SPC Charts: The benefits and types of control charts used in quality improvement initiatives
SPC charts are used for tracking and monitoring data from business processes in various type of organizations. The SPC charts were originally developed and used for quality control management of processes mainly in production, manufacturing and industrial companies.
However since the beginning of the use of process analysis and widely recognizing and understating the business processes in service industries and other organizations, the application of SPC charts has increased in many other industries as well. Today, SPC is continuously used for quality improvement and applied to banks, healthcare organizations, logistics companies, and literally all kinds of companies from small businesses to large corporate operations.
The benefits of SPC charts are recognized by many companies because they allow quality professionals and business managers to understand, analyze and improve their processes by using control charts which identify if processes are in control and recognize immediately if something is going wrong in the process. Effective process analysis can save companies a lot of money by minimizing process errors and product defects and as a result drastically improving customer satisfaction.
At a very basic level, control charts (regardless of the type of control chart used) show the trends of the process data, the lower control limit and the upper control limit of the process so users can easily recognize any unacceptable variations. These lines on the charts allow users to easily look at the range, variation and the tendency of the process data. The upper and lower control limits are used by managers to see if the variations are significant and unacceptable or they are within an acceptable normal level. One of the main benefit of using control charts is the ability to differentiate between random variation (which is normally find in every process) and non-random behavior which is critical even when it is identified within the control limits.
The use of control charts generally starts with developing the initial control chart for testing and analysis of the process in terms of whether there is a statistical control. Next, the causes of non-random variations are identified and fixed and the control limits are recalculated. Now the process analysis continues by looking for and identifying additional non-random variations and their causes. This approach can be used as many times as it is required until the process reaches an acceptable statistical control.
Depending on the process, the time required for this initial approach to continuous quality improvement can be different – for complex processes it might take a long time however this is the starting point of any quality improvement initiative and must be completed successfully. Once your process in in statistical control, your job is to continuously monitor and control the process.
Download Automated SPC Control Charts for Excel Users:
The most frequently used types of control charts include: X bar & R Chart, X bar & Chart, Individual / Moving Chart, c Chart, u Chart, p Chart and np Chart.