Fires following road or railway accidents may escalate and cause catastrophic loss of containment and extremely severe final scenarios when hazardous material tankers are engulfed in flames. A heat-resistant coating is usually adopted to protect such tankers. However, defects may form on the coating due to wear, erosion, or accidental failures, thereby affecting the effectiveness of the thermal protection. In the present study, a methodology was developed to assess the performance of thermal protection coatings in the presence of defects. A thermal model based on finite element modeling (FEM) was developed to reproduce the behavior of tankers coated with defective insulation when exposed to fires. Experimental data were used to validate the model, which allowed to determine the temperature profile of tank shell with respect to time under different fire conditions. Specific key performance indicators (KPIs), calculated on the basis of the results of FEM simulations, were defined. The KPIs allow the identification of threshold conditions in which fireproofing performance is degraded and jeopardizes the structural integrity of the protected vessel when involved in fire. An approach based on the KPIs was developed to support the implementation of on-condition inspection-based maintenance strategies of thermal coatings. (C) 2016 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.