John Fitzgerald

John Fitzgerald, Tomohiro Oda, Hugo Daniel Macedo

This volume contains the papers presented at the 18th International Overture Workshop, held online on 7th December 2020. This event was the latest in a series of workshops around the Vienna Development Method (VDM), the open-source project Overture, and related tools and formalisms. VDM is one of the longest established formal methods for systems development. A lively community of researchers and practitioners has grown up in academia and industry has grown around the modelling languages (VDM-SL, VDM++, VDM-RT, CML) and tools (VDMTools, Overture, Crescendo, Symphony, the INTO-CPS chain, and ViennaTalk). Together, these provide a platform for work on modelling and analysis technology that includes static and dynamic analysis, test generation, execution support, and model checking. This workshop provided updates on the emerging technology of VDM/Overture, including collaboration infrastructure, collaborative modelling and co-simulation for Cyber-Physical Systems.

Peter Gorm Larsen, Hugo Daniel Macedo, John Fitzgerald et al.

Businesses, particularly small and medium-sized enterprises, aiming to start up in Model-Based Design (MBD) face difficult choices from a wide range of methods, notations and tools before making the significant investments in planning, procurement and training necessary to deploy new approaches successfully. In the development of Cyber-Physical Systems (CPSs) this is exacerbated by the diversity of formalisms covering computation, physical and human processes. In this paper, we propose the use of a cloud-enabled and open collaboration platform that allows businesses to offer models, tools and other assets, and permits others to access these on a pay-per-use basis as a means of lowering barriers to the adoption of MBD technology, and to promote experimentation in a sandbox environment.

Claire Ingram, Steve Riddle, John Fitzgerald et al.

Systems of systems (SoSs) are particularly vulnerable to faults and other threats to their dependability, but frequently inhabit domains that demand high levels of dependability. For this reason fault tolerance analysis is important in SoS engineering. The COMPASS project has previously proposed a Fault Tolerance Architecture Framework (FMAF), consisting of a collection of viewpoints that support systematic reasoning about faults in an SoS at the architectural level. The FMAF has been demonstrated previously with an analysis of an example fault in an emergency response SoS. In this paper we present further examples of the FMAF's practical use, by analysing different types of faults drawn from the same emergency response case study. These example faults exercise different aspects of the FMAF, demonstrate its use in more complex fault modelling scenarios, and raise new questions for further development.