Operations Research (OR) is the discipline of applying advanced analytical techniques to help make better decisions. 

The Essence of the Science of Better Philosophy

The essence of the Science of Better is to produce a large, indeed disproportionate, improvement in your organisations outcomes for as small an amount of effort, risk, time and cost as possible. 

The idea is to find you a solution that is significantly more cost effective and timely than your organisations current situation.

While sometimes suitable, the complexities of many real world systems means we may not always attempt to formulate a model to produce a 'mathematically' optimal solution. 

Finding a mathematically optimal solution (if it's even possible) usually costs more, takes much longer, results in a product that is very hard to understand and often the solutions may not be able to be implemented successfully in the light of real world non-linearity, complexities and soft constraints. 

The ethos behind the Science of Better is instead to focus on significantly better outcomes, and not necessarily expend large amounts of time and resources chasing theoretically optimal conditions.  Start as simply as possible, add complexity when its required and evolve to the fastest and most beneficial solution.  That way you don't get bogged down by biting off something bigger than can be easily chewed.