International Journal of Software Engineering and Its Applications Vol. 7, No. 1, January, 2013 107 A Formal Semantic for Scenario-Based Model Using Algebraic Semantics Framework for MOF M. A. Isa, Dayang N. A. Jawawi and M. Zulkifli M. Zaki Department of Software Engineering Faculty of Computer Science and Information System Universiti Teknologi Malaysia (UTM),Skudai 81300, Johor Bahru, Malaysia {mohdadham, dayang, zulkiflizaki}@utm.my Abstract Model-driven development uses models to represent system artifacts to improve the visibility of the system towards the real world. The development of models is underlying in the meta-object facility (MOF) standard in order to define the building concepts of metamodel and models. However, these concepts, especially within MOF standard, are not yet formally define which will be difficult to check the consistency between metamodel and models. Therefore, defining a formal semantic for MOF-based metamodel is essential for discovering the meaning of the model and to ensure a structural and behavioral conformance between metamodel and its model. In this paper, we define a formal semantic for a scenario-based model called Performability Failure Behavior Awareness Metamodel (PerFAM) by applying algebraic semantics for MOF framework which provides a formal stage: metamodel, model and model conformance. For this purpose, a formal consistency checking can be applied as to ensure the accuracy of the produced model towards its metamodel. Keywords: MOF, Metamodelling Semantics, formal analysis, metamodel 1. Introduction Modeling a system is important to be able to represent the abstract level of the system from a real world aspect. The process of modeling the software system can be realized through model-driven development in which system artifacts are represented as models in order to enhance visibility, understanding and quality. Presently, models are first class artifacts in a modeling domain where models are capable of providing a rigorous understanding of the system on a more abstract level [1]. The meta-object facility (MOF) [2] provides a systematic framework to define a new modeling language in which the abstract syntax can be declared in a specific domain concept. Hence, the MOF also provides a basis for better model-driven development in terms of model and metamodel definition, as well as defining the conformance between models and metamodels. However, the MOF framework does not provide a standard notion for formally defining the metamodel semantics in a systematic way [3]. This shortcoming then produces a few problems in a model-driven development process. The metamodel is a collection of data based on MOF framework. This data builds up the modeling languages that will be used to produce a set model that conforms to that metamodel. However, when the metamodel is not formally defined in the syntax and semantic definition, problems such as misinterpretation of models among developers cannot be avoided [4]. This problem could cause some metamodel derivation problems when interpreting from a metamodel to its model. Therefore, it is important to have a formal semantic for metamodel and models so as to ensure the consistency for models production from its metamodel and the correctness of system design.