Description

Short information about this SFC chart

Chart Type

The type of control chart you are adding or modifying. All control chart types are for variable data.

Individuals: Displays each collected data value of the material characteristic being measured separately

Individuals and MR: Displays each collected value and the moving range for each collected value, using two charts. Displays each collected value separately on a single chart. Displays the moving range for each collected value on a single chart.

Median: Calculates and displays the median of each subgroup. This chart type is used when it is desirable to give little weight to occasional wild shot values. The median chart should be used only when subgroup sizes are small since the efficiency of the median in estimating the true universe mean decreases with increasing subgroup size.

Moving Average: Calculates and displays the moving averages of each subgroup

Moving Range: Calculates and displays the moving range of each subgroup

Process Capability: Displays a normal curve superimposed over a histogram of data, along with calculated values associated with the process capability

X-Bar and R: Displays the mean and range of each subgroup. The X-Bar chart calculates and displays the mean of each subgroup. The R chart calculates and displays the range of each subgroup.

X-Bar and S: Calculates and displays the mean and standard deviation of each subgroup. The X-Bar chart calculates and displays the mean of each subgroup. The S chart calculates and displays the standard deviation of each subgroup.

From Chart Template: Uses SPC chart template that is defined in SAP MII Workbench, and makes Chart Template a required field.

Note that if you select X-Bar and R, X-Bar and S, or From Chart Template type, the system enables fields on the Secondary Chart tab page.

The following short run chart types can be used by choosing the corresponding regular chart and selecting the Short Run checkbox. For short run charts, the calculated value is the collected value minus the target value for the material.

Short Run + Individuals: Displays each calculated value separately, for multiple materials on the same chart.

Short Run + Individuals and MR: Displays each calculated value and the moving range for each calculated value, using two charts. Displays each calculated value separately, for multiple materials, on a single chart. Displays the moving range for the calculated values, for multiple materials, on a single chart.

Short Run + Moving Range: Calculates and displays the moving range of each subgroup, for multiple materials, on a single chart.

Short Run + X-Bar and R: Displays the mean and range of each subgroup, using two charts. The X-Bar chart calculates and displays the mean of each subgroup, for multiple materials, on a single chart. The R chart calculates and displays the range of each subgroup, for multiple materials, on a single chart.

Subgroup Size

The number of data points to be collected per plot point for this control chart. For Individual charts, this field is fixed at 1. For Median charts, the entered number must be between 2 and 25. For all other charts, the entered number must be between 2 and 30.

Max Plot Points

The maximum number of plot points displayed on this control chart. A number between 2 and 100 is recommended.

Max Data Age (Days)

The maximum age (in days) of the data points to be used in the analysis and the chart display

Note that this field and the Max Plot Points field are interrelated.

Chart Template

The full path to the SPC chart template that is defined in SAP MII Workbench to use for this chart (see Display Template).

If blank, SAP ME uses the predefined template for the selected chart type.

Propagate Alarms

If selected, allows the system to generate an alarm message if an associated SFC trend rule conditions are met (see SPC Alarm Severity Maintenance).

Create Messages for All Alarms

Enabled only if Propagate Alarms is selected.

Selected: Creates a message for all the alarms for an SFC number

Deselected: Creates a message for one alarm for an SFC number

Short Run

If selected, the created chart is a short run chart of the type selected in the Chart Type field.

It supports the following chart types:

X Tick Label

Defines the type of labeling for each subgroup along the X Axis.

Sequential (1 to N): Displays a number starting at 1, and incremented by 1 for each subgroup

Time: Displays the time the data was entered

Date: Displays the date the data was entered

Date/Time: Displays the date and time the data was entered

SFC: Displays the SFC number for which the data was collected

X Axis Label

The label displayed along the X-axis of the control chart

Scale

Determines whether the chart's Y-axis scale is linear or logarithmic (based on powers of 10)

Control Limit Options

None: Control limits are not used.

Fixed: Control limits are fixed as you specified.

Note that the upper and lower control limits specify the threshold values at which the process output is considered to be statistically “out of control”.

Calculated: Control limits are calculated from the process data and the sigma coefficient.

From Chart Template: Uses control limits from the SPC chart template that you specified on the Main tab page.

Upper Control Limit

The maximum value above which the process is considered to be statistically “out of control”. It is typically set at three standard deviations above the center line.

Center Line

The mean of the values plotted on the chart.

Lower Control Limit

The minimum value below which the process is considered to be statistically “out of control”. It is typically set at three standard deviations below the center line.

Sigma Coefficient

The number of sigma, or standard deviations, used to calculate the upper and lower control limits

Spec Limit Options

Fixed: Specification limits are fixed as you specified.

Note that the upper and lower specification limits specify the threshold values at which the process output is considered to be statistically “out of specification”.

From Chart Template: Uses specification limits from the SPC chart template that you specify on the Main tab page

Upper Spec Limit

The maximum value above which the plotted value is considered to be “out of specification”.

Target

The specified (nominal) value for the characteristic being plotted.

Lower Spec Limit

The minimum value below which the plotted value is considered to be “out of specification”.

Display Spec Limits on Chart

If selected, you can see specification limits on an SPC chart.

Enable Trend Rules

If selected, allows you to specify SPC trend rules that are used to determine if a manufacturing process is in a state of statistical control. These rules are used during the SPC analysis (see SPC Alarm Severity Maintenance).

Trend Rules

The identifier of the group of the trend rules.

Use Chart Template Rules: Uses trend rules from the SPC chart template that you specify on the Main tab page