by Rehman Khan, guest blogger
If you don’t already know these 10 tips you will get much more benefit if you work along with the example. You don’t need to download any files to work along—although, if you don’t have Minitab already, you may want to download the free 30-day trial.
First I will list my 10 tips, and then as we go through the examples I will highlight where they are going to be used. The 10 tips are
- Using the Auto-Fill function.
- Making patterned text data.
- Using Set Base when generating random data.
- Using the Edit Last Dialog Box function.
- Clearing a menu.
- Setting the order of a categorical axis on a graph.
- Updating a graph.
- Making a Similar Graph, which is especially useful when formatting has been changed.
- Using the Layout Tool.
- Using Conditional Formatting.
We are going to generate 3 columns of data which will have 30 rows in each column. Column 1 is called Shift, it relates to a production process where there is a Morning, Afternoon and Night shift. Columns C2 & C3 are two yield values, which are recorded for each shift. Remember this blog is about learning 10 useful Minitab tips rather than learning to examine the data for this process.
First, start a new Minitab project and type in the column headings shown. Then type ‘Morning’, ‘Afternoon’ and then ‘Night’ in successive cells after shift.
Tip 1: Using the Autofill function
We could copy-and-paste the first three cells 9 times to make our 30 rows of data. But instead, we can highlight the three cells and then grab the Fill Handle and drag that down to Auto Fill our text. Try that now but don’t go too far down.
Tip 2: Making Patterned Text data
Another way of getting Minitab to do all the laborious typing is to use the Make Patterned Data command. Select Calc > Make Patterned Data> Text Values... Complete the menu as shown and click OK.
Now we will randomly generate two columns of yield data to simulate the performance of the shifts. However, random data is not as random as you might think.
Tip 3: Using Set Base when generating random data.
The Set Base command fixes the starting point of Minitab’s Random number generator. So even though we are generating random data on different machines at different times, using the same starting point ensures that Minitab will give you the same random data that it gives me. Select Calc > Set Base... Then enter 3 as the Base for the random number generator and click OK.
We are going to use a Uniform distribution for Yield1. Go to Calc > Random Data > Uniform… then complete the menu as shown and then click OK. Because we used the Set Base command, all of our randomly generated data will be the same!
Tip 4: Using the Edit Last Dialog Box function
This is the must-know tip for Minitab. To quickly navigate to the last dialog box you had open, press the control key and then press ‘e’, written as ‘ctrl+e’. Alternatively, press the edit last dialog icon in the tool bar as shown. This should have re-opened the dialog box we used to generate 30 rows of random data from the uniform distribution.
Tip 5: Clearing a dialog
To completely clear a dialog box, just press F3. This is very useful, since it will clear sub-dialogs as well. Press F3 to clear the menu now. Complete the menu as you did to create the Yield1 data, but this time store the data in column Yield2. Your data should look like the screenshot shown.
For the next part of the demonstration we need to produce a graph. Go to Graph > Bar Chart...
From the Bar Represents drop-down menu, select ‘A Function of a Variable.’ Ensure that One Y Simple is selected and then click OK. Complete the dialog box as the screenshot shows. Then click OK to produce the chart.
Tip 6: Setting the order of a categorical axis on a graph
Notice that the chart’s X-axis labels are in alphabetical order. This is the default for Minitab but we sometimes need to change the order to be user-friendly.
To change the order of the x-axis variables,go to the worksheet and
place the active cursor anywhere in column C1. Right-click and then select Column Properties > Value Order… There are a number of options available, but we will set the radio button for Value Order to ‘Order of occurrence in the worksheet’ as shown.
Tip 7: Updating a graph.
We can now either recreate our graph—or we can update it. Look in the top-left corner of the graph. The yellow warning triangle and circular blue arrows mean that the graph is out of sync with the data in the worksheet. To update the graph, right-click on it and then select Update Graph Now. You also have the option of keeping the graph automatically updated. Note: some graphs cannot be updated, they must be recreated when data are changed.
Tip 8: Making a Similar Graph, which is especially useful when formatting has been changed.
The next graph shown is the same as the one you should have open, but I have changed the format to meet a fictitious company standard. If I need to make similar graphs and not repeat the formatting adjustments every time, there is a shortcut for doing this. First, ensure the graph is selected by left clicking on it. Then go to Editor > Make Similar Graph…
The dialog allows basic changes to the graph. Change ‘Yield1’ to ‘Yield2’ in the new variable column.
Then Click OK to produce the similar graph for column Yield2.
Tip 9: Using the Layout Tool
We already have two graphs. To demonstrate our next tip, let’s also make two boxplots for Yield1 and Yield2, respectively. If we want to display these four graphs on the same plot we can use the Layout Tool to make a multi-graph plot using existing graphs. Select any graph and then go to Editor > Layout Tool…
On the top-left of the layout tool we can change how many plots are shown. We will use a 2x2 layout but Minitab can go up to 9x9.
The Layout Tool is an easy to use, but is best learned through a bit of experimentation. Try arranging and ordering the graphs in different ways. When you are done click on the Finish button.
Note that you can change the formatting of the new plot can by just as you can adjust other graphs.
Tip 10: Using Conditional Formatting
For the final tip, I am going to give you a brief introduction to Minitab's conditional formatting tools.
If I wanted to quickly identify my best performers—which we’ll define as those with a Yield1 greater than 95—in the Project Window, I can use Conditional Formatting. Go to Data > Conditional Formatting > Highlight Cell > Greater Than...
Complete the dialog as shown, then click OK. You’ll see the results in the data sheet. Conditional Formatting is very useful when sanitizing large data files.
I hope you have enjoyed learning about my 10 favorite Minitab tricks, and that you find them helpful the next time you’re analyzing your own data!
About the Guest Blogger…
Rehman Khan is the author of Six Sigma Statistics using Minitab 17 and also Problem Solving and Data Analysis using Minitab. Recently he has started his own Youtube channel called RMK Six Sigma. Rehman is a SigmaPro Master Black Belt and Charted Chemical Engineer. He works for FMC Chemicals Ltd in the UK as a Manufacturing Excellence Engineer.