TURTLE: Four Weddings and a Tutorial

The paper discusses an educational case study of protocol modelling in TURTLE, a real-time UML profile supported by the open source toolkit TTool. The method associated with TURTLE is step by step illustrated with the connection set up and handover procedures defined for the Future Air navigation Systems. The paper covers the following methodological stages: requirement modeling, use-case driven and scenario based analysis, object-oriented design and rapid prototyping in Java. Emphasis is laid on the formal verification of analysis and design diagrams

Verifying service continuity in a satellite reconfiguration procedure: application to a satellite

The paper discusses the use of the TURTLE UML profile to model and verify service continuity during dynamic reconfiguration of embedded software, and space-based telecommunication software in particular. TURTLE extends UML class diagrams with composition operators, and activity diagrams with temporal operators. Translating TURTLE to the formal description technique RT-LOTOS gives the profile a formal semantics and makes it possible to reuse verification techniques implemented by the RTL, the RT-LOTOS toolkit developed at LAAS-CNRS. The paper proposes a modeling and formal validation methodology based on TURTLE and RTL, and discusses its application to a payload software application in charge of an embedded packet switch. The paper demonstrates the benefits of using TURTLE to prove service continuity for dynamic reconfiguration of embedded software

Modelling mobile health systems: an application of augmented MDA for the extended healthcare enterprise

Mobile health systems can extend the enterprise computing system of the healthcare provider by bringing services to the patient any time and anywhere. We propose a model-driven design and development methodology for the development of the m-health components in such extended enterprise computing systems. The methodology applies a model-driven design and development approach augmented with formal validation and verification to address quality and correctness and to support model transformation. Recent work on modelling applications from the healthcare domain is reported. One objective of this work is to explore and elaborate the proposed methodology. At the University of Twente we are developing m-health systems based on Body Area Networks (BANs). One specialization of the generic BAN is the health BAN, which incorporates a set of devices and associated software components to provide some set of health-related services. A patient will have a personalized instance of the health BAN customized to their current set of needs. A health professional interacts with their\ud patients¿ BANs via a BAN Professional System. The set of deployed BANs are supported by a server. We refer to this distributed system as the BAN System. The BAN system extends the enterprise computing system of the healthcare provider. Development of such systems requires a sound software engineering approach and this is what we explore with the new methodology. The methodology is illustrated with reference to recent modelling activities targeted at real implementations. In the context of the Awareness project BAN implementations will be trialled in a number of clinical settings including epilepsy management and management of chronic pain

Rigorous object-oriented analysis

Object-oriented methods for analysis, design and programming are commonly used by software engineers. Formal description techniques, however, are mainly used in a research environment. We have investigated how rigour can be introduced into the analysis phase of the software development process by combining object-oriented analysis (OOA) methods with formal description techniques. The main topics of this investigation are a formal interpretation of the OOA constructs using LOTOS, a mathematical definition of the basic OOA concepts using a simple denotational semantics and a new method for object- oriented analysis that we call the Rigorous Object-Oriented Analysis method (ROOA). The LOTOS interpretation of the OOA concepts is an intrinsic part of the ROOA method. It was designed in such a way that software engineers with no experience in LOTOS, can still use ROOA. The denotational semantics of the concepts of object-oriented analysis illuminates the formal syntactic transformations within ROOA and guarantees that the basic object- oriented concepts can be understood independently of the specification language we use. The ROOA method starts from a set of informal requirements and an object model and produces a formal object-oriented analysis model that acts as a requirements specification. The resulting formal model integrates the static, dynamic and functional properties of a system in contrast to existing OOA methods which are informal and produce three separate models that are difficult to integrate and keep consistent. ROOA provides a systematic development process, by proposing a set of rules to be followed during the analysis phase. During the application of these rules, auxiliary structures are created to help in tracing the requirements through to the final formal model. As LOTOS produces executable specifications, prototyping can be used to check the conformance of the specification against the original requirements and to detect inconsistencies, omissions and ambiguities early in the development process

Formal Specification and Verification of Fully Asynchronous Implementations of the Data Encryption Standard

This paper presents two formal models of the Data Encryption Standard (DES), a first using the international standard LOTOS, and a second using the more recent process calculus LNT. Both models encode the DES in the style of asynchronous circuits, i.e., the data-flow blocks of the DES algorithm are represented by processes communicating via rendezvous. To ensure correctness of the models, several techniques have been applied, including model checking, equivalence checking, and comparing the results produced by a prototype automatically generated from the formal model with those of existing implementations of the DES. The complete code of the models is provided as appendices and also available on the website of the CADP verification toolbox.Comment: In Proceedings MARS 2015, arXiv:1511.0252

Compositional Performance Modelling with the TIPPtool

Stochastic process algebras have been proposed as compositional specification formalisms for performance models. In this paper, we describe a tool which aims at realising all beneficial aspects of compositional performance modelling, the TIPPtool. It incorporates methods for compositional specification as well as solution, based on state-of-the-art techniques, and wrapped in a user-friendly graphical front end. Apart from highlighting the general benefits of the tool, we also discuss some lessons learned during development and application of the TIPPtool. A non-trivial model of a real life communication system serves as a case study to illustrate benefits and limitations