Trusted product lines

This thesis describes research undertaken into the application of software product line approaches to the development of high-integrity, embedded real-time software systems that are subject to regulatory approval/certification. The motivation for the research arose from a real business need to reduce cost and lead time of aerospace software development projects. The thesis hypothesis can be summarised as follows: It is feasible to construct product line models that allow the specification of required behaviour within a reference architecture that can be transformed into an effective product implementation, whilst enabling suitable supporting evidence for certification to be produced. The research concentrates on the following four main areas: 1. Construction of an argument framework in which the application of product line techniques to high-integrity software development can be assessed and critically reviewed. 2. Definition of a product-line reference architecture that can host components containing variation. 3. Design of model transformations that can automatically instantiate products from a set of components hosted within the reference architecture. 4. Identification of verification approaches that may provide evidence that the transformations designed in step 3 above preserve properties of interest from the product line model into the product instantiations. Together, these areas form the basis of an approach we term “Trusted Product Lines”. The approach has been evaluated and validated by deployment on a real aerospace project; the approach has been used to produce DO-178B/ED-12B Level A applications of over 300 KSLOC in size. The effect of this approach on the software development process has been critically evaluated in this thesis, both quantitatively (in terms of cost and relative size of process phases) and qualitatively (in terms of software quality). The “Trusted Product Lines” approach, as described within the thesis, shows how product line approaches can be applied to high-integrity software development, and how certification evidence created and arguments constructed for products instantiated from the product line. To the best of our knowledge, the development and effective application of product line techniques in a certification environment is novel and unique

Engineering Delta Modeling Languages

Delta modeling is a modular, yet flexible approach to capture spatial and temporal variability by explicitly representing the differences between system variants or versions. The conceptual idea of delta modeling is language-independent. But, in order to apply delta modeling for a concrete language, so far, a delta language had to be manually developed on top of the base language leading to a large variety of heterogeneous language concepts. In this paper, we present a process that allows deriving a delta language from the grammar of a given base language. Our approach relies on an automatically generated language extension that can be manually adapted to meet domain-specific needs. We illustrate our approach using delta modeling on a textual variant of statecharts.Comment: 10 pages, 8 figures. Proceedings of the 17th International Software Product Line Conference, Tokyo, September 2013, pp.22-31, ACM, 201

Composition and Self-Adaptation of Service-Based Systems with Feature Models

The adoption of mechanisms for reusing software in pervasive systems has not yet become standard practice. This is because the use of pre-existing software requires the selection, composition and adaptation of prefabricated software parts, as well as the management of some complex problems such as guaranteeing high levels of efficiency and safety in critical domains. In addition to the wide variety of services, pervasive systems are composed of many networked heterogeneous devices with embedded software. In this work, we promote the safe reuse of services in service-based systems using two complementary technologies, Service-Oriented Architecture and Software Product Lines. In order to do this, we extend both the service discovery and composition processes defined in the DAMASCo framework, which currently does not deal with the service variability that constitutes pervasive systems. We use feature models to represent the variability and to self-adapt the services during the composition in a safe way taking context changes into consideration. We illustrate our proposal with a case study related to the driving domain of an Intelligent Transportation System, handling the context information of the environment.Work partially supported by the projects TIN2008-05932, TIN2008-01942, TIN2012-35669, TIN2012-34840 and CSD2007-0004 funded by Spanish Ministry of Economy and Competitiveness and FEDER; P09-TIC-05231 and P11-TIC-7659 funded by Andalusian Government; and FP7-317731 funded by EU. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

A heuristic-based approach to code-smell detection

Encapsulation and data hiding are central tenets of the object oriented paradigm. Deciding what data and behaviour to form into a class and where to draw the line between its public and private details can make the difference between a class that is an understandable, flexible and reusable abstraction and one which is not. This decision is a difficult one and may easily result in poor encapsulation which can then have serious implications for a number of system qualities. It is often hard to identify such encapsulation problems within large software systems until they cause a maintenance problem (which is usually too late) and attempting to perform such analysis manually can also be tedious and error prone. Two of the common encapsulation problems that can arise as a consequence of this decomposition process are data classes and god classes. Typically, these two problems occur together – data classes are lacking in functionality that has typically been sucked into an over-complicated and domineering god class. This paper describes the architecture of a tool which automatically detects data and god classes that has been developed as a plug-in for the Eclipse IDE. The technique has been evaluated in a controlled study on two large open source systems which compare the tool results to similar work by Marinescu, who employs a metrics-based approach to detecting such features. The study provides some valuable insights into the strengths and weaknesses of the two approache