In the past four decades, new approaches and methodologies have been developed to solve unstructured and messy problems with various stakeholders. Among these methods, soft system methodologies, cognitive mapping, and strategic choice approach are specifically worthy to be heeded. The methods mentioned above, which have a precise structure and clear framework, are often categorized as soft operations research or problem structuring methods. Today, there is ample literature on soft research and it is taught in many operations research/management science courses of reputable universities. Methods of research on soft OR are rooted in soft system thinking and belong to the interpretative/learning paradigm. Nonetheless, assigning a clear and precise boundary between hard and soft OR techniques is not easily feasible, for most of these techniques– based on their application in different situations – can be classified as both hard and soft. The aim of this research is to investigate the origins and current position of soft methodology of operations research and probe into its theoretical basis. A comparison between the trend of OR in the US and UK clearly demonstrates the differences in soft and hard approaches. Generally, it can be concluded that soft and hard approaches of OR are complementary: soft methods are exploited in forming the structure (configuration) of a problem and hard methods are utilized in solving it.