Control Charts
A Roadmap for Using Time-Weighted Control Charts
Selecting the correct type of control chart is vital. And with the wide range of options available, the selection of a chart to suit a particular process and data set can be difficult, especially when using time-weighted control charts.
From Quality Control To Quality Improvement
From Quality Control to Quality Improvement is a case study in applying control charts and experimental design.
Integrating SPC and SQC to Overcome Weakness in Either
SQC and SPC are two powerful tools, which have different goals and requirements for successful application. By using a methodology that combines the strengths of both approaches, it is possible to overcome the individual weaknesses of each one.
Make Valid Control Chart and Subgroup Assumptions
Four real world case studies that display how incorrect assumptions can lead to invalid control charts and improper statistical process control (SPC). Don't make these same control chart and subgrouping mistakes.
Non-normal Data Needs Alternate Control Chart Approach
Some people believe that it is not necessary to transform non-normal data before creating an individuals control chart. The chart, however, is not robust to non-normally distributed data. Therefore, it is important to use an alternate approach.
Recalculating Control Limits
The tedious task of analyzing control charts for validity of the limits can be eliminated and the resulting report can be used as a tool to keep the process of continuous improvement on track.
Should You Use a Mean or Individuals Control Chart?
To plot individual data or to group the data and plot the mean on a control chart, that is the question. This article helps you understand how to make the most of your data.
Specification Limits: Proceed with Caution
A true control strategy should be aligned with the process’ statistically based control limits.
The Impact of Control Strategies on Z Shift Values
When special control strategies are applied to typical process data, the observed relationship between Z(short-term) and Z(long-term) is reproduced, and a relationship to estimate Z(short-term) from Z(long-term, discrete) from defect counts is derived.
When to Recalculate Control Limits
A problem that has often confronted practitioners using control charts is when to consider recomputing the control limits. A simple decision matrix and explanation is included in this article.
Why Control Chart Your Processes?
Control charts help you identify and understand process variation. Learn the major elements and control charts and how to construct a control chart.
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