Towards Effective Pipeline Integrity Decision Making Under Uncertain Environment

Pipeline integrity operators often face the challenge of rendering critical decisions even when there is uncertainty in some portion of essential input data. The decision making process can be further complicated by multiple possible courses of integrity action, each of which may contain their own specific uncertainties. This paper presents a multi-attribute decision making process to assist integrity managers in prioritizing and selecting integrity activities necessary for maintaining the safety of their system The proposed approach tackles decisions/actions prioritization process of integrity solutions based on engineering analysis, logistical issues, and availability of the pipeline to deliver the intended capacity; all while maintaining an appropriate safety level. The complexity of some integrity decisions could be better represented through priority versus probability/reliability because there are elements whose contribution or influence is not probabilistic, but nevertheless are describable in terms of priorities. Hence, the proposed approach focuses on two types of uncertainties; uncertainty on available information, and uncertainty about the range of judgments used to express preferences of feasible integrity actions. Integrity actions can take different forms, including excavating a considerable amount of pipeline, applying point or discharge pressure restrictions, executing validation digs, increasing in line inspection frequency, running complimentary in-line inspection technologies, or some combination of these integrity actions. The complexity of optimizing integrity decision arises not only from uncertainties on information, but also from resource availability and feasibility of the various possible integrity actions.