Variable Information

QW5 Help Files

The Variable Information screen displays all of the information about the variables in the Quality Window application template currently  open.


The arrows found to the left and right of the variable name across the top of the screen allow scrolling through the variables in the template.


Name

This is a unique description used to identify each variable in an application template.  It should be a description that tells the viewer in a glance what each variable is.  It can be any combination of characters, numbers and special characters.  Single (')and double (") quotes are not permitted. To make the name more readable it is recommended that you capitalize the first letter of all key words in the name.


The name of a variable can be displayed on the Log Sheet screen in up to three rows by the use of the underscore character "_".  Place this character in the name and QW will format the name accordingly.


Example: Oven_Temp._Reading will be displayed as


Oven

Temp.

Reading


Type

A Quality Window variable can be:



Average

An A-average type variable is used to collect a set number of values and then return the average of the values entered.  The A-average type variable works with the R-range type variable to return the range of the values entered for the average.


Average information is entered through the Add, Edit, Copy or Insert screens.  It can be charted, used in calculations and can have rules and limits assigned to it.  The length of the variable must include an allowance for a decimal point and sign if required.


The No. of Values to Average prompt is used to indicate the number of values that are to be averaged and the size of the popup window on the Add/Edit/Insert/Copy screen.  This value must be greater than 2.  Once the values have been entered in the popup window the individual values are discarded and only the average is maintained. 


A second method of calculating an average is through the use of a C-calculated type variable using the @AVG function.


Note:For Average type variables Standard Deviation is multiplied by the square root of the No. of Values to Average (sample size).


Calculated

A Calculated variable has its value derived based on a formula that you specify.  C-calculated variables do not appear on the Add/Edit/Insert/Copy screens.  The value of a calculated variable is determined when the Save key is press on any of these screens.


A C-calculated variable can be charted, used in other calculations and can have rules and limits assigned to it. 


The length of the variable must include an allowance for a decimal point and sign if required.


Lookup

A L-lookup type variable is a calculated text field.  It uses a value from another variable as a key to a Popup Selection file to obtain Popup Fields information.


A L-lookup variable does not appear on the Add, Edit, Insert, Copy screens.  Its value is only determined when the Save button is clicked on the Add, Edit, Insert, Copy screens.


Numeric

A N-numeric variable can be a combination of numbers (0-9), signs (+ implied or -) and a decimal point (.)


The length of the variable must include an allowance for a decimal point and sign if required.


It can be charted, used in calculations and have rules and limits assigned to it.


Popup

A P-popup type variable is used to provide a list of valid selections for a particular question or prompt.  Once the answer is picked it is stored in the P-popup variable.  The list of selections available in a popup is pre-defined and the user can select from the list presented.


A P-popup variable can be a single question with one list of selections or it can be a number of dependant questions, maximum 9, with different selections for each question.  The number of questions or levels you select for a P-popup variable is determined when the Popup Selection File (file extensions QPT,QPD,QPI) is created.  Each level in a Popup Selection file has one "Popup Level" associated with it to a maximum of 9.  This means up to 9 dependant questions can be asked in one P-popup variable.


Range

A R-range type variable can only be used in conjunction with an A-average type variable.  It is used to display the range of values entered for the A-average variable.


The R-range variable is a calculated type of variable meaning it does not appear on the Add/Edit/Insert/Copy screens.  Its value is calculated once the Insert key is pressed to save the data on any of these screens.


A R-range variable can be charted, used in calculations and have rules and limits assigned to it.


The length of the variable must include an allowance for a decimal point and sign if required.


Text

T-text variables can be used to enter a combination of alphabetic (A-Z) or numeric (0-9) data.  A good use of a text variable is a comment field.


A text variable can not be charted and therefore has no target, control or specification limits and is always displayed in black on all screens.


Length

This is the number of characters that will be permitted for entry on the Add, Edit, Insert and Copy data screens as well as the display length for the variable on these screens and the Log Sheet.  For numeric values (Type N-numeric, C-calculated, A-average and R-range) the length of the variable should include the decimal point as well as a sign (+ or -) if required.


Decimals

The number of decimal places to the right of the decimal place.


Example: 592.61 has an overall length of six (6) with two (2) decimal places.


Report Type

The Report Type option for N-numeric, C-calculated, A-average and R-range type variables provide you with additional options on how statistics are calculated for a variable in order to meet specific needs. 


Type V - Variable


A normal numeric variable is typically accompanied by the reporting of Cr, Tz, Cpk and C%OOL.  The inference in a variable is that there is value in reducing variation and running on target.


