C Chart

C hart is seldom made use of to observe the total number of incidents taking place in a given unit of time. The C Chart is a graph which is made use of to learn how a process transforms over time. Information is planned in the order of time. A C Chart at all times have a central line for the average, the upper control limit which is represent by an upper line and the lower control limit is represent by a lower line. These lines are established from past information. By comparing the present information to these lines, you will be able to land upon a decision concerning whether the process deviation is steady or if it is erratic.

C Charts for uneven figures are used in pairs. The chart at the top examines the average or the centering of the distribution of information from the method. The chart in the bottom observes the range or the size of the distribution. If your information be shots hitting the target practice, the average is someplace where the shots are crowded together and the range is how firmly they are crowded. C Charts for characteristic data are made use of one at a time.

Basic Procedure for C Chart:

• Decide the suitable timeframe for gathering and plotting data.
• Gather the data, build your chart and study the figures.
• If there are some out of control signals in the chart, point them out and analyze the cause for error.
• It is always good to document your findings and the methodology that you adopted.

Circumstances under which C Chart can be made use of are as follows:

• When calculating current methods by deducing and correcting problems as they take place.
• When forecasting the predictable range of results from a process.
• When deciding whether a method is steady and is in statistical control.
• When deciding whether your quality development project ought to aimed to avoid specific problems or to make basic modifications to the method.

Questions:

• What is the basic procedure to prepare a C Chart?
• What are the circumstances under which C Chart can be used?