The present study investigates a number of key features of microstructured reactors and components devoted to process miniaturization and intensification. For processes involving transfer operations and/or chemical reactions, a simple model can be used to relate the process efficiency to the ratio of two characteristic times: the space time of the process fluid in the system and the characteristic time of the operation. A detailed analysis of the relationship between these characteristic times and the characteristic dimensions of the system highlights the principal operations that should most benefit from the potential of microstructured process components. The analysis is used to examine how microstructured reactors may be advantageously employed to improve process efficiency (intensification) or to reduce process size (miniaturization), as a function of the operations involved.