SPC History
The SPC History window displays a line chart of the SPC values collected for a specific process variable and job. It includes two graphs. The top graph is a plot of X-bar values collected from the selected job and the bottom graph is a plot of the associated range values.
The X-axis is the time at which the SPC values were recorded. The number of values graphed may be a subset of the total collected. On the top graph, the Y-axis is the X-bar value collected for the selected job and process variable. On the bottom graph, the Y-axis is the range value. The rightmost point is the most recent value for the process variable and job.
There is a scroll bar at the bottom of the graph that allows you to scroll through the SPC values. As you slide the scroll bar, you see the X-axis change. The range of the scroll bar is shown below the scroll bar. The value on the left is the time of the first SPC data (the oldest data). The value on the right is the time of the latest SPC data collected for the process variable and job. To view more data, slide the scroll bar to the left. Move the scroll bar to the right to view more current data.
The number of plotted values on both graphs is changeable using the Size field. If the size is set to 100, then 100 SPC samples are plotted. Changing the size does not change the value of the scroll bar. It only changes the 'depth' of the data selection.
The X-bar mean value for each graph is shown as a solid gray line. The upper and lower control limits are dashed blue lines. The upper and lower specification lines are shown on the X-Bar graph as dashed red lines.
Where can you find it?
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| · | Choose the History menu on the main your system window.
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| · | Choose the SPC History option.
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What do you want to know about?
General Functions:
| SPC Statistics Concepts
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| Changing Machines
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| Changing Jobs
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| Selecting Process Variables
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| Displaying Standard SPC Statistics
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| Exporting Data
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| Closing the Window
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Graph Functions:
| Changing the X-axis
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| Changing Rescaling Options
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| Viewing Actual Values
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| Viewing Maximum and Minimum Values
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