The specification-based validation of reliable multicast protocol: Problem Report

Reliable Multicast Protocol (RMP) is a communication protocol that provides an atomic, totally ordered, reliable multicast service on top of unreliable IP multicasting. In this report, we develop formal models for RMP using existing automated verification systems, and perform validation on the formal RMP specifications. The validation analysis help identifies some minor specification and design problems. We also use the formal models of RMP to generate a test suite for conformance testing of the implementation. Throughout the process of RMP development, we follow an iterative, interactive approach that emphasizes concurrent and parallel progress of implementation and verification processes. Through this approach, we incorporate formal techniques into our development process, promote a common understanding for the protocol, increase the reliability of our software, and maintain high fidelity between the specifications of RMP and its implementation

ІНСЕРЦІЙНЕ МОДЕЛЮВАННЯ В ПРОЕКТУВАННІ РОЗПОДІЛЕНИХ СИСТЕМ. \ud INSERTION MODELING IN DISTRIBUTED SYSTEM DESIGN

Стаття описує методологію інсерційного моделювання, її реалізацію та застосування. Інсерційне моделювання являє собою методологію проектування розподілених систем, що управляється моделлю. Ця методологія базується на теорії взаємодіючих агентів та середовищ [1-2] та використовує Basic Protocol Specification Language (BPSL) для представлення специфікацій вимог до розподілених систем. [3-6]. Діаграма Послідовності з пре- та пост-умовами (логічними формулами, що інтерпретуються відповідно до опису середовища) – Базовий Протокол є центральним поняттям цієї мови. Семантика BPSL дозволяє конкретні та абстракті моделі рівних рівнів абстрактності. Моделі визначені як Basic Protocol Specifications (BPS) можуть у подальшому бути використані як для верифікація специфікацій вимог та і для генерації тестових наборів.\ud Інсерційне моделювання підтримується системою VRS (Verification of Requirement Specifications), створеною для компанії Моторола київською групою VRS у співробітництві із ЗАТ Моторола-Санкт-Петербург. Система дозволяє статичний аналіз вимог на основі автоматичного доведення теорем, символьної та дедуктивної перевірки моделей та породження трас для тестування із заданими критеріями покриття. Всі засоби були розроблені на базі формальної семантики BPSL, побудованої відповідно до методології інсерційного моделювання VRS була успішно застосована у великій кількості індустріальних проектів із різних галузей, включаючи телекомунікації, телематику та системи реального часу.----------------------------------\ud The paper describes insertion modeling methodology, its implementation and applications. Insertion modeling is a methodology of model driven distributed system design. It is based on the model of interaction of agents and environments [1-2] and use Basic Protocol Specification Language (BPSL) for the representation of requirement specifications of distributed systems [3-6]. The central notion of this language is the notion of basic protocol – a sequencing diagram with pre- and postconditions, logic formulas interpreted by environment description. Semantics of BPSL allows concrete and abstract models on different levels of abstraction. Models defined by Basic Protocol Specifications (BPS) can be used for verification of requirement specifications as well as for generation of test cases for testing products, developed on the basis of BPS. \ud Insertion modeling is supported by the system VRS (Verification of Requirement Specifications), developed for Motorola by Kiev VRS group in cooperation with Motorola GSG Russia. The system provides static requirement checking on the base of automatic theorem proving, symbolic and deductive model checking, and generation of traces for testing with different coverage criteria. All tools have been developed on a base of formal semantics of BPSL constructed according to insertion modeling methodology. \ud The VRS has been successfully applied to a number of industrial projects from different domains including Telecommunications, Telematics and real time applications.\ud \u

Using formal methods to support testing

Formal methods and testing are two important approaches that assist in the development of high quality software. While traditionally these approaches have been seen as rivals, in recent years a new consensus has developed in which they are seen as complementary. This article reviews the state of the art regarding ways in which the presence of a formal specification can be used to assist testing

JWalk: a tool for lazy, systematic testing of java classes by design introspection and user interaction

Popular software testing tools, such as JUnit, allow frequent retesting of modified code; yet the manually created test scripts are often seriously incomplete. A unit-testing tool called JWalk has therefore been developed to address the need for systematic unit testing within the context of agile methods. The tool operates directly on the compiled code for Java classes and uses a new lazy method for inducing the changing design of a class on the fly. This is achieved partly through introspection, using Java’s reflection capability, and partly through interaction with the user, constructing and saving test oracles on the fly. Predictive rules reduce the number of oracle values that must be confirmed by the tester. Without human intervention, JWalk performs bounded exhaustive exploration of the class’s method protocols and may be directed to explore the space of algebraic constructions, or the intended design state-space of the tested class. With some human interaction, JWalk performs up to the equivalent of fully automated state-based testing, from a specification that was acquired incrementally

Architecting specifications for test case generation

The Specification and Description Language (SDL) together with its associated tool sets can be used for the generation of Tree and Tabular Combined Notation (TTCN) test cases. Surprisingly, little documentation exists on the optimal way to specify systems so that they can best be used for the generation of tests. This paper, elaborates on the different tool supported approaches that can be taken for test case generation and highlights their advantages and disadvantages. A rule based SDL specification style is then presented that facilitates the automatic generation of tests

Addressing performance requirements in the FDT-based design of distributed systems

The development of distributed systems is generally regarded as a complex and costly task, and for this reason formal description techniques such as LOTOS and ESTELLE (both standardized by the ISO) are increasingly used in this process. Our experience is that LOTOS can be exploited at many stages on the design trajectory, from requirements specification to implementation, but that the language elements do not allow direct formalization of performance requirements. To avoid duplication of effort by using two formalisms with distinct approaches, we propose a design method that incorporates performance constraints in an heuristic but effective manner