Professor Brian Scarlett initiated and promoted the 4M business for particle technology for many years. The four M's consist of making, measuring, modeling, and manipulating. Measuring and modeling are tools to design and control products and processes, which one wants to make and manipulate. In order to properly utilize the 4M business, a systems approach needs to be used in which every system has its own time and length scale. In this paper, the 4M business and systems approach as taught by Professor Scarlett are explained and their applicability to powder flow is discussed. It is shown that the four M's are largely interconnected and are more useful when used in conjunction with one another.