Extrusion-based bioprinting is an additive manufacturing technique for the fabrication of biological constructs through layer-by-layer deposition of a bio-ink (viable cells suspended in a biomaterial solution). The planning of a bioprinting procedure involves the definition of several process variables. In extrusion-based bioprinting typical process variables are the printing pressure, nozzle diameter, target extrusion velocity and/or mass flow rate. Moreover, the need to ensure high cell viability at the end of the process is a major critical concern in the bioprinting planning. In fact, the printing mechanisms expose cells to shear and extensional stresses that can lead to damage. Unfortunately, all the afore-introduced process variables are closely interconnected through the rheological response of bio-inks. Non-Newtonian features of bio-inks, as well as non-simple geometries of the extruding system, introduce complex and non-linear relationships between process variables. Hence, the bioprinting planning in laboratory practice is generally made through an expensive and time-consuming trial-and-error procedure. The aim of this work is to develop a novel methodological approach that allows for a fast, effective and feasible set-up of target bioprinting conditions. Coupled influences of fundamental process variables on the extrusion process are modeled via a semi-analytical reduced-order technique, involving a calibration procedure based on few high-fidelity numerical simulations. As a significant outcome, nomograms relating process variables to cell viability are built up. Accordingly, useful indications towards an effective process design tool for bioprinting planning are provided.