Mixing Formal and Informal Model Elements for Tracing Requirements

Tracing between informal requirements and formal models is challenging. A method for such tracing should permit to deal efficiently with changes to both the requirements and the model. A particular challenge is posed by the persisting interplay of formal and informal elements. In this paper, we describe an incremental approach to requirements validation and systems modelling. Formal modelling facilitates a high degree of automation: it serves for validation and traceability. The foundation for our approach are requirements that are structured according to the WRSPM reference model. We provide a system for traceability with a state-based formal method that supports refinement. We do not require all specification elements to be modelled formally and support incremental incorporation of new specification elements into the formal model. Refinement is used to deal with larger amounts of requirements in a structured way. We provide a small example using Problem Frames and Event-B to demonstrate our approach

Validating the requirements and design of a hemodialysis machine using iUML-B, BMotion Studio, and co-simulation

We present a formal specification of a hemodialysis machine (HD machine) using Event-B. We model the HD machine using iUML-B state-machines and class diagrams and build a corresponding BMotion Studio visualisation. We focus on validation using (i) diagrams to aid the modelling of the sequential properties of the requirements, and (ii) ProB-based animation and visualisation tools to explore the system’s behaviour. Some of the safety properties involve dynamic behaviour which is difficult to verify in Event-B. For these properties we use co-simulation tools to validate against a continuous model of the physical behaviour

Formal specification of a Haemodialysis Machine (HD Machine) using Event-B

This archive contains a formal specification of a haemodialysis machine (HD machine) in Event-B using the Rodin Toolset. We utilise ProR for structuring and tracking requirements. We model the HD machine using iUML-B state-machines and class diagrams, and build a corresponding BMotion Studio visualisation. For verification, we use both theorem proving and model checking techniques. We validate the design of the system using (i) diagrams to aid the modelling of the sequential properties of the requirements, and (ii) ProB-based animation and visualisation tools to explore the system&#39;s behaviour. Some of the safety properties involve dynamic behaviour which is difficult to verify in Event-B. For these properties we use (iii) co-simulation tools to validate against a continuous model of the physical behaviour. Assigned DOI: 10.5258/SOTON/401360</span

Validating and verifying the requirements and design of a haemodialysis machine using the rodin toolset

We present a formal specification and analysis of a haemodialysis machine (HD machine) in Event-B using the Rodin Toolset. The medical device domain is a particularly complex multidisciplinary field involving disparate branches of engineering, biological and medical fields as well as a critical patient-machine interface. Requirements include safety properties, process steps, human-machine interfaces, timing constraints, dynamic control algorithms, and design features. Our aim is to demonstrate that the Event-B based modelling, verification and validation tools deal with the variety of requirements involved in a typical medical device. We utilise ProR for structuring and tracking requirements. We model the HD machine using iUML-B state-machines and class diagrams, and build a corresponding BMotion Studio visualisation. For verification, we use both theorem proving and model checking techniques. We validate the design of the system using (i) diagrams to aid the modelling of the sequential properties of the requirements, and (ii) ProB-based animation and visualisation tools to explore the system's behaviour. Some of the safety properties involve dynamic behaviour which is difficult to verify in Event-B. For these properties we use (iii) co-simulation tools to validate against a continuous model of the physical behaviour. We conclude that the Event-B based modelling tools are particularly rich in verification and validation techniques and with the help of supporting tools for requirements tracking, are able to address the different kinds of requirements in a medical device