VALIDATING REQUIREMENTS SPECIFICATIONS STATED IN KNOWLEDGE REPRESENTATION LANGUAGE TEMPLAR

Techniques for analysis and validation of software requirements specifications written in the knowledge representation language Templar are presented. Templar specifications are analyzed in terms of ambiguity, non-minimality, contradiction, incompleteness, and redundancy. Since Templar is a powerful knowledge representation language supporting a rich set of modeling primitives, it is difficult to reason directly on Templar specifications. To solve this problem, Templar specifications are mapped into equivalent temporal logic programs which are analyzed in terms the criteria listed above. However, it is hard to reason about Templar specifications because some of the criteria cannot be formally proven, and the verification of other criteria constitute undecidable or intractable problems. To overcome these difficulties, we consider a set of tractable conditions for each criteria, which serve as "alarms" for the user. If a condition is violated then it means that the specification either definitely has or potentially can have a problem. Furthermore, the user is notified about the source and the nature of the problem in certain cases.Information Systems Working Papers Serie

Issues and Challenges in Business Rule Based Information Systems Development

An explicit manipulation of business rules in information systems development (ISD) is an old domain. There were many attempts in the last two decades to define how the rules should be dealt with throughout the ISD activities. Despite many results that have been achieved, several questions regarding business rule manipulation within ISD remain unresolved and present challenges for future research. The objective of this paper is to discuss these challenges and where possible to point out some directions for potential solution

Constraint Diagrams: Visualizing Assertions in OO Modelling

Describes a notation, constraint diagrams, which allows pre/post conditions and invariants to be expressed visually, rather than in the notation of mathematical logic. The notation is explored through a small case study (a library system). Some conclusions are drawn about the use of the notation in modelling, and its possible impact on tools and semantics. This report has been split into two and considerable revised and updated: Kent (1997b), Kent (1997c)

The stability of money demand, its interest sensitivity, and some implications for money as a policy guide

An examination of recent empirical research on money demand, which states that the interest elasticity of money demand is greater than most economists previously thought. The author discusses the policy implications of this research for both the M1 and M2 measures.Money ; Velocity of money ; Monetary policy

TEMPLAR: A KNOWLEDGE-BASED LANGUAGE FOR SOFTWARE SPECIFICATIONS USING TEMPORAL LOGIC

A software specification language Templar is defined. The language is based on temporal logic and on the Activity-Event-Condition-Activity model of a rule which is an extension of the Event-Condition-Activity model in active databases. The language supports a rich set of modeling primitives, including rules, procedures, temporal logic operators, events, activities, hierarchical decomposition of activities, and parallelism, combined together in a coherent system. The development of the language was guided by the following objectives: specifications written in Templar should be easy for the non-computer oriented users to understand, should have formal syntax and semantics, and it should be easy to map them into a broad range of design specifications.Information Systems Working Papers Serie

Use of Scenarios for Validation of Conceptual Specifications

The development of a large information system is generally regarded as one of the most complex activities undertaken by organisations. Boehm has reported that although only 6 percent of project's cost and between 9 and 12 percent of the project's duration is spent in the requirements phase, it costs between five and ten times more to repair errors during coding than during the requirements phase. Development and customer organisations could save a lot of time and money if they could detect and correct a fraction of the errors then, rather than later. This task is supported by the process of verification and validation of requirements specifications, which basic objectives are to identify and resolve software problems and highrisk issues early in the software life cycle. Verification and Validation activities produce their best results when performed as soon as possible and involve user feedback

Supporting Meta-model-based Language Evolution and Rapid Prototyping with Automated Grammar Optimization

In model-driven engineering, developing a textual domain-specific language (DSL) involves constructing a meta-model, which defines an underlying abstract syntax, and a grammar, which defines the concrete syntax for the DSL. Language workbenches such as Xtext allow the grammar to be automatically generated from the meta-model, yet the generated grammar usually needs to be manually optimized to improve its usability. When the meta-model changes during rapid prototyping or language evolution, it can become necessary to re-generate the grammar and optimize it again, causing repeated effort and potential for errors. In this paper, we present GrammarOptimizer, an approach for optimizing generated grammars in the context of meta-model-based language evolution. To reduce the effort for language engineers during rapid prototyping and language evolution, it offers a catalog of configurable grammar optimization rules. Once configured, these rules can be automatically applied and re-applied after future evolution steps, greatly reducing redundant manual effort. In addition, some of the supported optimizations can globally change the style of concrete syntax elements, further significantly reducing the effort for manual optimizations. The grammar optimization rules were extracted from a comparison of generated and existing, expert-created grammars, based on seven available DSLs.Comment: 34 page