Settanni, E., Heijungs, R. and Srai, J.S. (2023). Where have all the equations gone? A unified view on semi-quantitative problem structuring and modelling The Journal of the Operational Research Society, 74(1):290--309.

For several decades structural modelling has assisted decision makers with the cognitive burden of exploring and interpreting complex situations. Three well-known techniques – labelled collectively here as semi-quantitative problem structuring and modelling (SPSM) – include ISM (Interpretive Structural Modelling); MICMAC (Matrice d{\textquoteright}Impacts Croisés-Multiplication Appliquée à un Classement); and DEMATEL (DEcision MAking Trial and Evaluation Laboratory). SPSM approaches pioneered the joint application of graph-theoretical principles and human-computer interaction. Yet today a template-style research approach prevails, focusing on the application context rather than seeking to advance or critically assess the individual techniques in their own right. This paper develops a unifying methodological view of SPSM, currently missing in the literature, by comparing and contrasting – for each technique – analytical and procedural aspects typically taken for granted. The paper{\textquoteright}s findings highlight: (1) Previously unnoticed overlaps between techniques that up to now have been deemed mutually exclusive, and incongruences between those that are often applied jointly; 2) Potential issues that arise when key analytical principles of SPSM are either applied uncritically or dispensed with altogether; 3) The need to leverage human-computer interaction, a prominent aspect in early SPSM research that is now surprisingly neglected. These findings are illustrated by a review of SPSM applications in the context of supply chain risk management.