Abstract :
[en] Today, numerous organisations rely on information software systems to run their businesses. The effectiveness of the information software system then, depends largely on the degree to which the organisation's business is accurately captured in the business model. The business model is an abstract description of the way an organisation's functions. Thus, the more precise the business model, the more accurate the requirement definition of the information software system to be engineered.There are an abundance of tools and notations available today to support the development of many types of business process. Many of these artifacts rely on the concept of a business process to describe a business model. A business process is commonly known as a set of one or more linked procedures or activities which collectively realise a business objective or policy goal, normally within the context of an organisational structure defining functional roles and relationships". This thesis is concerned with modelling business processes as a means to accurately capture an organisation's activities and thus, the requirements of the software system that supports these activities.Among the infinite set of possible business processes, this thesis targets only those characterized by the qualities of dependability, collaboration and time. Business processes having these specific dimensions are referred to as Dependable, Collaborative and Time-Constrained (DCTC) business processes. A dependable business process is one whose failures or the number of occurrences in which business process misses its goal are not unacceptably frequent or severe (from certain viewpoint). A collaborative business process is one that requires the interaction of multiple participants to attain its goal. A time-constrained business process is one that owns at least one property expressed in terms of an upper or lower time bound. This thesis investigates how DCTC business processes can be described such that the resulting model captures all the relevant aspects of each dimension of interest. In addition, the business model must be comprehensible to the stakeholders involved not only in its definition, but also in its further use throughout the software development life cycle.A revision and analysis of notations that exist for modelling business processes conducted in this thesis have revealed that today there does not exist any modelling language that provides comprehensible, suitable and sufficiently expressive support for the characteristics of dependability, collaboration and time in an integrated manner. Hence, a significant part of this thesis is devoted to the definition of a new business process modelling language named DT4BP. The aim of this new modelling language is to be comprehensible, suitable and expressive enough to describe DCTC business processes. The definition of this new modelling language implies that a concrete syntax, an abstract syntax, a semantic domain and a semantic mapping is provided. The definition of this new modelling language is given following the Model-Driven Engineering (MDE) approach, and in particular the metamodelling principles. Thus, meta-models and model transformations are used to precisely specify the abstract syntax and semantic mapping elements of the language definition, respectively. Since DT4BP is a textual modelling language, its concrete syntax is specified by a context-free grammar. The Coordinated Atomic Actions conceptual framework with real-time extensions (Timed-CaaFWrk) is used as the semantic domain as it covers a large part of the abstractions included in dependable collaborative time-constrained business processes. The formalisation of this semantic domain according to the metamodelling principles is also part of the material presented in this thesis. Since the business model is considered as a representation of the requirement document the software system to be developed, it is crucial to validate whether it captures the requirements as intended by the stakeholder before going further in the software development process. Hence, besides the comprehensibility, suitability and expressiveness of the modelling language with respect to the domain of interest, it is of special interest to provide a mechanism that allows modellers to ensure that the business model is correct with respect to the stakeholder's expectations. One way of achieving this goal is to provide the modelling language with an executable semantics. In this manner, any business model can be executed on sample input data, and its dynamic behaviour observed. The observation of the dynamic behaviour of the model may be considered as a simulation of the model based on the sample input data. By performing several simulations of the model, the modeller, in cooperation with the stakeholder, can judge whether the business model is correct. This thesis provides an executable semantics for Timed-CaaFWrk that, used in combination with the model transformation that defines the semantic mapping element of the language definition, allows DT4BP models to be validated by simulation. In this manner, the dynamic behaviour of a particular DT4BP model for a given sample input data can be observed by transforming it into a Timed-CaaFWrk model, which is then run thanks to the given executable semantics.
