Variation!
Though sometimes we may refuse to recognize it, the world is a full of variation, even in the things we think or believe are constant. For example, my wife has been known to say, “you always do…” or “you never do…”, to which I retort, I am human and I am not that repeatable. I say that, but it is not just humans that are not so repeatable. Everything has variation, and understanding this variation, is important for product development, project management, manufacturing, product testing and so much more. To master this work, we need to understand this variation as completely as possible.
Common and Special Cause Variation
Shewart is credited for developing the concepts of special and common cause [1]. Special cause variation, are variations that are outside of the expected (intermittent) range of possibilities. Common cause variation, are the variation expected, we know about these, these are predictable, provided we have put some effort into learning about … Continue reading