Minitab Introduction

An Overview of Minitab ver 12.2Type IErrora aType IIErrorb bCorrectDecision(1-a)a)CorrectDecision(1-b)b)90807060Y=50 X1 X2Fuel EconomyOctane LevelAir Temp252015105Subgroup04.34.24.14.03.93.83.7Sample Mean11X=4.0963.0SL=4.232-3.0SL=3.9590.60.50.40.30.20.10.0Sample StDev1S=0.14033.0SL=0.2409-3.0SL=0.03982Xbar/S Chart for Evaluations Statistical software package Has many of the tools needed to successfully analyze data with rigor-Graphs-Statistical tools for data analysis-Six Sigma Reports Descriptive Statistics Gage R&R Capability Analysis(ZST/ZLT)Graphing-Many Types!Pareto,Fish bone Hypothesis Testing Product&Process Six Sigma Reports Generation of Test Plans for Designed Experiments Analysis of DOE results Statistical Process Control Random Data Generation for simulationsSession Window(Keeps a running log of commands and outputs)Data Window(Similar to an Excel spreadsheet)What is a Dialog Box?The dialog box is the way to communicate your requirements to Minitab(variables,options,analysis methods,etc.).Three dots after a menu selection indicates a“dialog box”will appear when that item is selected.An arrowhead indicates there are more menu selections availableEnter your selections here.And here!Context Sensitive Help in Minitab is Really Helpful!Example of a Dialog Box:l Entered directly into the spreadsheet(the Data window)-Type the data directly in-Use the data entry arrow to choose how you wish to enter the data(in rows or in columns)l Copied/pasted-From MINITAB-From other“Windows”softwarel Imported/Linked-From many commonly used software packages-From saved text or ASCII filesl Generated by Minitab-Random data-Patterned data (Ex.:1,2,3,4,1,2,3,4.)-Reference data (subscripts that indicate the source of the data)When entering data in the Data Window,there are three important aspects:Data is normally entered in columns for ease of analysis(click on the small arrow in the upper left corner to change entry direction)Column headings are entered above the column,NOT in the first row (31 characters maximum)If an alphabetic character is typed in the first cell of a column,the entire column is converted to text1)As a Worksheet-Saves the data only.Save Current Worksheet(as)Save Worksheet as2)As a Project-Data,session text,graphs,and more.Save Project(as)(1)(2)Scenario:A new process has recently been installed to manufacture extruded plastic sheet in AP5.The existing process is still in service making sheet.We want to determine whether the two processes produce sheet of the same thickness.The CTQ for this process is sheet thickness.20 samples have been collected(5 subgroups with 4 samples per subgroup)taken at various times during the two-shift operation.Steps in the Process:1.Enter the data(Ys)in a spreadsheet2.Add columns with other useful information(Xs,subscripts,etc)3.Arrange the data for analysis(combine,stack,etc.)4.Graph the dataStart a blank worksheet and enter the data below into columns C1 and C2.Label your columns as indicated.Using the Enter key will always cause the cursor to move in the direction of the data entry arrow.(Make sure the arrow is pointing down)20 Data Points 5 subgroups(four data points taken at different times of day)The measurements are in thousandths of an inch.Column TitlesC1C2 ExistingNew128.6128.7128.8129.0129.0129.1129.1129.3129.0129.1129.1129.2129.1129.2129.2129.4129.1129.2129.1129.2129.0129.2128.8129.0129.0129.2129.1129.2129.4129.6129.3129.5128.8129.0129.2129.4129.0129.0128.8128.9Minitab Column HeadingsMinitab has features to make the adding of additional information easier than typing it in by hand.In this case,it would be very helpful to number the samples and indicate the time of day the sample was taken.First type in two new column headings:C3:Sample NumberC4:TimeSecond use Minitabs built-in feature for generating patterned data:For Column C3,we would like to indicate the sample number.Since there are 20 samples,C3 should contain numbers from 1-20.Heres how that data is created:A dialog box should appear.Fill it in as shown below:Heres what the data window now looks like:Now,lets fill in the times the samples were taken in Column C4.Remember,there were 5 subgroups of data with 4 samples each.Subgroups were taken at the following times:9:00 am 12:00 pm 3:00 pm 6:00 pm 9:00 pm Use the same menu command,but this time select“Date/Time Values”Fill in the dialog box as shown below:What does stacking mean?-Placing data from multiple columns into one or more(new)columnsHow is stacking done?-From the menu bar,choose:Manip Stack/UnstackChose Stack Columns or Stack Blocks of Columns-Fill in the dialog box as requiredMinitab(generally)needs data in columns to perform comparisons and statistical analyses.To manipulate all the data into the appropriate columns is called“Stacking”.What is it we are trying to do?Wed like to have one column with all of the thickness data(40 total points),and carry all of the additional information on sample number and time with each data point.NOTE:When more than one column needs to be stacked simultaneously,Minitab refers to the columns as“blocks”.From the menu bar,make the following selection:Fill in the dialog box as shown:1.Enter the columns you want stacked in the“Stack the Following Blocks”section.2.Enter the names of the new columns where the stacked data will be stored in the“Store stacked data in”section.3.Enter a column name in the“Store subscripts in”block.This column contains subscripts,which identify which data set from which the stacked data came.In this case,Existing and New equipment will be identified with a 1 and 2 respectively.Stack the 1strow on top of 2nd row and store the data in the new columns indicated.Why didnt we include the“Time”column in the dialog box?Because Minitab will not stack columns of different types!So how can we stack our“Time”column to correspond with the new stacked data in column C5(Thickness)?Use the“Stack Columns”subcommand,instead of“Stack Blocks of Columns”.Fill in the dialog box as shown below:Through this dialog box,you are telling Minitab to stack the“Time”column over itself,and store the stacked data in a new column named“Times”.Here is what your Data Window should now look like:Note:We have scrolled down the data set.The first line shown here is Row 8.