rCOS stands for refinement of object and component systems. It is a formal method providing component-based model-driven software development.
rCOS was originally developed by He Jifeng, Zhiming Liu and Xiaoshan Li at UNU-IIST in Macau, and consists of a unified multi-view modeling notation with a theory of relational semantic and graph-based operational semantics, a refinement calculus and tool support for model construction, model analysis and verification, and model transformations. Model transformations automate refinement rules and design patterns and generate conditions as proof obligations. rCOS support multiple dimensional modeling: models at different levels of abstraction related by refinement relations, hierarchy of compositions of components, and models of different views of the system (interaction protocols of components, reactive behaviors of components, data functionality, and class structures and data types). Components are composed and integrated based on their models of interfaces to support third party composition.[1]
