Stepwise rigorous development of distributed agile information systems: from UML-diagrams to component-based Petri Nets

The Unified Modelling Language (UML) is nowadays the de-facto standard method for developing Object-Oriented (OO) information systems (IS). UML is endowed with semi-formal graphical diagrams, allowing a multi-view based modelling. Further decisive UML strengths include advanced supporting tools as well as the readiness to extensions through stereotypes and profiles. Nevertheless, for contemporary critical IS where high-degree of reliability, flexibility and distribution are requested, such early semi-formal and multi-viewed UML-based modelling requires to be leveraged towards more disciplined, verifiable and intrinsically distributed specification. That is, first, the rigorous coherence between structural and behavioural diagrams have to be addressed. Secondly, the formal validation/certification of the application crucial properties should be soundly handled. Thirdly, the targeted UML-driven unified framework has to cater for componentisation, true-concurrency and adaptability. With the aim to preserve all the above UML strengths, we propose to describe early IS requirements using tailored UML diagrams, with mainly class-diagrams, OCL constraints and state-charts. We then smoothly shift these intuitive UML-driven IS multi-views towards a more unified, rigorous and distributed conceptual modelling, where certification and validation are intrinsic. This phase is governed by a rigorous component-based operational and visual framework called CO-NETS. It is based on a formal integration of most OO concepts and mechanisms, enhanced with modularity principles, into a variant of high-level Petri Nets. For rapid-prototyping purposes, CO-NETS behaviour is governed by Meseguer's rewriting logic. This innovative UML-CO-NETS-driven proposal for IS model-driven development is a validated, through a non-trivial case-study, on production systems.