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QCTools

an Excel 97 AddIn

William F Lyle Copyright 1999

QCTools Version 1.0 Documentation

Installing QCTools as Excel 97 Add-in 1) Copy the QCTools.xla file into the Program Files\MSOffice\ Office\Library folder 2) Open an Excel spreadsheet 3) Select “Add-Ins” from the “Tools” menu

Select Add-Ins

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4) Locate Qctools in the list of available add-ins 5) Click the checkbox to select 6) Click OK to make QCTools available. The QCTools menu will now be added to the Excel menu at the top of the spreadsheet

Click to load QCTools

Click to Select

Note: If you place the QCTools.xla file in another directory than suggested above, then use the “Browse” button to tell Excel the location.

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Creating Histograms

Create histogram to analyze how this data is distributed

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1. Select data to be analyzed 2. Select “Histogram” from the QCTools menu

Select the data range

Click on “Histogram”

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3. Verify that the data range selected is what you desire to be graphed.

The range of cells selected will be displayed

Click “OK” to verify Click “Cancel” to select another range.

Note: If the range selected contains only one cell an error message (“Must Select Range”) will be displayed.

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4. Verify or change the calculated histogram parameters and then click “Display Histogram”.

This section allows you to change various graph parameters to provide a better visual comparison to another histogram

Lower and upper customer specification limit lines can be added

Select to print a “Statistics” sheet

Data statistics will be displayed

Calculated histogram information will be displayed

Click to display histogram

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5. Add your personal titles. You can use Excel drawing tools to add comments. The Histogram and Statistics sheets can be renamed and can be saved with the file.

Click to select a title and change as desired

NOTE: These graphs (once created) are not linked to the data as in other Excel graphs – so if you change the original data the histogram will not refresh. Other changes – like axis scales will cause the histogram to be incorrect. The best approach for these type of changes will be to delete the Histogram and Statistics sheets and regenerate the histogram.

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6. Review the Statistics sheet for detail information.

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Creating Paretos from raw data

Create Pareto chart to analyze frequency of categories

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1. Select data to be analyzed 2. Select “Pareto” from the QCTools menu

Click on “Pareto”


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3. Verify that the data range selected is what you desire to be graphed.

The range of cells selected will be displayed

Click “OK” to verify Click “Cancel” to select another range.

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4. Add your personal titles. You can rename the sheet if desired

First bar is automatically shaded. You can change if desired

Click to select a title and change as desired

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5. A separate statistics sheet is printed for detail information.

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6. Hi-lite all the bars you are selecting for further analysis. Click for fill

color options

Select Color

Select bar by clicking on the border

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7. Finished product

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Creating Paretos from summary data 1. Paretos can also be generated from summary data.

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2. Enter the summary data in the spreadsheet 3. Select the data range as shown (the program looks for 2 columns) 4. Click “Pareto” in the QCTools menu

Click on “Pareto”


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5. Verify the data range selected

Click “OK” to verify Click “Cancel” to select another range

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6. Change the titles as desired.

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Tips and Techniques 1) If you are building a histogram and there is a blank cell located in your data range, the program will assume it is a 0

(zero) and it will be used to calculate the statistics. This may or may not be what you intended. If you are building a pareto from raw category data, the program will treat a blank cell as a separate category. It will count the blanks and put in a category bar on the pareto that has no title. For these reasons you should avoid blanks in your data range. You can do so by sorting your data to put the blanks on one end and then selecting the non-blank cells only.

2) To select data for a histogram you can select cells that are either in one row or in one column. If you try to select an

area of the spreadsheet that contains multiple rows and columns an error message will be generated. 3) If you are building a histogram from data that has been calculated by Excel you may get unexpected results. Excel can

carry the calculation out to 9 decimal places and that will have an impact on how the class widths of the histogram are calculated. Changing the cell format will not help since that just sets how Excel displays the underlying number -- the cell value still has 9 decimal places. The only way to assure consistent results is to use Excel’s “Round” function to restrict the number of decimal places in the cell value. An example would be a cell that contains the formula “=a1/a2” where there is a 1 in cell a1 and a 3 in cell a2. The result of this calculation will give .333333333 as a cell value. However the formula “=Round(a1/a2, 3)” yields .333 as a cell value.

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Addendum to Tips and Techniques QCTools

Version 1.0.3 May 15,1999 1. For Pareto Charts, the program will now handle up to 100 bars (different categories). If there are more than 100 in your data the program will

fail. 2. As a practical matter, though, you will want to restrict your pareto charts to less than 15 categories. Here is an example of 84 categories….it is

a pareto chart but it is unusable.

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3. In paretos with large numbers of bars, the first cumulative % value on the cumulative % line may interfere with the data label above the first bar. If so, select the % label and move it with your mouse to a clear area. See below:

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Release Notes QCTools

Version 1.1.0 July 24,1999 In past versions of QCTools, the cumulative percent line on pareto charts was drawn by the program. This process caused some inconsistencies and also caused problems when the user wanted to change sizes of titles on the chart. With this version (v1.1.0) of QCTools the cumulative percent line is handled as another data series on the graph. Now if you make changes on the graph – like font size on a title – the cumulative line automatically redraws properly.

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