs, Mixed Executors and Effectors, and Obscure Alternatives. We expect that by identifying and characterizing these drifts, we can help software architects improve their design and, as a consequence, increase the reliability of this type of systems.

Architecture-Driven Modernization (ADM) intends to standardize software reengineering by relying on a family of standard metamodels. Knowledge-Discovery Metamodel (KDM) is the main ADM ISO metamodel aiming at representing all aspects of existing legacy systems. One of the internal KDM metamodels is called Structure, responsible for representing architectural abstractions (Layers, Components and Subsystems) and their relationships. Planned Architecture (PA) is an artifact that involves not only the architectural abstractions of the system but also the access rules that must exist between them and be maintained over time. Although PAs are frequently used in Architecture-Conformance Checking processes, up to this moment, there is no contribution showing how to specify and serialize PAs in ADM-based modernization projects. Therefore, in this paper we present an approach that i) involves a DSL (Domain-Specific Language) for the specification of PAs using the Structure metamodel concepts, and ii) proposes a strategy for the serialization of PAs as a Structure metamodel instance without modifying it. We have conducted a comparison between DCL-KDM and other techniques for specifying and generating PAs. The results showed that DCL-KDM is an efficient alternative to to generate instances of the Structure metamodel as a PA and to serialize it.

One of the first steps when reengineering legacy systems into aspect-oriented ones is to identify the crosscutting concerns (CCC) presented in the architecture of the former; a process known as aspect mining. However, this is a time- consuming and error-prone task when conducted manually. In this paper, we present a customizable mining tool, called ComSCId, which searches for the CCC in legacy Java systems in an automatic way. ComSCId owns a repository which stores all the rules used as base for the mining process. In this repository there are pre-defined rules for some ordinary CCC like persistence, buffering and logging. Moreover, the main characteristic of this repository is its flexibility, since it allows adding new rules or customizing the existing ones to specific contexts or domains. We conducted two studies to evaluate ComSCId and we have observed high percentages of identification coverage when using this tool in an incremental way.