Type VT - Target Range


A Target Range report type is used for variables that are not responding against a specific Target value but rather a Target Range.  The Target Range is defined by the limit values selected for the Upper and Lower Warning limits for the variable.  You may want to review the Control Rules activated for this Report Type to ensure they match your control strategy for this variable.


The calculation of Target Z is the only statistic affected by this selection.


Average greater than the Upper Warning Limit

Target Z set to 1 (one)

Average between Upper and Lower Warning Limits

Target Z set to 0 (zero)

Average less than the Lower Warning Limit

Target Z set to -1 (minus one)

       

Type A - Measurable Attribute


This report type is used for variables for which you only care if the variable is in specification or not.  For this report type you are typically not attempting to minimize variation but only avoid defective situations.


The following statistics are disabled and displayed as N/A for this Report type:  Cr, Tz, Cpk and COOL


Type A1/A3/A5/A10/A20/A30 - Attribute Count


An Attribute Count Report Type is used for variables that you wish to count the number of specific items found for a pre-determined number of samples.  This could be the number of containers found to be over-filled from a group of five (A5) bottles selected at random from the production line.


The following statistics are disabled and displayed as N/A for this Report type:

Cr

Tz

Cpk

COOL


The Percent Observed Out Of Limits (OOL) calculation is modified as follows:


(Average/Attribute Count) * 100 where Attribute Count is 1,3,5,10,20 or 30 depending on the item selected



Unit of Measure

The Unit of Measure is an 'information only' field that appears at the top right of the Add, Edit, Copy and Insert screens and can be used as a Report Statistic on the Report option in Views


Sampling Plan

This is an option that can be used to direct the user when a value should be entered for a variable.  Depending on the value entered here QW will cause the Variable Reference Number (V##) to flash on the ADD or EDIT screens.  The flashing V## is a reminder to the user to enter a value for this variable. 


The Sampling Plan Feature does not force a value to be entered for a variable, it only alerts a user that an entry is expected.  The Sampling Plan feature is active each time the Add screen is requested and also when the Edit screen is accessed for the editing of the last or most current record in a data file.


The V## will flash on the Add or Edit screens until a value is entered.  Once a value is entered QW will turn the flashing off.


A Sampling Plan value of 0 through 99 can be entered in this field.


A value of zero, 0, indicates the feature is disabled and the entry of this variable is optional and QW will never flash the V## for this variable.


A value of one, 1 indicates that a value should be entered for each new record that is added to the data file.


A value of 2 to 99 indicates that QW should only flash the V## after reviewing the previous entries for this variable and determining if an entry is required.


In the case of a sampling plan of 2, QW will check the last record in the Log Sheet screen to see if a value was entered for this variable.  If that record has no entry for this variable then QW will flash the V## for this variable.  A 2 indicates a value is required every second record. 


A Sampling Plan of 6 indicates a value is required every sixth time a record is added, and so on up to a maximum Sampling Plan of 99.


Note:


QW only scans up to the current number of records in memory for the Sampling Plan feature.  If you had a Sampling Plan set to 20 and there are only 10 historical records loaded QW will only look at the those 10 records.  QW will not flash the V## number for this variable until there are at least 20 records in memory and they have no entries.


Required

Each variable in a Quality Window application can be defined as required, making it necessary for the user to enter a value on the Add or Edit Data screen.


If the user has not entered a value in a Required variable the cursor will return to that field when the Save button is clicked.


If a variable is defined as Protected the data can not be added, changed or deleted.


A Protected variable is useful when data is being added automatically fom an outside source such as a scale or PLC.


Calc. Limits Based On

Warning, Control and Specification Limits and Targets


The setting or calculation of limits (specification, control, warning and target) within QW 5.0 is governed by three variables:


  1. The type of limit (Fixed, Calculated or Blank) selected
  2. The type of Target (fixed, calculated or blank) selected
  3. The selected method for calculating standard deviation (S) selected


The following is an explanation of each of them:


1.    Types of Limits  -(Specification, Control and Warning)


        1. Fixed Values. Limits are fixed at a specific value with rational constraints placed on these limits

           (such as the upper control limit must be greater than the lower control limit).

