Charting Your Course
QI Analyst 3.5
by Matt Bartek
This software package by SPSS can play a key role in your process monitoring or process investigations. It provides real-time control charting, process capability analysis, and Pareto charts of causes and corrective actions for out-of-control processes.
QI Analyst directs the novice through the steps necessary to implement SPC monitoring. The comprehensive help screen doesn't make many assumptions concerning the operator's knowledge. And the online tutorial offers sound lessons on SPC basics. The tutorial runs several examples, which requires the actual setup of files, data input and printing of charts. Even for a quality engineer well-versed in SPC, the tutorial provides a great orientation to the software package. SPSS could, however, add tutorials covering editing and formatting, short-run SPC, setting up and modifying master files, and linking to external programs.
A great feature is the File Setup Wizard. It prompts users with questions related to characteristics, notes, causes and actions, data entry and gages, and finishes with questions on printing the completed chart. The comprehensive question-and-answer session takes some time, but it can lend a little confidence while control charting. The Wizard addresses many topics not covered in the tutorial, including setting up short-run SPC and linking the software directly to gages.
The graphics are basic but allow users to focus attention on the process being monitored or studied. When I first ran through the charts, the chart details were difficult to read, and the number of statistics would keep a statistician smiling for days. However, the charts and graphs can be made simple or detailed depending on the intended uses.
The chart gallery offers the standard list of charts, including X-bar and R charts, p charts, scatter plots, histograms, custom charts and the exponentially weighted moving average chart. The EWMA chart offers the option of charting the individuals or the averages. It assists users in detecting small process shifts and reduces the effects of noise inherent in much data.
SPSS addresses the calculation of control limits very nicely, utilizing either the past performance of a process or a selected number of the most recent points for establishing control limits. Even past control limits can be looked into for future charting. This option saves a lot of time. The control limits as well as the statistics can be controlled in this manner. My current anonymous SPC program requires data manipulation to investigate different periods of data. Automatically upgrading control limits based on recent data allows engineers and operators to spend time on corrective actions instead of calculating limits.
The individual files setup allows tracking of causes and actions related to out-of-control processes. This provides extensive documentation and tracking for corrective action plans. When an out-of-control situation occurs, users can choose causes of the situation from a pre-existing list or add a unique cause. The causes can then be charted on a Pareto chart, as can actions required to remedy an out-of-control situation. This allows users to find past actions to the same problems.
QI Analyst is user-friendly for engineers, technicians, supervisors and even managers, but does require users to have some computer know-how. Most operators can navigate Windows as easily as they can set up their machines, but for some operators the option of choosing between 10 drop-down screens and numerous files can be intimidating. Not everyone is familiar with Windows, and opening a file can cause some stress. Options are available for customizing interfaces that would simplify the interactions between the operator and QI Analyst. For instance, dynamic data exchange allows programmers to customize the interfaces, and restrict and control many options available to the user. However, modifying the interfaces to help operators use SPC software on a day-to-day basis with multiple users may require programming experience beyond the casual user. This is one area of QI Analyst that could be strengthened.
SPSS Inc. offers the public a very sound and comprehensive SPC software package in QI Analyst. The documentation found in the user manual, tutorials and the File Setup Wizard is excellent, providing an expert opinion only a few clicks away. SPC novices and experts alike can use QI Analyst as the cornerstone of a successful process control and corrective action program. All basics are covered, along with some nice features. QI Analyst should be considered by all those engineers and managers who want to spend their time improving the process rather than getting caught in the details of control charting.
About the author
Matt Bartek is an ASQ-certified quality engineer with Fasco Motors Group, which makes custom-designed electric motors.
QI Analyst 3.5
by SPSS Inc.
System requirements: 386 or better PC, 8 MB RAM, 6 MB free disk space, Windows 3.1 or higher, MS-DOS 3.1 or higher, VGA monitor.
Contact: SPSS Inc.
233 S. Wacker Drive, 11th floor
Chicago, IL 60606-6307
Telephone: (800) 543-2185
Fax: (800) 841-0064