This is the proceeding from the fifth workshop in Order Theory in Environ-mental Science. In this workshop series the concept of Partial Order Theory is development in relation to application and the use is tested based on specific problems. The Partial Order Theory will have a potential use in cases where more than one criterion is included in a prioritisation problem both in relation to decision support and in relation to data-mining and interpretation. Espe-cially the problems where a high degree of complexity results in considerable uncertainty are good candidates for application of Partial Ord