Generating natural language specifications from UML class diagrams

Early phases of software development are known to be problematic, difficult to manage and errors occurring during these phases are expensive to correct. Many systems have been developed to aid the transition from informal Natural Language requirements to semistructured or formal specifications. Furthermore, consistency checking is seen by many software engineers as the solution to reduce the number of errors occurring during the software development life cycle and allow early verification and validation of software systems. However, this is confined to the models developed during analysis and design and fails to include the early Natural Language requirements. This excludes proper user involvement and creates a gap between the original requirements and the updated and modified models and implementations of the system. To improve this process, we propose a system that generates Natural Language specifications from UML class diagrams. We first investigate the variation of the input language used in naming the components of a class diagram based on the study of a large number of examples from the literature and then develop rules for removing ambiguities in the subset of Natural Language used within UML. We use WordNet,a linguistic ontology, to disambiguate the lexical structures of the UML string names and generate semantically sound sentences. Our system is developed in Java and is tested on an independent though academic case study

Learning Moore Machines from Input-Output Traces

The problem of learning automata from example traces (but no equivalence or membership queries) is fundamental in automata learning theory and practice. In this paper we study this problem for finite state machines with inputs and outputs, and in particular for Moore machines. We develop three algorithms for solving this problem: (1) the PTAP algorithm, which transforms a set of input-output traces into an incomplete Moore machine and then completes the machine with self-loops; (2) the PRPNI algorithm, which uses the well-known RPNI algorithm for automata learning to learn a product of automata encoding a Moore machine; and (3) the MooreMI algorithm, which directly learns a Moore machine using PTAP extended with state merging. We prove that MooreMI has the fundamental identification in the limit property. We also compare the algorithms experimentally in terms of the size of the learned machine and several notions of accuracy, introduced in this paper. Finally, we compare with OSTIA, an algorithm that learns a more general class of transducers, and find that OSTIA generally does not learn a Moore machine, even when fed with a characteristic sample

A Retrospective Look at the Monitoring and Checking (MaC) Framework

The Monitoring and Checking (MaC) project gave rise to a framework for runtime monitoring with respect to formally specified properties, which later came to be known as runtime verification. The project also built a pioneering runtime verification tool, Java-MaC, that was an instantiation of the approach to check properties of Java programs. In this retrospective, we discuss decisions made in the design of the framework and summarize lessons learned in the course of the project

Using a Formal Description Technique to Model Aspects of a Global Air Traffic Telecommunications Network

Aspects of a draft version of the Aeronautical Telecommunications Network (ATN) Standards and Recommended Practices (SARPs) under development by ISO-compliant committees of the International Civil Aviation Organization (ICAO) have been mathematically modelled using a formal description technique. The ATN SARPs are a specification for a global telecommunications network for air traffic control systems. A version of Harel's statecharts formalism embedded within a machine readable typed predicate logic has been used as a formal description technique to construct this mathematical model. Our model has been `typechecked' to partially validate the internal consistency of the specification. The work described in this paper has already uncovered some problems in the draft SARPs, and will provide a basis for follow-on efforts to apply formal analysis methods such as model-checking and symbolic execution to aspects of the ATN SARPs. The success of this approach suggests that typed predicate logi..

Verification of Scheme Plans Using CSP || B

This paper presents a tool-supported approach to graphically editing scheme plans and their safety verification. The graphical tool is based on a domain-specific language which is used as a basis for a transformation to a CSP||B formal model of a scheme plan. The models produce use a variety of abstraction techniques that make the analysis of large scale plans feasible

Verification and validation principles from a systems perspective

This chapter introduces concepts and principles associated with the verification and validation of simulation models, mainly in the context of models of complete systems from a systems-modelling perspective. The word “verification” is used here to describe testing processes to establish whether a computer-based representation correctly describes the underlying mathematical, logical and theoretical structure of the model. The word “validation” is used to describe procedures for establishing whether the model fidelity is adequate for the purposes of the given application. Verification is internal to the model and the computer-based representation while validation processes involve information external to the model, normally using data or observations from the corresponding real system. The goal of the testing process for a simulation model must always be to establish the extent to which a model has the quality and credibility required for the intended application. These model testing processes, involving both verification and validation, are inherently iterative