        2. Continuously Calculated.  

                a.  Warning limits        = Target +/- 1.5S

                b.  Control limits         = Target +/- 3S

                c.  Specification limits  = Target +/- 4S

        3. Blank.   Disables that limit and any associated control rule calculation


2.     Selecting type of Target

        1. Fixed Value.

        2. Continuously Calculated Average for the Population or corresponding with the Selected Subgroup

        3. Blank.   (If blank, the target used for a limit calculation would be Population Average.)


3.     Selected method for calculating the Standard Deviation (S)

        a.        Population uses the entire population of data

        b.        Moving Range Estimate = ((MR bar * 3.267) - MR bar) / 3

        c.        Lowest consecutive average found for a Selected Subgroup

        d.        Lowest consecutive variation found for a Selected Subgroup

        e.        Highest consecutive average found for a Selected Subgroup

        f.        Highest consecutive variation found for a Selected Subgroup


The size or number of points for a Selected Subgroup is determined as follows:

        a.        20% of the total number of data points

        b.        a minimum of 10 data points

        c.        a maximum of 100 data points


Once the Selected Subgroup is determined the points that make up that group are used to calculate a Standard Deviation and Average value.  These values will be used to determine any limits that are set as calculated and any of the Methods selected from 3 c, d, e or f.above.


Centered On

The Centered On dropdown allows the setting of how the Target value is to be represented on the chart screens.


Max Value / Min Value

Are used for two purposes in QW.  The first use is to validate the entries made on the Add/Edit/Insert/Copy screens for a numeric type variable.


If the Maximum Value is set at 100 and the Minimum Value is set at 50 only values greater than or equal to 50 and less than or equal to 100 will be accepted.  The second use of these limits is to scale the Control Chart and Relationship charts as well as the Capability Bar on the Histogram.


QWSETUP requires that all Fixed Limits - USL, UCL, UWL, TARG, LWL, LCL, LSL - be between the Minimum and Maximum values.


The Maximum and Minimum Value have a default value of the largest and smallest value possible based on the length of the variable.


Example: Length of Variable is 5 with no decimal places then the Maximum value is 99999 and the Minimum of -9999.


Upper Spec. / Upper Control / Upper Warning / Target Value / Lower Warning / Lower Control / Lower Spec.


The limits set in a QW application are the basis for the colors displayed throughout QW.  This includes the colors that numerical data is displayed in on the Logsheet, Add, Edit, Insert and Copy screens as well as the color bands on the Control Charts and Histograms.  There are two parameters that can be set for each limit.  They are the type of limit and the actual value for the limit.


The Type of Limit is a one character identifier that sets the limit type.  It can be F-fixed, C-calculated or B-blank. 


A F-fixed limit is one which is assigned by the application creator at his or her discretion and is normally based on either product, process or customer requirements. 


If a limit is defined as F-fixed then a value for the limit must be entered.  The limit entered must meet edits based on the length of the variable, decimal places and the value of other limits.  The editing based on the other limits set follows this order.


Maximum >= USL >= UCL >= UWL >= Target >= LWL >= LCL >= LSL >= Minimum


To interpret this the Maximum Limit must be greater than or equal to (>=) the USL - Upper Specification Limit and the USL must be greater than or equal to the Upper Control Limit, and so forth, down to the Minimum Limit.


The number of decimal places for an entered limit is always one more decimal position than the number of decimal places set for a variable.  This is done to allow for a clear definition of whether a value entered on the Add or Edit screen is out of specification or out of control. It avoids the following problem:


With the USL set at 50 is 50 within specification or outside specification?


Setting the USL to 50.1 here means that entering 50 on the Add screen will indicate the value is within specification and 51 is out of specification.  Using this feature consistently for all variables and applications  eliminates the problems the above question can create.


A C-calculated limit tells QW to automatically calculate the limits when the application is selected from the B-Begin screen and also each time information is Added, Edited or Deleted.


The value of each limit is determined as follows:


Upper Specification Limit (USL)

plus four standard deviations (+4S)

Upper Control Limit (UCL)

plus three standard deviations (+3S)

Upper Warning Limit (UWL)

plus one and one half standard deviations (+1.5S)

Target (TGT)

Average

Lower Warning Limit (LWL)

minus one and one half standard deviations (-1.5S)

Lower Control Limit (LCL)

minus three standard deviations (-3S)

Lower Specification Limit (LSL)

minus four standard deviations (-4S)

       

A B-blank limit is used to exclude a limit for a variable.  This means if the Control Limits are set to B-blank then there will be no Red control bands on the Control and Histogram Charts and no value will be displayed in red. 


