“Statistical Process Control” is one of the most popular terminology now a days. “Statistical Process Control” is the key for validate analytical & statistical methods to highlight the existence of special causes of variation in end to end processes.
Key causes of variation are called “Assignable causes” and they should be ascertained and eliminated. The common causes of variation, called “Chance causes”, and they should not be ignored but they are managed by identifying long term process improvement. However these variations cannot be eliminated from the data totally.
The concept of statistical process control (SPC) is that each and every measurable phenomenon contents a statistical distribution. Its an observed set of data which is made up of a sample of end effects of unknown chance causes. After everything has been completed by eliminate special causes of variation, a certain amount of variability showing the state of control will always remain with in the data.
“Location, spread, and shape” are three basic concepts of a distribution.
– Location is the value of the distribution, such as mean.
– Spread of the distribution is the amount by which smaller values differ by bigger ones, such as, standard deviation and variance.
– Shape of a distribution refers to the patterns like symmetry. Chart of the distribution could be in bell shaped, rectangular shaped, etc.
After Collecting information about process and filtering with statistical formulas Statistical Analyst or SPC expert take necessary action to ensure that the overall process stays in-control and to allow the product to meet the desired specifications. SPC Expert can recommend ways and means to reduce variations, optimize the process, and perform a reliability test to see if the improvements work.
Statistical process control used for planned collection and effective use of data for studying & measuring causes of variations in quality, either as between processes, procedures, materials, machines, etc., or over periods of time.