Learn about NP charts

What is an NP chart?

An NP-chart is an attributes control chart, which collects data from the subgroups of the same size. NP-charts helps you understand how the process changes over a period of time, the process is measured by the total number of nonconforming items it produces. The process attribute is always described in a yes/no form. NP-charts are used to determine if the process is stable and predictable, and also allows you to see the effect of implementing new strategies. When you monitor the whole process you are guaranteed to get better results for the process. If you find that you are not going as you have predicted then you can implement new ways and also keep a track of the process through NP – Charts to see if the process is stable or not.

What do you need NP Chart?

Following are the scenarios when you will need to use the functions of the NP chart.

• When you to check the stability of the process involved
• The data is collected from the subgroup of same size.
• There are only two outcomes of the given process.
• When the time order of subgroups preserved

How is NP chart different from P chart?

They are practically the same thing, the difference lies in the size of the subgroup, in case of the NP chart you will be using same size sub group while in case of P chart it will vary. Also P shows the fraction of defective while in case of NP chart you will find the number of defective. 

Giving good quality output is one of the most important aspects of any production process, so it is necessary that proper care is taken. The NP chart allows you to take care of the production process by monitoring you production, it also sees to that your production process is stable and predictable, thereby making your organization run in a smooth manner. If you have implement new strategies in your production, then the NP chart will also help you in better understanding the output of these new strategies.