If you set all limits to B-blank for a numeric variable then the value entered for that variable will always be displayed in black on all screens.   Also that variable can not be viewed on any graphs such as Chart, Relationship or Zoom as well as never be displayed on the Summary screen.   


Editing of Limit and Type Combinations - there are a number combinations of particular limits and types that are not valid and would be rejected by QWSETUP.  You must correct these conditions before QWSETUP will allow you to proceed.  The following conditions must be met:


The upper and lower combinations for the same type of limit (USL/LSL,UCL/LCL,UWL/LWL) must be the same type or B-blank.


Warning limits (UWL/LWL) can not be C-calculated if the Control Limits (UCL/LCL) or the Target are set to B-blank.


Rules

A check mark to the left of the Rule indicates that this rule is currently active.  To activate/de-activate a rule use the Up and Down arrow keys to position the highlighted bar on the rule and then press the Space Bar.  Each time you press the Space Bar the check mark will appear or disappear indicating the status of that rule for this variable.  If a rule is de-activated (no check mark) the corresponding letter (A-Z) will not appear on the Fields Detail screen.


If you disable all rules for a variable then it will not appear on the Summary screen in QW.  If you disable all control rules for all variables in an application QW will not default to the Summary screen after data has been added or edited. 


Refer to the Rules section in QWSETUP for details on creating and setting the priority of rules.


Input/Output File

This option provides you with the ability to get data in and out of individual variables in a QW application.  Input files, as the name implies, are used to get data from outside QW for a single variable into QW when the A-Add key is pressed.  An example of this would be providing a default value for a variable on the Add screen.  Output files store data for a single variable when the INS key is pressed on the Add or Edit screen for the last record in a QW application data file.  This is useful for sharing information between QW applications.


Both Input and Output files are simple DOS comma delimited ASCII files that contain one record or element of information.  Here is an example of what an Output File created by QW would look like.


        129.5,"1990-02-18","14:04:16"


All fields in this Input File are separated by a commas.  The format of the data, <129.5>, should be in the exact format that was defined in the QW application template for this variable.  Text values are enclosed in quotes and numeric values are not.  Text information should be left justified and numeric information right justified.


The example is one which was generated by QW as an Output File for a variable.  The date and time is included to identify when the entry was created.  If the Input File information is generated by an external program the date and time are not required, but are recommended.  Each record should be terminated with <CR><LF>, carriage return and line feed (ASCII character codes 13 and 10 respectively).


If an Input file is specified, but does not exist, the Input file is ignored.  If an Output file does not exist and one is specified QW will create the file.  If the file does exist it is overwritten with the new information.


An Input or Output file name can be up to eight characters in length and have a three character extension.  You may also specify the names with full DOS Path support.  The name specified must conform to DOS file name constraints.  Refer to your DOS Manual for details on DOS File and Path standards.


QW will obtain the value from the Input File when the <A> key is pressed to select the Add data screen.  The value from the Input File is placed in the variable on the Add screen before the Add screen is presented.  This value is then provided as the default value for that particular variable.


An Input File always contains the last value stored to it.  It is not erased after each Add function.


Input Files can have a number of uses such as setting of a default value for a variable when it is displayed on the Add data screen.  An Input File can be used with an Output File of the same name to create a default value which will change based on the last entry made for a variable in the Add data screen.


Using Input Files also permits you to share information that may have been entered in a different QW application or obtained from a source external to QW.  An external source could be from another information system or our utility program QWRS232 attached to a measuring device such as a weight scale.  Refer to the QWSETUP-Applications-General section of this manual under the prompt "Batch file to Execute when the A key is pressed" for information on executing DOS Batch files from QW.


Help File

If a filename is entered in the Help File field and the Var Help button is clicked the program associated with the file extension will be launched.


Example: If Help File filename is 007.htm the default browser will be launched


Category

The category field is an 'information only' field that appears at the top right of the Add, Edit, Copy and Insert screens and can be used to provide a means of defining groups of similar or related variables to make filtering easier in Views.


Example:


Assigning a Category of Weights for Weight_Lane 1_(gm), Weight_Lane 2_(gm) and Weight_Lane 3_(gm)


Assigning a Category of Weight Calculations for Weight_Average_of 3, Weight_Range_of 3, Weight Profile_All Lanes and Weight Profile_All Lanes_XbarR


X-Ref

This is the field that can be used to link a QW variable name to the name used by another software product. The Cross-Reference name entered on the Fields-Detail screen can only be extracted from the QW application data file using the Views option.


Cancel

Exits the current screen.


Apply Changes to Other Variables


OK