Cornerstone Introduction
Cornerstone Design of Experiments
Cornerstone Principal Components
Cornerstone Extension Language
Cornerstone Control Charts
Cornerstone Multiple Regression
Cornerstone Manova
Cornerstone Distribution Fitting and Process Capability

 

Characterize Your Process

Distribution fitting analysis helps you model how your process output varies. Having this understanding can help you to characterize a process and hence make informed predictions. Process capability analysis helps you determine how capable a process is of consistently producing output that satisfies engineering or customer specifications.

Ideally, your process would produce output within specifications with perfect consistency. Every process, however, has inherent limitations on the level of quality and the consistency of its output. With Cornerstone’s Distribution Fitting & Process Capability analysis module you can quickly evaluate your current process and interactively explore its behavior.

Seamless Data Analysis Environment

Distribution fitting is the first step in understanding the variability in your data. You can use Cornerstone to fit normal, lognormal, exponential or Weibull distributions and have Cornerstone select the “best fit” for you automatically.

You may fit distributions to a histogram or plot your data using distribution probability plots. Cornerstone provides interpretations to help you find the distribution that best matches your data.

Process capability analysis extends distribution fitting to allow you to specify a target value and/or upper or lower specification limits. Cornerstone uses these limits and the “best fit” distribution to predict how well the process will stay within specifications.

You can investigate a process using Cornerstone’s interactive data exploration tools. If you select a subset of data, or exclude data points, Cornerstone recalculates distributions and capability indices and updates all graphs and tables automatically.

Exploratory and Interactive Data Analysis

If you are interested in exploring the effect of varying engineering specifications on acceptable process output, you can drag the specification reference lines. Cornerstone immediately recalculates capability indices and updates the graph and summary tables.

Extend Your Application

Distribution Fitting & Process Capability’s functionality is part of a suite of data analysis modules. The functionality in all of Cornerstone’s analysis modules is accessible through the Cornerstone Extension Language (CEL). CEL allows you to extend Cornerstone and to create custom, site-specific applications.

Features

Distribution Fittings Analysis

· Interactively fit a distribution to a histogram
· Normal, lognormal, exponential and Weibull distributions
· “Best fit” option based on Chi-square statistics
· Distribution statistics summary (count, mean, std. dev., min., Q1, median, Q3, max., IQR, Skewness, Kurtosis, threshold, scale, shape, Chi-square, d.f., p-value)
· Bin distribution summary shows precise bin count for data, and predicted bin count for each fitted distribution

Process Capability Analysis

· User-selectable statistics and indices
· Capability indices table (percent > USL, percent < LSL, percent in spec., Cp, Cpl, Cpu, Cpk, Cpm, CR, k)

Interactive Graphics

· Brushing, subsets and data labeling
· Ability to change specification limits by dragging them in a graph
· Ability to annotate graphs