Diversity, deviation, and variation are three words we commonly used. Most people would think they are synonymous. They are not. Of the three words, one word brings fear to the manufacturing and service industries. Which word when apply to your processes causes the biggest headache? Look at the following three diagrams and pick your choice. To the readers from engineering discipline, the choice is obvious, others might need a shift in paradigm.

There is nothing to fear about diversity (sex, race, religion, language, nationality, etc.) within a company if everybody is aligned towards a common vision, objectives, and mission.(Diagram 1)

Deviation is a misalignment in peoples' thoughts and actions towards a common goal and this can be corrected. There is an offset in direction and corrective actions can be made to shift it back on track.(Diagram 2) Our most feared word is variation. Many are not on heading towards the same direction. They move in all directions and in whatever patterns they like except the intended way.

Variation is our biggest headache!(Diagram 3) The ultimate purpose of Six Sigma from the technical perspective is to design and control all mission-critical processes on target and reduce their variation.