Help Manual

Contents






Sigma Magic Help Version 18

Run Chart

Overview

A Run Chart can determine if the input data set is stable. It specifically looks for four things: trends, mixtures, oscillations, and clusters. If any of these are present in the data, the data set is reported as unstable.

This tool can be added to your active workbook by clicking on Graph and then selecting Run Chart.

Inputs

Click on Analysis Setup to open the menu options for this tool. A sample screenshot of the menu is shown below. inputs
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Chart Type: Specify the format of the chart. This selection is not enabled since there is only one format available.
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X Axis: Specify the type of x-axis to plot for the run chart. The available options are:
OptionDescription
IndexUse index values (1, 2, 3, ...) for the x-axis.
DatesUse dates for the x-axis. You will need to specify the dates column for this plot.
3
Subgroup Type: Specify if the data contains groups. The available options are:
OptionDescription
NoneThe data does not contain any groups.
ConstantEnter the value of the subgroup size in the input dialog box. The data contains groups, and the specified subgroup size determines the groups. The data entered from the Analysis Data section contains a single column of data that must be continuous.
VariableThe data contains groups, and the group information is specified in the input data file. Enter the data in two columns. The first column contains group information, and the second contains analysis data. Note that the group column can be categorical or continuous, but the data column has to be continuous.
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Subgroup Size: Specify the subgroup size for this analysis. This input is enabled only if you specify the value option as the data format.
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Help Button: Click on this button to open the help file for this topic.
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Cancel Button: Click on this button to discard any changes and close the dialog box.
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OK Button: If possible, click this button to save any changes and compute the analysis outputs.

Data

You will see the following dialog box if you click the Data button. Here, you can specify the data required for this analysis. Data
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Search Data: The available data displays all the columns of data that are available for analysis. You can use the search bar to filter this list and speed up finding the right data for analysis. Enter a few characters in the search field, and the software will filter and display the filtered data in the Available Data box.
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Available Data: The available data box contains the list of data available for analysis. If your workbook has no data in tabular format, this box will display "No Data Found." The information displayed in this box includes the row number, whether the data is Numeric (N) or Text (T), and the name of the column variable. Note that the software displays data from all the tables in the current workbook. Even though data within the same table have unique column names, columns across different tables can have similar names. Hence, it is crucial that you not only specify the column name but also the table name.
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Add or View Data: Click on this button to add more data to your workbook for analysis or to view more details about the data listed in the available data box. When you click on this button, it opens the Data Editor dialog box, where you can import more data into your workbook. You can also switch from the list view to a table view to see the individual data values for each column.
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Required Data: The code for the required data specifies what data can be specified for that box. An example code is N: 2-4. If the code starts with an N, you must select only numeric columns. If the code begins with a T, you can select numeric and text columns. The numbers to the right of the colon specify the min-max values. For example, if the min-max values are 2-4, you must select a minimum of 2 columns of data and a maximum of 4 columns in this box. If the minimum value is 0, then no data is required to be specified for this box.
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Select Button: Click on this button to select the data for analysis. Any data you choose for the analysis is moved to the right. To select a column, click on the columns in the Available Databox to highlight them and then click on the Select Button. A second method to choose the data is to double-click on the columns in the list of Available Data. Finally, you can drag and drop the columns you are interested in by holding down the select columns using your left mouse key and dragging and dropping them in one of the boxes on the right.
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Selected Data: The list box header will be displayed in black if the right number of data columns is specified. If sufficient data has not been specified, then the list box header will be displayed in red color. Note that you can double-click on any of the columns in this box to remove them from the box.
6a
Response Variable: This list box contains the data used to create the run chart. This list box is mandatory, and one column must be specified. Note that the values specified in this column must be numeric.
6b
Subgroup Variable: This list box contains information about the subgroups used to create the run chart. This list box is enabled only if you specify that the subgroup type is a variable in the setup tab. This list box can contain either numeric or text data. The number of rows of data in this column should match the number of data in the response variable. For example, suppose you specify values 1, 1, 1, 2, 2, 2, 3, 3, 4, 4, 4. In that case, the first three data points are grouped into Subgroup 1, the following three data points are grouped into Subgroup 2, the following 2 data points into Subgroup 3, and the subsequent 3 data points into Subgroup 4, etc.
6c
Date Variable: This list box contains information about the dates to use to create the run chart. It is enabled only if you specify the X-axis type as Dates in the setup tab. Ensure that the number of rows of data in this column is the same as the number of data in the response variable and that the format for the dates has been correctly entered.
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View Selection: Click on this button to view the data specified for this analysis. The data can be viewed in a tabular format or a graphical summary.

