Abstract The extended hierarchical state transition matrices (EHSTMs) are a table-based modelling language frequently used in industry for specifying behaviours of systems. However, assuring correctness, i.e., having a design satisfy certain desired properties, is a non-trivial task. To address this problem, a model checker dedicated to EHSTMs called Garakabu2 has been developed. However, there is no formal justification for Garakabu2, since its semantics has never been fully formalised. In this paper, we give a formal semantics to EHSTMs by translating them into CSP, Communicating Sequential Processes. Among the variants of CSP, we use CSP#, which is the modelling language used by PAT model checker, as a target of translation. Our semantics covers most of the features supported by Garakabu2. We manually translate the small examples of EHSTMs to CSP#, and verify them by PAT. We also verify the examples directly using Garakabu2 and show that the results are same. The experiments also indicate that verification using our translation and PAT is much faster than that of Garakabu2 in some cases.

Formal Methods has been recognized as a rigorous development methodology for hardware and software systems. In particular, model checking is well accepted as an effective verification method for hardware systems, safety/missioncritical systems and embedded systems. To foster this technology in industry, we recognize a need to develop educational materials to enhance learning the technology by students and practitioners. However, there are neither standard guidelines nor instructions how to teach this technology. In this paper, we will present the first draft of a body of knowledge on model checking called MCBOK to address this issue, and present lessons learned from its development experience.

Hierarchical State Transition Matrix (HSTM) is a table-based modeling language for developing designs of software systems. We have proposed a Satisfiability Modulo Theory (SMT) based Bounded Model Checking (BMC) approach in [1] to provide formal verification supports for conducting rigorous and automatic analysis to improve reliability of HSTM designs. In this paper, we continue that work by developing and evaluating approaches to accelerating BMC of HSTM designs. The approaches center around an unrolled Bounded Reach ability Tree (BRT) of a HSTM design that is built with stateless explicit state exploration. Specifically, reach ability of invalid cells (representing undesired states) of a HSTM design, which occurs within the bound concerned, could be discovered during construction of the BRT, and furthermore, if no such occurrence, the constructed BRT could be utilized to rule out unnecessary subformulas of a BMC instance for verification of LTL properties. We have implemented these approaches in a tool called Garakabu2 with the state-of-the-art SMT solver CVC3 as its back-ended solver. Our preliminary experiments show that verification could be accelerated substantially.

This paper discusses the Top SE program established to bridge the industry-academia gap. The program features extensive use of software engineering tools, not only to introduce students to the tools, but also as a conduit for learning the techniques and guidelines needed to apply the tools to practical software development situations. The curriculum is organized around practical problems mainly from the area of digital home appliances and focuses on upper stream software development processes. The Top SE program is developed and operated by a close collaboration between industry and academia. We illustrate our discussion with examples from one of the courses, verification of design models, which takes up model checking technologies, including three specific tools: SPIN, SMV, and LTSA.

Formal methods and requirements analysis are techniques for developing complex systems. However, there is little research on reconciling the requirements phase with the formal specification phase. To bridge this gap, we propose a formal specification generator based on model transformation techniques. This tool transforms KAOS models (requirements specifications) into VDM++ formal specifications. Our generator enables consistent and effective software development activities.

Software systems have become increasingly distributed, dynamic and mobile. The complex state and dynamic interfaces of software components and their concurrent interactions provide challenging research issues in system specification and design. An effective combination of structured state-based formalism and dynamic action-based calculus may be a good solution for modeling complex distributed mobile systems. In this paper, we investigate the semantic links between Object-Z and /spl pi/ calculus and consequently introduce a powerful specification technique PiOZ that brings the strengths of the two together. The operational semantics of PiOZ integrates state transition semantics of Object-Z and /spl pi/-calculus reduction rules. The typing rules of PiOZ are developed and reasoning of a system property is presented.

Frameworks are increasingly being recognised as very useful components in the emerging paradigm of component-based software development (CBD). They are widely accepted as better units of reuse than objects. The CBD methodology Catalysis, for instance, uses frameworks. However, at present, Catalysis frameworks are described only informally, which means we cannot reason formally about frameworks, in particular their composition, and thereby their reuse. For this, we would need to specify frameworks (and their composition) formally. In this paper, we describe our approach for doing so.

We introduce a new CCS-like process calculus for mobile agents called the AP (Agent and Place)-calculus. The calculus is based on the agent-place model which is a basis for mobility of an agent language Telescript by White (1996). A number of mobile calculi such as /spl pi/-calculus, Mobile Ambients have been proposed as foundational calculi which are intended to describe the canonical model of computation. However the AP-calculus is not developed as a foundational calculus, but rather as a practical formalism for specifying and verifying mobile applications such as electronic commerce. We present the AP-calculus and its operational semantics and give a simple example specification of an intelligent agent roaming about the network to find out the information in order to demonstrate its applicability.

Presents a formal method which combines the Z notation and value-passing CCS (Calculus of Communicating Systems) for specifying concurrent systems. In order to provide a sound theoretical basis for the method, the state-based semantics for value-passing CCS is given. The main characteristic of the semantics is its ability in describing the evolution of processes and transitions of states simultaneously. We also present a Hennessy-Milner logic based on that semantics, which enables us to express properties such as liveness and safety ascribed both to states and to actions.

The paper proposes an extended notation of Z by which one can explicitly specify the intended behavior of operation schemas in the form of state transitions. The notation is based on a labeled transition system which is tractable to analyse the operational behavior of Z. We mainly focus on the semantic framework which enables us to express constraints both locally and globally. Simple examples are presented and some research issues on operational interpretation of schemas are discussed with respect to our semantic framework.