Six Sigma

An Overview of Minitab

and Microsoft Excel

Learning Objectives:

Understanding the primary tools used in Minitab and Excel

The complexity involved in manipulating some statistics formulae and

the desire to get the results quickly have resulted in the creation of a

plethora of statistical software. Most of them are very effective tools at

solving problems quickly and are very easy to use.

Minitab has been around for many years and has proven to be very

sophisticated and easy to use. It has also been adopted by most Six

Sigma practitioners as a preferred tool. The statistics portion of Microsoft

Excel’s functionalities does not match Minitab’s capabilities but

because it is easy to access and easy to use, Excel is widely used by professionals.

2.1 Starting with Minitab

From a Microsoft desktop, Minitab is opened like any other program,

either by double-clicking on its icon or from the Windows Start Menu.

Once the program is open, we obtain a window that resembles the one

shown in Figure 2.1. The top part of the window resembles most Microsoft

programs. It has a title bar, a menu bar, and a tool bar.

The session window displays the output of the statistical analysis

while the worksheets store the data to be analyzed. The worksheets

resemble Excel’s spreadsheets but their functionalities are totally

different. Some operations can be directly performed on the Excel

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24 Chapter Two

Title Bar

Menu Bar

Tool Bar

The Session window is used

to output the results

Minitab worksheet is different

from Excel spread sheet

even though they look alike.

They do not perform the

same functions and have

very few similarities and

capabilities

Figure 2.1

spreadsheet but would require extra steps when using Minitab. Minitab

does not offer the same flexibility as Excel outside of statistical analysis.

Column header without any text

Column names

Column header for column

containing a text

Column header for a column

containing dates

The worksheets come with default column headers. The default headers

start with the letter “C” and a number. If the columns are filled with

numeric data only, their headers remain unchanged; if the columns

An Overview of Minitab and Microsoft Excel 25

contain text data, “-T” will be added to the default header; if the data

contained in the columns are dates or times, “-D” will be added to the

default header.

Underneath the column headers we have the column names, which

are blank when the Minitab window is first opened. The column names

are entered or pasted with the data. These names are important because

they will follow the data throughout the analysis and will be part of the

output.

2.1.1 Minitab’s menus

Minitab uses some namings on the menu bar that are common to most

Microsoft products. The content and the layout of the File menu are

close to Excel’s File menu with a few exceptions. The shortcuts are the

same in both Excel and Minitab: Ctrl+n is for a new file and Ctrl+p is

for the print function.

File menu. The “New. . . ” option of the File menu will prompt the user

to choose between a new project and a new worksheet. Choosing a

new project will generate a new session window and a new worksheet,

whereas choosing a new worksheet will maintain the current session

window but create a new worksheet.

The “Open Project . . . ” option will list all the previously saved Minitab

projects so that the user can make a selection from prior work. The

“Project Description . . . ” option enables the user to save a project under

a new name along with comments and the date and time.

Will show existing previously

saved Minitab projects in

Microsoft open dialog box

The last projects worked on {

{

Store the project name,

location, date and

comments

Adds a new worksheet to the

project, saves existing one

} Import data from other filesor

existing database

26 Chapter Two

Edit menu. Except for “Command Line Editor,” “Edit Last Dialog” and

“Worksheet Links,” all the other options are the usual options found on

Microsoft Edit menus. The “Command Line Editor” opens a dialog box

in which the user can type in the commands they wouldwant to execute.

When a value is missing from a set of data in a column, Minitab uses

an asterisk (*) to fill out the empty cell. The “Edit Last Dialog” option

enables the user to modify the default symbol. The symbols may not

change on the worksheet, but once the data are copied and pasted to a

spreadsheet, the selected symbols will show.

Used to add and / or manage

new links to the project

Data menu. The Data menu helps organize the data before the analyses

are conducted. The first option, “SubsetWorksheet . . . ,” generates a new

worksheet and the user can determine what part of the data from the

existing worksheet can be exported to the new one and under what conditions

that operation is to be done.

An Overview of Minitab and Microsoft Excel 27

Used to copy and paste dat

from active Worksheet to a

new one. This is done filling

up the fields in the dialog

box that opens up when the

command is clicked.

Divides data in a selected

worksheet into several

worksheets.

Also used to unstack data

Combines open worksheets

into one

Convert Columns into

rows and rows into

columns Combines several columns

into one

Divides previously stacked

columns into several

columns

Calc menu. The Calc menu enables options such as the Minitab Calculator

and basic functions such as adding or subtracting columns.

Generates the Minitab

Calculator which is different

from the standard

calculators. {

Provide basic statistics

calculations for row and

columns

Helps speed up basic

calculations such as

subtracting the mean from

every observation in a

column

...