An important reason to use NWA Quality Monitor for data entry is its ability to provide real-time alarms and to perform actions based on the alarms. The real-time alarms give you immediate visual and/or audio feedback on product quality. Quality Monitor can automatically save the alarm list, send an email, or perform other actions immediately or upon the completion of the record.

One of the seemingly deep mysteries of SPC (and often-asked questions for NWA Technical Support) concerns the relationship between Histogram 3 sigma limits and Control Chart 3 sigma limits. The limits are used for different purposes: Histogram limits evaluate process capability, Control Chart limits separate common variation from special variation. Still, two main factors produce confusion:

A common question is "Which control chart should I use?" Although the answer can become deep and complex, here are some simple recommendations.

First decide what type of data you're dealing with.

• Variable data takes on a measurable, numeric value. There are many possible values.
• Attribute data consists of categories. There are only a few (usually two) discrete values.

With variable data, decide how large subgroups are.

NWA's software supports using "Pattern Rules" on control charts. While control limit violations are triggered when a single subgroup is beyond a control limit, pattern rules are triggered by an unusual pattern of consecutive subgroups. Because patterns involve more than one subgroup, they are more sensitive to smaller, sustained changes than control limit violations.

For routine procedures, it's hard to beat the convenience of a desktop shortcut. Fortunately, it's easy to add a shortcut to an NWA Quality Analyst^® Run file:

1. Find the Run file (it has a .RUN extension) in Windows^® Explorer.
2. Right-click the Run file and select Create Shortcut from the pop-up menu. (The shortcut will appear in the list of files in Windows Explorer.)
3. Drag the shortcut to the Windows Desktop.

Now, when you double-click the shortcut, the Quality Analyst Run file executes.