Steve Riddle

Tailoring Traceability Information to Business Needs

Several surveys over the past 20 years have observed that traceability information is often poorly recorded. In previous work we have argued that this is a result of many requirements traceability systems failing to provide any direct benefit to the development process. In this paper we describe an application of traceability by a company, with a resulting increase in profitability as well as other benefits for the development engineer, project management and customer

Protective Wrapper Development: A Case Study

We have recently proposed a general approach to engineering protective wrappers as a means of detecting errors or unwanted behaviour in systems employing an OTS (Off-The-Shelf) item, and launching appropriate recovery actions. This paper presents results of a case study in protective wrapper development, using a Simulink model of a steam boiler system together with an OTS PID (Proportional, Integral and Derivative) controller. The protective wrappers are developed for the model of the system in such a way that they allow detection and tolerance of typical errors caused by unavailability of signals, violations of constraints, and oscillations.

Risk Management for Web and Distributed Software Development Projects

The level of complexity and risks associated with software have been increasing in line with the growth of the software industry. Modern software development, with an emphasis on web and distributed development, presents specific challenges and risk areas to the software industry which need to be considered and managed. In this paper we survey a number of software risk management approaches and identify weaknesses such as the treatment of culture issues, geographical location, and process and product perspectives. These weaknesses must be tackled in order to accommodate the continuously evolving challenges to web and distributed software development and to cover some perspectives of the software industry which have not been well covered up to now. This work is a part of PhD research at Newcastle University (UK) to develop an improved approach to measure and control web and distributed development risks.

Interface specification for system-of-systems architectures

Establishing that a system-of-systems (SoS) architecture respects global SoS-level properties is complex. Recording explicit technical interfaces at the boundaries of constituent systems would facilitate this, but support for the description of such interfaces is limited in current widely-used architectural notations. This paper identifies research challenges that arise from using the combination of SysML and the formal notation VDM to describe the interface specifications recorded at the boundaries of the constituent systems. The approach is illustrated with a case study based on an emergency services SoS.

Practice-oriented courses in formal methods using VDM ++

We describe the design and delivery of two courses that aim to develop skills of use to students in their subsequent professional practice, whether or not they apply formal methods directly. Both courses emphasise skills in model construction and analysis by testing rather than formal verification. The accessibility of the formalism is enhanced by the use of established notations (VDM-SL and VDM++). Motivation is improved by using credible examples drawn from industrial projects, and by using an industrial-strength tool set. We present examples from the courses and discuss student evaluation and examination performance. We stress the need for exercises and tests to support the development of abstraction skills.

Contract-based modelling and analysis technologies for Systems-of-Systems

Despite the opportunities offered by Systems-of-Systems engineering, there is a lack of models and tools to support dependable decision-making during design and evolution. Such models should combine the rigour needed for reliable analysis with the abstractions needed to describe heterogeneous and independent constituent systems, and the contracts between them. Models should also provide a basis for communication between their diverse stakeholders. Suitable models and tools have the potential to enable the analysis of local and global properties by a range of techniques including simulation and formal verification. The papers in this invited session will provide participants with an understanding of the state of the art and the research directions in rigorous model-based approaches to SoS engineering, through the support of COMPASS, the European Commissions FP7 project on “Comprehensive Modelling and Analysis for Advanced Systems of Systems”.

Meta-modelling approach to traceability for avionics: a framework for managing the engineering of computer based aerospace systems

Traceability is the common term for mechanisms to record and navigate relationships between artifacts produced by development and assessment processes. Effective management of these relationships is crucial to projects involving the development of complex, safety critical computer based aerospace systems. Practitioners use a range of notations to model such systems. Most have tool support, though a lack of well defined approaches to integration limits traceability between their respective data sets. This paper proposes a framework known as MATrA (Meta-modelling Approach to Traceability for Avionics) that enables traceability links to be established and consistency maintained across data from potentially disjoint tools.