In mathematical terms, data can be termed as “facts and statistics collected together for reference or analysis”.
In philosophical terms, data can be said to be “the things known or assumed as facts, making the basis of reasoning or calculation”.
The mistakes while interpreting data are mainly of two kinds. They are:
Mistake 1: To react to an outcome as if it came from a special cause (signal), when actually it comes from the common cause variation (noise).
- In simple words it can be rephrased as: Interpreting noise as if it were a signal.
Mistake 2: To treat an outcome …show more content…
making broader conclusions based on limited information, for example, on a small set of data or results), casually sampling (undersampling – removing common cases from the analysis and oversampling – duplicating rare/odd cases), etc.
Edwards Deming in his book THE NEW ECONOMICS says “Unfortunately, it is impossible to reduce both mistakes to zero. Dr. Shewhart’s contribution was to conclude that the best we can do is to make Mistake 1 now and then, and Mistake 2 now and then, both preferable rarely, following the rules that will over the long run minimize the net economic loss from both mistakes.”
The Shewhart cycle or Shewhart learning and improvement cycle combines management thinking with statistical analysis. The constant evaluation of management policy and procedures leads to continuous improvement. The Plan–Do–Check–Act (PDCA) cycle, or the Plan–Do–Study–Act (PDSA) cycle. While Deming marketed the cycle to the masses—a cycle which he called the Shewhart cycle—most people referred to it as the Deming cycle.
The Shewhart cycle has the following four …show more content…
By keeping the process in control, it would be possible to predict future output and to economically manage processes. This was the birth of the modern scientific study of process control.
Shewhart believed that statistical theory should serve the needs of industry and society as a whole. He challenged the norms of his day and showed manufacturers the better way that revolutionized industry.
He preached the importance of adapting management processes to create profitable situations for both businesses and consumers, promoting the utilization of his own creation -- the SPC control chart.
Dr. Shewhart believed that lack of information greatly hampered the efforts of control and management processes in a production environment. In order to aid a manager in making scientific, efficient, economical decisions, he developed Statistical Process Control methods. Many of the modern ideas regarding quality owe their inspirtation to Dr.