The UML as a Formal Modeling Notation

Abstract

The Unified Modeling Language (UML) is rapidly emerging as a de-facto standard for modelling OO systems. Given this role, it is imperative that the UML have a welldefined, fully explored semantics. Such semantics is required in order to ensure that UML concepts are precisely stated and defined. In this paper we describe and motivate an approach to formalizing UML in which formal specification techniques are used to gain insight into the semantics of UML notations and diagrams. We present work carried out by the Precise UML (PUML) group on the development of a precise semantic model for UML class diagrams. The semantic model is used as the basis for a set of diagrammatical transformation rules, which enable formal deductions to be made about UML class diagrams. It is also shown how these rules can be used to verify whether one class diagram is a valid refinement (design) of another. Because these rules are presented at the diagrammatical level, it will be argued that UML can be successfully used as a formal modelling tool without the notational complexities that are commonly found in formal specification techniques.

An ASM Semantics of UML Derived from the Meta-model and Incorporating Actions

“…This work is followed by more elaborated formalization efforts. The most notable of them are those done by the pUML group [7,8], oriented towards formalizing UML in Z.…”

“…The need for a precise semantics of UML was often stated [7,8]. A sound semantics for UML allows to build tools that check models, simulate them, and generate code.…”

Developing BON as an Industrial-Strength Formal Method

“…It has recently been combined with the Object Constraint Language (OCL), to provide better support for formal modeling and design by contract. The Precise UML group has studied formalizing parts of the notation [4]. In terms of the criteria discussed in Section 2, UML (including the OCL) satisfies most of the criteria: restrictability, gradual introduction, tool support, and modularity are clearly satisfied, although tools for supporting the UML and OCL are needed.…”

“…Some researchers are also looking to UML as a basis for the application of formal methods in software development [4]. A less known approach is the Business Object Notation (BON) [21].…”

Bases for the development of LAST: a formal method for business software requirements specification

“…This approach has been applied to a variety of structured methods, using various formal notations [17]. Recently, research has focused on the formalization of UML syntax and semantics [12]. ² The alternative is to treat the formal and various structured models as overlapping views, none of which is a complete representation of the system.…”