An improved translation of SA/RT specification model to high-level timed Petri nets

The article proposes an approach for defining extensible and flexible formal interpreters for diagram notations with significant dynamic semantics. More precisely, it addresses semi-formal diagram notations that have precisely-defined syntax, but informally defined (dynamic) semantics. These notations are often flexible to fit the different needs and expectations of users. Flexibility comes from the incompleteness or informality of the original definition and results in different interpretations.The approach defines interpreters by means of a mapping onto a semantic domain. Two sets of rules define the correspondences between the elements of the diagram notation and those of the semantic domain, and between events and states of the semantic domain and visual annotations on the elements of the diagram notation. Flexibility also leads to notation families, that is, sets of notations that share core concepts, but present slightly different interpretations. Existing approaches usually interpret these notations in isolation; the approach presented in this article allows the interpretation of a family as a whole. The feasibility of the approach is demonstrated through a prototype generator that allows users to implement special-purpose interpreters by defining relatively small sets of rules.

Section: Related Workmentioning

confidence: 99%

Formal interpreters for diagram notations

Baresi

Pezzè

2005

“…The practical tools, automating the formalization by a translation, involve taking care in building formal models following structured methods, where composition of models of parts of a specification is handled well, and complexity of the resulting models (in terms of, for example, state space size) is limited. For example, formalizations of SA/RT feature the one of Shi and Nixon [1996] in terms of timed Petri nets. It proposes an automated translation with compositionality and complexity improved with respect to earlier models.…”

Section: Related Workmentioning

confidence: 99%

Modeling statecharts and activitycharts as signal equations

Beauvais

Rutten²,

Gautier

et al. 2001

The languages for modeling reactive systems are of different styles, like the imperative, state-based ones and the declarative, data-flow ones. They are adapted to different application domains. This paper, through the example of the languages Statecharts and Signal, shows a way to give a model of an imperative specification (Statecharts) in a declarative, equational one (Signal). This model constitutes a formal model of the Statemate semantics of Statecharts, upon which formal analysis techniques can be applied. Being a transformation from an imperative to a declarative structure, it involves the definition of generic models for the explicit management of state (in the case of control as well as of data). In order to obtain a structural construction of the model, a hierarchical and modular organization is proposed, including proper management and propagation of control along the hierarchy. The results presented here cover the essential features of Statecharts as well as of another language of Statemate: Activitycharts. As a translation, it makes multiformalism specification possible, and provides support for the integrated operation of the languages. The motivation lies also in the perspective of gaining access to the various formal analysis and implementation tools of the synchronous technology, using the DCϩ exchange format, as in the Sacres programming environment.

“…Petri nets corresponding to Ward's transformation schemas are also built by some commercial tools, e.g., DESIGN/IDEF [Meta Software 1992] or precommercial prototypes, e.g., IPTES [Bologna 1993]. Petri nets are used in Richter and Maffeo [1993]; and Shi and Nixon [1996] to ascribe semantics to ESML [Bruyn et al 1988], and in France and Wu [1995] to ascribe semantics to the Hatley and Pirbhai's requirements definition notation [Hatley and Pirbhai 1988].…”

Section: Introductionmentioning

confidence: 99%

Toward formalizing structured analysis

Baresi

Pezzè

1998

Real-time extensions to structured analysis (SA/RT) are popular in industrial practice. Despite the large industrial experience and the attempts to formalize the various "dialects," SA/RT notations are still imprecise and ambiguous. This article tries to identify the semantic problems of the requirements definition notation defined by Hatley and Pirbhai, one of the popular SA/RT "dialects," and discusses possible solutions. As opposed to other articles that give their own interpretation, this article does not propose a specific semantics for the notation. This article identifies imprecisions, i.e., missing or partial information about features of the notation; it discusses ambiguities, i.e., elements of the definition that allow at least two different ("reasonable") interpretations of features of the notation; and it lists extensions, i.e., features not belonging to the notation, but required by many industrial users and often supported by CASE tools. This article contributes by clarifying whether specific interpretations can be given unique semantics or retain ambiguities of the original definition. The article allows for the evaluation of formal definitions by indicating alternatives and consequences of the specific choices.