ATS SPC stores measuring and charting jobs as ‘batches’ in a database. A batch may be as simple as a measurement of length or diameter made with a digital calliper or as complex as, say, an engine cylinder block measured using several gauging fixtures, weight scales, and other instruments.
Each characteristic to be measured is known as a ‘feature’ - a physical length or diameter, or hole depth, or perhaps a weight, a density, or electrical resistance. A feature is any property that may be measured and assigned a numerical value.
Each feature has a measurement unit, an expected value, and usually one or two tolerance limits. In ATS SPC, a feature also has a source of measurement data, and a statistical type – basic, mean/range, or mean/sigma. In a Basic feature, data is collected one measurement at a time and plotted directly into histograms and scatter charts. In a Process feature data is collected in subgroups of typically 5 measurements. The mean and the standard deviation or range of each subgroup is plotted in a control chart. ATS SPC supports subgroup sizes of 2-25 readings.
To reduce measurement and transcription errors to a minimum, ATS SPC supports direct connection to measuring instruments and can show live values from the instruments as they are used to measure your parts. This ‘real time feedback’ gives you greater confidence in the measurements and allows you to correct instrument handling problems as they happen.
ATS SPC supports data entry from many electronic instruments and allows you to use them individually or combined in mathematical expressions to calculate features that cannot be measured directly.
Features may be measured individually, as when hand held instruments are used for simple measurements of length or depth etc., or they may be grouped together as in a gauging fixture or automated measuring system where many features are measured at once. Such a feature collection is known in ATS SPC as a measurement set.
When you ‘enter’ a measurement ATSSPC records it in a database under the feature and batch to which it belongs. You can recall the data to produce process control charts and histograms etc. and to perform various types of statistical analysis such as calculation of control limits or process capability. ATS SPC can display these on screen or print them out if you need hard copy.
The ATS SPC database is Microsoft Jet (version 4) compatible so you can use Microsoft Access (2000 or later) or any other Jet v4 database product to examine the stored data and, if necessary, perform further analysis or reporting beyond that provided by ATS SPC itself.
ATS SPC has been designed to allow detailed control of users' ability to perform complex or potentially damaging functions. Casual users, for instance may be granted sufficient rights to allow them to collect and analyse measured data without them being able to accidentally (or wilfully!) delete the work of others. ATS SPC uses the Microsoft Jet/Access database security model and is compatible with all levels of security including fully encrypted databases.
To comply with the requirements of traceability standards such as 21CFR part 11, ATS SPC can operate a data signing regime. Each time you enter data, ATS SPC records who carried out the operation and signs the data record to prevent it being tampered with in the future. The same thing happens when you create a new batch, change control limits, or delete data. In fact you cannot delete data without trace – ATS SPC records the deleted data, who deleted it, and when it was deleted!
Throughout the ATS SPC package, if you press the F1 key this help window will appear with information relevant to the part of the program you were just using. You can also search for topics in the help system by pressing the Contents button at the top of the window, and browse through the help topics as you would a book, by pressing the << and >> buttons.
One special help item is the ‘About Box’, a special dialog that gives you important version information about your copy of ATS SPC. You will need this information if you ever need to contact ATS customer support. You can open the About Box by choosing About ATS SPC from the Help menu.