Atom transfer radical polymerization (ATRP) is one of the most powerful techniques for the synthesis of well-defined polymeric materials. In contrast to free radical polymerization, the major industrial production technique, ATRP allows synthesis of polymeric materials with predetermined molar mass, polydispersity, functionality, composition and microstructure and has led to an explosive development of new functional polymeric materials with applications as surfactants, thermoplasts, coatings, elastomers, drug delivery systems etc. The control over the polymer properties results from a subtle balance between the rates of all chemical reactions involved. Even though several industrially appealing ATRP techniques have been developed, their commercial use has been hampered due to the lack of quantitative insight into the various factors that govern the subtle balance between the reaction rates. The aim of this research project is to develop and validate a versatile tool for the kinetic modeling of (co)polymerizations by various atom transfer radical polymerization (ATRP) initiation techniques. Coupling with available reactor models, that describe mixing phenonema at reactor scale, enables evaluation of the performance of these ATRP techniques at industrial scale.