Novel Process Windows (NPW) is an entirely new way of process design to boost micro process technology for the production of high-added value fine chemicals. Such process intensification demands for microstructured reactors with their excellent capabilities on mass and heat transfer and short residence times with prime constructional and functional features. This proposal is truly comprehensive and holistic as it includes four projects with different NPW facets; starting from a molecular-mechanistic- (New Chemical Trans¬formations) and kinetic-scale (High-Temperature / Pressure Processing) via the scale of reaction environment (Solvent-free Operation and Tuneable / Reactive Solvents) up to a process scale (Process Simplification and Integration). These four individual measures are bundled and directed by a generic project for cross-cutting insight, evaluation through cost and life-cycle analysis, and transfer to a large number of reactions. High-p,T processing will enable for the Claisen rearrangement to shrink reaction times by orders of magnitude and to increase space-time yields consequently. Substantial selectivity increases are targeted for this reaction and the hydroformylation. The latter reaction will make use of tuneable solvents and near-critical water processing. As new chemical transformations with process simplification and integration, the direct oxidation of cyclohexene to adipic acid as one-step synthesis and the copper-catalysed triazole Click Chemistry as one-flow multi-step synthesis will be tested. These new and challenging processing technologies provide highly promising perspectives for future ‘green’ chemical factories to boost sustainability, covering the whole manufacturing chain in one system and providing a multi-purpose infrastructure.