np-chart: When is it used?

Use np-charts when you can answer yes to these questions:

1. Do you need to assess system stability?

2. Is the data the number of nonconforming items per subgroup?

3. Are the subgroups the same size?

4. Are there only two outcomes to any given check?

5. Is the time order of subgroups preserved?

See also:
>np-chart: What is it?
>np-chart: What does it look like?
>np-chart: Getting the most