AbstractPipelines are the most common and economical way of transporting hazardous liquid hydrocarbons. Steel pipelines suffer different degradation mechanisms due, in part, to corrosion reactions. Failure in a hazardous liquid pipeline can result in catastrophic environmental damage as well as societal health and safety threats. There are many standard methods for performing consequence analysis of oil, gas, and petrochemical piping systems, but there is no standard procedure for calculating the consequence of a failure of a transmission pipeline. Lacking accurate formulations, the majority of pipeline consequence analysis is performed employing qualitative assessment techniques. The qualitative methods are highly dependent on the proficiency and experience of the assessment team, and suffer a lack of repeatability and reliability of the results. This study improved the efficiency of the consequence analysis during qualitative risk-based inspection analysis of liquid pipelines by utilizing gray theory. The input parameters for a practical analysis include the most essential design, operation, and commissioning parameters, which can be captured easily from project documents. The suggested gray method for consequence analysis of the pipeline minimizes the participation of the appraiser in the decision-making process, reduces variability of the analysis by reducing human error, and thus increases the reproducibility and accuracy of the results.