Quantity Analysis in Control Chart Processes

Running head: QUANTITY ANALYSIS
Quantity Analysis in Control Chart Processes
Name
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QUANTITY ANALYSIS 2
Introduction
A control chart is a time that indicates the changes experienced in a process over time. It
is thus drawn against the time series. The graph majorly consists of three parts i.e. the upper line
which indicates the upper control limits of the graph, the middle line for the average and the
lower line for the lower limits The sole function of a control chart is to monitor any variations at
a particular time in the process. A pattern being out of control means that the variations in the
process do not occur as per the expectations. This happens when the points selected surpass the
lower limit or the upper limit. The patterns indicating the process is out of control are discussed
below
If a special cause in the process occurs, the alarm condition is not signaled immediately.
The cause is then determined by taking the summations of the variations and average of the
process in question. The quantification of these changes is what is used to find the out of control
average run length for the control chart. The average run length (ARL) refers to the observations
quantification of observations that a certain process is out of controls before any variations occur
When there is one point that is outside the control limits. This occurs when one particular
point in the control chart is above the specific upperlimits. A control chart is composed of the
three parts i.e. the ULC, LCL and the average (Qiu, 2017). Aviolation of an upper-class limit is a
signal to show an out of control process.The control charts are operational on the basis of time
series where it is based on historical information. New and primary data is usually collected with
more time allocation to a particular process. Thus a point out of the limits such as upper-class
limits indicates out of control process.
When two points of the three points are plotted on the same section of the centerline and
farther than 2 deviations from it then the point i.e. sends a signal of out of control process.