Hey everyone, welcome to this lecture. What are the characteristics of an out of control process? So far you have known that the process gets out of control when special causes are present. That's when the process becomes unpredictable and unstable. The key question is, how do you recognize whether the process is out of control. There are seven indicators that we will discuss in this lecture that will help you recognize that the process is indeed out of control.

Before we get there, I just have to cover one small topic. A control chart has three zones, Zone A, zone B, and Zone C. These zones are present on each side of the center line. As you can see, Zone C is the closest to the center line. Zone B is the next and so In a is after that, it is safe to say that Zone C is one standard deviation away from the center line. Zone B is two standard deviations away, and Zone A is three standard deviations away. With that background, it is now time to learn those seven indicators that render the process out of control.

Let's begin. The first indicator is where one or more data points fall outside the control limits. This is a no brainer. The data point falls outside of either the upper or lower control limits and the process gets out of control. The second one is when seven consecutive data points have an increasing or decreasing trend. The third indicator is where eight consecutive data points are on one side of the average.

The four is when 14 consecutive data points are alternating up and down. The fifth situation is when two out of three consecutive data points are on the same side of the average in Zone A or beyond. The sixth situation is when four out of five consecutive data points are on the same side of the average in zone B or beyond. And the seven situation is where 15 consecutive data points are within Zone C. They may be above or below the center line. That brings us to the end of this lecture. In the next lecture, you will learn the difference between leading and lagging indicators