 of the OSI- layers) and important missing parts have been added (primarily a processing plat- form dimension, separated from the layers and the protocols). By integrating the processing system paradigm with the sysnet paradigm, a complete generic model appeared (except for spatial properties). The processing system paradigm can be used to specify the control structure and entities of any process control system in a distribution- and platform-transparent way. It allows the modeller to focus on control aspects only, and to provide detailed specifications of the control structure and of the behaviour of all its functional entities (service objects and abstract machines). The sysnet paradigm can then be applied to that model in order to create the distributed system (or network) view of a processing system and the characteristics of the distributed system (e.g. response times). This view is represented by another set of model types: protocol network, logical net- work and physical network. Together with service network and abstract network, Preface these five model types represent the major separation of concerns in a complete system model. This separation is referred to as the integration hierarchy. This approach to model-based systems engineering had to be thoroughly veri- fied. I therefore spent several years testing and refining the generic model by creat- ing models of both legacy systems and new system concepts in the telecommunication domain. As a spin-off of this endeavor, two additional contribu- tions came forward: a notation and specification language, called Abstract systems Modelling Language, AML, and a method and notation for modelling the resource systems of telecom systems, now also included in AML. The parts of AML that are generally applicable to any type of processing system are well isolated from the parts that specifically aim at describing telecom resource systems. All these paradigms and concepts are described in this book. Since I focus on paradigms and concepts, not on notations, AML is not