Assessing and improving quality of QVTo model transformations

We investigate quality improvement in QVT operational mappings (QVTo) model transformations, one of the languages defined in the OMG standard on model-to-model transformations. Two research questions are addressed. First, how can we assess quality of QVTo model transformations? Second, how can we develop higher-quality QVTo transformations? To address the first question, we utilize a bottom–up approach, starting with a broad exploratory study including QVTo expert interviews, a review of existing material, and introspection. We then formalize QVTo transformation quality into a QVTo quality model. The quality model is validated through a survey of a broader group of QVTo developers. We find that although many quality properties recognized as important for QVTo do have counterparts in general purpose languages, a number of them are specific to QVTo or model transformation languages. To address the second research question, we leverage the quality model to identify developer support tooling for QVTo. We then implemented and evaluated one of the tools, namely a code test coverage tool. In designing the tool, code coverage criteria for QVTo model transformations are also identified. The primary contributions of this paper are a QVTo quality model relevant to QVTo practitioners and an open-source code coverage tool already usable by QVTo transformation developers. Secondary contributions are a bottom–up approach to building a quality model, a validation approach leveraging developer perceptions to evaluate quality properties, code test coverage criteria for QVTo, and numerous directions for future research and tooling related to QVTo quality

Formal verification of Chi models using PHAVer

The hybrid Chi (x) language is a formalism for modeling, simulation and verification of hybrid systems. One of the most widely known hybrid system formalisms is that of hybrid automata. The formal translation of x to hybrid automata enables verification of x specifications using existing hybrid automata based veri??cation tools. In this paper, we describe the translation from x to hybrid automata, and the relation between hybrid automata and the linear hybrid I/O automata that are used for the verification tool PHAVer (Polyhedral Hybrid Automaton Verifyer). In the case study, we translate a x specification to a linear hybrid I/O automaton, and use PHAVer to verify properties

Model-Based Engineering of Supervisory Controllers using CIF

In the Model-Based Engineering (MBE) paradigm, models are the core elements in the design process of a system from its requirements to the actual implementation of the system. By means of Supervisory Control Theory (SCT), supervisory controllers (supervisors) can be synthesized instead of designingthem manually. In this paper, a framework based on the Compositional Interchange Format for hybrid systems (CIF) has been developed that integrates the MBE andthe SCT paradigms. To illustrate the framework, an industrial-size case study has been performed: 'synthesis of a supervisory controller for the patientsupport system of an MRI scanner'. In this case study, we address 1) modelling of the components and the control requirements; 2) synthesis of the supervisor;3) simulation of the synthesized supervisor and a hybrid model of the plant; and 4) real-time, simulation based control of the supervisor and the actual patient support system of the MRI scanner

Supervisory control synthesis for a patient support system

The increasing complexity of systems and the increasing market pressure necessitate the need for methods to maximize reuse and to minimize the effort to develop new systems. Modelbased engineering is one of these methods. It uses models and model-based techniques in the development process to analyze and synthesize systems and components. In this report, Supervisory Control Synthesis is used to design a supervisory controller for a patient support system. This system is used to position a patient in a Magnetic Resonance Imaging (MRI) scanner. To improve the evolvability of the design, the uncontrolled system and the control requirements are modeled independently, using small loosely coupled minimal restrictive automata. An implementation of the synthesized supervisor is realized by means of a transformation to an automaton in the Compositional Interchange Format (CIF). The supervisor is validated by means of hardware-in-the-loop simulation, using the real patient support system

Evolution specification evaluation in industrial MDSE ecosystems

Domain-specific languages (DSLs) allow users to model systems using concepts from a specific domain. Evolution of DSLs triggers co-evolution of models developed in these languages. When the number of models that needs to co-evolve increases, so does the required effort to do so. This is called the co-evolution problem. We have investigated the extent of the co-evolution problem at ASML [1], provider of lithography equipment for the semiconductor industry. Here we have described the structure and evolution of a large-scale ecosystem of DSLs. We have observed that due to the large number of artifacts that require coevolutionary activity, manual solutions have become unfeasible, and an automated approach is required. A popular approach for automating co-evolution is the operator-based approach. In this paper we have evaluated the operator-based approach on a large-scale industrial case-study of twenty-two DSLs and 95 model-to-model transformations with a revision history of over three years, and have revealed deficiencies in existing operator libraries. To address these deficiencies we have presented a topdown methodology to derive a complete set of operators