Tools

Concepts

Control Chart Properties

Rational Subgroups

Defining Control Limits

Short Run Techniques

Interpretation & Calculations

Attributes Charts

X-Bar / Range Charts

X-Bar / Sigma Charts

Individual-X Charts

Moving Average Charts

Multivariate Control Charts

Histograms, Process Capability

Autocorrelation Charts

Measurement Systems Analysis

Applications

Getting Started with SPC

Key Success Factors for the Implementation of SPC

How to Study Process Capability

Multiple Steam Processes

Analysis of Batch Processes

SPC to Improve Quality, Reduce Cost

Struggling with Independence

SPC Analysis of MLB Home Runs

Use Of SPC To Detect Process Manipulation

Using Data Mining and Knowledge Discovery With SPC

Np Chart Calculations

Plotted statistic for the Np Attribute Control Chart

the number of items in a sample meeting a criteria of interest

Center Line

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where m is the number of groups included in the analysis.

UCL , LCL (Upper and Lower Control Limit)

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where n is the sample size, np-bar is the Average count , and p-bar is calculated with the following Np chart formula:

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The Np chart formula are easily calculated for you using our SPC software.

See also:

When to Use an Attribute Np Chart/a>

Interpreting an Attribute Np Chart

Learn more about the SPC principles and tools for process improvement in Statistical Process Control Demystified (2011, McGraw-Hill) by Paul Keller, in his online SPC Concepts short course (only $39), or his online SPC certification course ($350) or online Green Belt certification course ($499).