Complex systems are usually made of heterogeneous components, either hardware or software or both. Component interactions, mostly those unexpected, are a source of conflict, since one of the main concerns for system reliability and predictability is precisely this component interaction. This paper reviews a number of approaches, produced over an eight year period, to component interaction focussing on component interaction modelling, testing and testing coverage. Other topics such as component interaction observation and pure monitoring/visualization of component interactions are outlined
