Lean Line balancing

Flexible Line Balancing V.3 2001 LG ElectronicsUser Guide Distributed by Production Technology

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Setup

Flexible Line Balancing installation is normally done from thedistribution CD-ROM. Alternatively, you may copy the CDcontents directly to the hard drive of your computer and executethe setup procedure from that location. To start setup, select Runon the Windows Start Menu and enter the location and the setupprogram, such as D:SETUP.EXE (if D: is the letter assigned toyour CD-ROM drive). You may also start the setup program byselecting and double-clicking SETUP.EXE in Windows Ex-plorer.

When the setup program is executed, a series of screens willappear. The first two screens, shown following, introduce theprogram. Select the Next command button on the Welcomescreen to continue the setup process.


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In the next setup screen, select the location for installation ofFlexible Line Balancing files. The default, as shown, is to installfiles within the Program Files folder. To change the location,select the Browse button; otherwise, select Next. Select Cancelto abort the installation, or use Back to return to the prior screen.


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The Setup program will automatically copy required FlexibleLine Balancing files to your computers hard drive. Followingthe copying activity, the completion screen following will ap-pear. Click Finish to go on.


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You must restart your computer before using the program.Choose an option on the final setup screen shown following. Ifyou choose Yes, your computer will be shut down and rebooted.Choosing No will return your computer to normal operations.


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The Setup program will also place a Flexible LineBalancing shortcut icon on your Windows desktop.Double-click the icon or select it and press theEnter key to start the program at any time following

the installation process.

Modifying, Repairing or Removing the Program

At some future time, you may wish to make changes to theFlexible Line Balancing installation. Occasionally, files are cor-rupted or inadvertently deleted, causing problems in operation.At some point, you may also wish to remove the program fromyour computer. The Flexible Line Balancing files you originallyinstalled from the distribution CD-ROM provide these functions.

To modify, repair, reinstall, or remove the program, RunSETUP.EXE again. The installation program will detect the ex-isting files on your computer and display a series of maintenancescreens. The first screen, shown following, allows a choice ofMaintenance, Repair, or Removal of the software.

Select the desired option and click Next. In this example, Modi-fication is chosen.


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The screen shown next is the last display in the reinstallationprocess. Select Finish to end the process.


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The Repair and Removal options are used in a similar manner tothe Maintenance reinstallation shown. After selecting the desiredoption, you should follow the instruction screens as they appear.

Following a removal operation, a few files may remain in theFlexible Line Balancing folder. These may be deleted usingWindows Explorer.

Main Menu

You may start Flexible Line Balancing by selecting the programon the Windows Start Menu or by selecting or double-clicking ashortcut icon on the Windows desktop.

When the program starts, a Main Menu appears. There are fiveselections on the menu bar:


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Process: This selection enables you to define an assembly proc-ess by adding or inserting work tasks, their standard times, andspecifying sequential relationships between all tasks in the sce-nario.

Standard Elemental Task: This menu allows you to input andsave elemental task descriptions and standard times. After ele-mental tasks are saved, they may be recalled at any time andused to define a new Process.

Options: The Options menu allows you to set the appearance ofprecedence chart legends (on or off).

Help: This selection provides access to the Help file, instructionson How to Use Help, an option to Search the Help file, and theversion, copyright, and distribution information for the FlexibleLine Balancing program.

Exit: Closes the program and returns to the Windows desktop.

Note that you may use a hot key combination to select variousmenu actions. In many cases, you can hold the ALT or CTRLkey down and enter the underlined letter to choose the menuaction. For example, to select Process, use ALT + P. Alterna-tively, you may also make menu selections on any programscreen by clicking on icons that appear on the toolbar under theMain Menu choices. Icons are shown for many major programactions, and are provided with pop-up tips to indicate the ac-tion associated with each. Also, the status bar at the bottom of


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your screen will display a phrase which describes the function ofeach toolbar button as the mouse pointer is passed over it.

Process

The Process selection on the Flexible Line Balancing MainMenu allows you to start initial development of a line balancingsolution, do various file manipulations, import or export data,display information in alternative ways, or access Help files.

To begin work on a new Process scenario, select Process fromthe Main Menu. This will load a Process screen. Note that thescreen is divided into two areas, referred to as the Text Work-

place and the Graphic Workplace. The upper area (in gray) isthe Text Workplace and the lower (white) is the Graphic Work-place. The relative screen size of each workplace may bechanged by positioning the mouse pointer at the boundary of thetwo areas and dragging when the pointer changes to a two-

Text Workplace

Graphic Workplace


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headed arrow.

As shown in the illustration, the title bar of the screen will indi-cate Process: New1 the first time the screen is opened. Eachsuccessive opening of a new scenario will advance the count byone, i.e., New2, New3, etc. You may have unlimited Processfiles open simultaneously. After you name and save a Process,the title bar will indicate that file name.

