Occam's razor is an early statement of the parsimony principle, which was given by William of Occam (1280-1349) namely 'entia non sunt multiplicanda praeter necessitatem'; which means 'A plurality should not be posited without any necessity'. In other words we can say that one should not make more assumptions than the minimum required. The concept underlies all the scientific modelling and theory building, and helps to remove those variables and constructs which are not really required to explain the particular occurrence, with the consequence that there is less chance of introducing the inconsistencies, ambiguities and redundancies.