Charts

You will see the following dialog box if you click the Charts button. Charts
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Title: The system will automatically pick a title for your chart. However, if you want to override that with your title, you can specify a title for your chart here. Note that this input is optional.
2
Sub Title: The system will automatically pick a subtitle for your chart. However, if you want to override that with your subtitle, specify a subtitle for your chart here. Note that this input is optional.
3
X Label: The system will automatically pick a label for the x-axis. However, if you would like to override that with your label for the x-axis, you can specify a different label here. Note that this input is optional.
4
Y Label: The system will automatically pick a label for the y-axis. However, if you would like to override that with your label for the y-axis, you can specify a different label here. Note that this input is optional.
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X Axis: The system will automatically pick a scale for the x-axis. However, if you would like to override that with your values for the x-axis, you can specify them here. The format for this input is to determine the minimum, increment, and maximum values separated by a semi-colon. For example, if you specify 10;20, the minimum x-axis scale is set at 10, and the maximum x-axis scale is set at 20. If you specify 10;2;20, then, in addition to minimum and maximum values, the x-axis increment is set at 2. Note that this input is currently disabled, and you cannot change this setting.
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Y Axis: The system will automatically pick a scale for the y-axis. However, if you would like to override that with your values for the y-axis, you can specify them here. The format for this input is to determine the minimum, increment, and maximum values separated by a semi-colon. For example, if you specify 10;20, the minimum y-axis scale is set at 10, and the maximum y-axis is set at 20. If you specify 10;2;20, then, in addition to minimum and maximum values, the y-axis increment is set at 2. Note that this input is optional.
7
Horizontal Lines: You can specify the values here if you want to add a few extra horizontal reference lines on top of your chart. The format for this input is numeric values separated by semi-colon. For example, if you specify 12;15, two horizontal lines are plotted at Y = 12 and Y = 15, respectively. Note that this input is optional.
8
Vertical Lines: You can specify the values here if you want to add a few extra vertical reference lines on top of your chart. The format for this input is numeric values separated by semi-colon. For example, if you specify 2;5, two vertical lines are plotted at X = 2 and X = 5, respectively. Note that this input is optional.

Verify

If you click the Verify button, the software will perform some checks on the data you entered. A sample screenshot of the dialog box is shown in the figure below. Verify The software checks if you have correctly specified the input options and entered the required data on the worksheet. The results of the analysis checks are listed on the right. If the checks are passed, they are shown as green-colored checkmarks. If the verification checks fail, they are shown as a red-colored cross. If the verification checks result in a warning, they are shown in the orange exclamation mark, and finally, any checks that are required to be performed by the user are shown as blue info icons.
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Item: The left-hand side shows the major tabs and the items checked within each section
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Status: The right-hand side shows the status of the checks.
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Overall Status: The overall status of all the checks for the given analysis is shown here. The overall status check shows a green thumps-up sign if everything is okay and a red thumps-down sign if any checks have not passed. Note that you cannot proceed with generating analysis results for some analyses if the overall status is not okay.

Outputs

Click on Compute Outputs to update the output calculations. A sample screenshot of the worksheet is shown below. outputs
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Notes: The notes section contains the input summary - specifically the number of rows of data, the number of distinct groups, and the confidence level. The analysis results section contains the overall median and the P values for trends, oscillations, mixtures, and clusters. If any of these P values is less than alpha (default: 0.05), it is reported as unstable. The conclusion reports whether the data is random or if any specific pattern is observed.

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Graphs: The graphs section contains the run chart of either individual values or averages for each subgroup, and an overall median is shown. The number of runs is calculated based on the overall median value.

Notes

Here are a few pointers regarding this analysis:
  • Run Charts are much simpler to create but less comprehensive than a Control Chart.
  • Control Chart includes control limits and lets you know when you encounter special causes and when you need to adjust the process.
  • A Run Chart does not include any control limits. It can, nevertheless, help you identify trends, clusters, and outliers in your data.
  • It provides more information than a regular Time Series Plot.

Examples

The following examples are in the Examples folder.
  • Create a Run Chart for the data in the reference file and determine if the data has any trend. (Run Chart 1.xlsx).



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