Lean Principles The word lean, in inventory management, refers to a set of various principles, ideas, concepts, and techniques that show a firm how to make do with fewer resources than it normally would use. Any program that continually seeks ways and means to reduce use of resources can be called a lean initiative. Lean programs also demand that customer wants and needs be the focus of all improvement activities. Also, the people involved in various processes in your firm have to be provided with ample and continuing opportunity to contribute ideas for improvement. It is they, after all, who are familiar with the process and hence are more likely to know what changes can work.