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WaveRIDER
®
In the real world you may not want or be able to run your WaveRIDER through your
wave solder machine continuously to collect process data. A more typical scenario is to
check the machine by running the WaveRIDER through periodically: once per shift,
once per day, once per week, or once after every maintenance cycle. In addition
checking the wave solder machine at the start, middle or end of every part number run,
at the start and end of every part number run or once during a part number run could be
typical scenarios. Make sure you generate SPC charts based on data sets that had the
same set points each time. Otherwise the charts will not be meaningful.
While SPC had its start in high volume repetitive operations, SPC is applicable to many
other types of operations as well. However SPC can be difficult to apply to short runs.
Short runs may be runs that take a short time to process, runs in which multiple
samples are difficult to collect, and runs where samples are difficult to place into
subgroups or runs where small quantities are run at a time.
There are several basic short run SPC techniques:
1) Nominals Charts
2) Individuals/Moving Range Charts
3) Moving Average/Moving Range Charts
4) Standardized Formula Charts
The Moving Average/Moving Range Chart technique is particularly well suited for
situations where control information is desired as soon as possible and there is a
relatively long time between sample collections. After considering the nature of wave
solder operations and the wave solder machine sampling process, the Moving
Average/Moving Range Chart technique was incorporated into WaveRIDER SPC.
