SPC Guide
First Word


Quality Software
Software Reviews

by PQ Systems Inc.

System Requirements: 386 or better PC; Windows 3.1, 3.11, 95 or NT; 16 MB RAM; 12 MB free disk space.

Price: $595 for the first license, $495 for each additional license.

Contact: PQ Systems Inc.
10468 Miamisburg-Springboro Road
Miamisburg, OH 45342
Telephone: (800) 777-3020
Fax: (937) 885-2252

No-Fear SPC
SQCpack 3.0

by Dirk Dusharme

Inexpensive computers and even less expensive software have enabled even the most statistics-phobic shop floor manager or machine operator to fearlessly utilize statistical process control (SPC). One such software program is the easy-to-use SQCpack for Windows by PQ Systems. This Microsoft Access-based program provides all the usual SPC tools at the click of a button.

 Users select the type of data they want to input (variables or attributes) or the type of analysis they want to perform (control charts, histograms, Pareto or capability) by clicking on the appropriate icons on the start-up screens. For users more familiar with the software, SQCpack provides one of the nicest user-interface screens we've seen. It allows users to select whether to work on charts or data; whether the chart or data is for a variables, attributes, Pareto or Multi-charts; and the group of data or characteristic that they want to use, all from one screen. Navigating from group to characteristic to data to chart doesn't get much easier.

 Users create groups of data (all measurements related to a specific process) by entering the group name; the characteristics to be monitored (e.g., length, width, height); limits, target values and subgroup sizes for those characteristics; procedures; and assignable cause lists, in the group edit or characteristic edit screen. For each group, users may also define up to 20 identifiers. These might include such IDs as date, time, operator, location or batch.

 Once a group and its characteristics are set up, data may be imported or manually entered into a spreadsheet-like screen. Manual data entry is straightforward. For each measurement, group ID data such as date and time can be auto-entered by SQCpack, or the user can choose an entry from a user-defined drop-down menu--useful for operator names. Users may create extensive notes or assignable causes for any data point.

 During data entry, we were confused by the lack of column labels. Column labels aren't shown until the cursor is in that column, so you have to scroll through the columns to find the column you want. PQ Systems is examining other methods for handling column labels in an upcoming release.

 Attributes data is easily handled, including varying subgroup size. SQCpack automatically selects which chart--p, np, c or u--will be drawn based on whether the subgroup size is fixed or variable and whether you are measuring defects or defective units.

 Pareto data is also easily handled and users can choose to display count data, cost data or both. Displaying both charts is useful when prioritizing quality improvement projects.

 Once data is input, all that's left is to draw the charts. Users select default charts or define their own using a chart setup screen. For variables data, the setup screen includes all the familiar SPC charts: individual, moving range, moving sigma, moving average and run charts. Users may modify chart titles and axis labels and either use the software's calculated limits or create their own.

 To chart data, simply select the data, select the chart and click "Draw." Charted data can exclude data points with assignable causes. SQCpack charts work best with small to medium amounts of data on a 600 x 800 pixel monitor. The software fits the chart into the existing screen size. There is no zoom or scroll. If you have a lot of data (more than 150 points or so), the data points begin to resemble a line rather than discrete points. This makes it difficult to use what is otherwise a nice SQCpack feature--the ability to click on a graph point and read the actual data. Depending on how you use chart data, this may or may not be a problem. PQ Systems says that the next release of SQCpack will deal with this issue.

 The program also produces histograms and performs capability analysis on normal and non-normal data distributions. Non-normal data is handled automatically by fitting a Pearson curve to the distribution before doing the analysis.

 For the SPC novice, SQCpack has an excellent online SPC primer, "Quality Advisor," that helps you pick the best SPC tools for your application and provides answers to questions about SPC data, charts and chart interpretation. The user manual is thorough and each chapter provides instructions (complete with a flowchart) on how to set up for a particular type of analysis.

 Other features include free technical support; an online tutorial; multiple charts on one screen; multi-user access; Auto Chart (a useful feature that aids in importing and charting external data); real-time charting; alarms (based on a wide range of out-of-control tests, including user defined rules); and access to external data imported from an ASCII file, copied from the Windows clipboard or linked to an ODBC-compliant program (e.g., Excel).

 SQCpack is a well-designed program that takes much of the hassle and fear out of SPC. Given its features, the package is reasonably priced, even for small companies. If you're in the market for an SPC package, take a look at this one.

Menu Level Above 

This Menu LeveL 

Menu  Level Below 

[Contents] [News] [WebLinks] [Columnists]
[Applications] [Software] [SPC Guide] [Letters] [First Word] [Books]

Copyright 2000 QCI International. All rights reserved.
Quality Digest can be reached by phone at (530) 893-4095. E-mail:
Click Here

Today's Specials