The Text Workplace is provided for entering Standard ElementalTasks and the associated information required to build the Proc-ess. Note that the width of each column may be adjusted bymoving the mouse pointer to the vertical line at the top of eachcolumn and dragging the column wider or narrower. TheGraphic Workplace displays a precedence chart of work ele-ments as they are entered into the program in the Text Work-place area.

From left to right in the illustration, the fields are:

No: A sequential line number automatically generated byFlexible Line Balancing.

Proc #: Process number. An optional field that can be usedto further define the process steps.

Work Area: Enter the name of a work area. An optionalfield. You may use a department number, area name, cell,zone, or any desired description.

Elem Task Description: Enter a brief description for eachelemental task.

ST: Enter the standard time for each elemental task.


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Elem Task # (Elemental Task Number): This is an automati-cally generated unique number for each elemental task.

The next several column headings refer to how relationshipsbetween and among elemental tasks are defined. See the sectionon Elemental Task Relationships.

The last two columns are provided to insert text informationabout tooling and additional comments. Use of these columns isoptional.

The Process screen also shows a number of selections on themenu bar. These are used to perform file operations, editing ofwork elements within process scenarios, change the operatingcharacteristics of the program, and allow access to program Helpfiles.

File Menu

When you select File, a drop-downmenu offers several choices, whichmay be activated by a mouse click orby use of specified Hot keys.

Each click on New will open a newscreen. Use Open to access and loadan existing saved file, which can beselected from a list which appearswhen the command is used.

Import is used to access and load anexisting Process or Standard

Elemental Task that has been saved in Flexible Line Balancing.Save and Save As selections are used to save active FlexibleLine Balancing files under a current file name or an alternative


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name. The selections are active when a file is loaded. The func-tions are disabled until a file is loaded or a scenario is con-structed.

Delete is used to permanently remove a Flexible Line Balancingfile from your computers hard drive. Note that deletion cannotbe undone.

Print Preview allows you to view how the on-screen data andgraphics will appear when printed, done using the Print selec-tion.

The Print Setup choice allows you to do page formatting prior toprinting the on-screen information.

The Close selection will return you to the Flexible Line Balanc-ing Main Menu.

Edit Menu

When you select Edit, the following choices are shown, eachalso activated by a mouse click or by use of specified Hotkeys.

The Insert and Append selections add aline to the Text Workspace on theProcess screen. Insert adds the lineimmediately above the line selected (orthe first line if no others exist), andAppend places a new line at the endbelow the line selected (or the first lineif no others exist).

Delete permanently removes a line. Note that to remove or oth-erwise manipulate a line (e.g., for copy and paste). You can se-


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lect a line for deletion by clicking on any cell on that line. Ashort message will ask you to confirm any deletions.

Copy and Paste commands allow duplication of existing lines inthe analysis by selecting the line, copying, and placing to a newposition. The Paste selection is not enabled if nothing has beenselected and copied.

Run and Graph

Run and Graph are single-function choices (there are no drop-down sub-menus). Selecting Run will start the program actionsto solve the Process scenario and present a line balancing solu-tion. To execute a Run, you must have entered some number ofStandard Elemental Tasks into the Text Workspace. After se-lecting Run, a dialog box appears in which you must choose thebasis for work allocation, either Takt Time (cycle time), orWorker. This appears as follows:

If you select Takt Time, enter the desired time in seconds orminutes, and select OK. The time must be equal to or greaterthan the standard time of the largest Standard Elemental Task.

An error messagewill display if thetime selected istoo small.

If you selectWorker, you must

provide thenumber of

workers to be used in the assembly process. This can be anywhole number.


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If no errors are detected by Flexible Line Balancing, the pro-gram will begin the computations to solve the process scenario.An animated bar display will appear on-screen to indicate prog-ress toward a solution. Note that some time may elapse for solu-tion of very complex scenarios.

When computations are complete, Flexible Line Balancing willshow a graphical analysis of the allocation of work elements inthe problem. This includes notation of Takt Time, Neck Time,and a calculation of line efficiency. Task numbers are shownon the vertical bars that make up the graph.

After a graph appears, you may close the screen to return to theprior Process screen. While the current scenario is open, youmay use the Graph menu selection to display the current graphagain at any time.

If any changes are made in the work elements that comprise theProcess, use the Run command again to develop a current workallocation and graphical analysis.


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For more information about how to use the Graph feature, seethe discussion on What If ? Analysis.

Zoom Menu

Flexible Line Balancing provides zoom functions to allow con-veniences in viewing on-screen information. The Zoom menuallows normal screen viewing (1:1), or the ability to zoom In orOut to display information more legibly or effectively.

Each mouse click In or Out increases ordecreases the size of fields and characters inthe Text or Graphic Workspaces of theProcess screen. There is no limit to the sizeadjustment that can be made.

To increase or decrease text size, you must first have selected acell or line in the grid area. To use the Zoom function in theGraphic Workplace area of the screen, use the mouse to selectany node there before using the Zoom feature.

Window Menu

An additional convenience to the user is the ability to manipulatethe configuration of multiple windows on the screen. This maybe useful when two or more Flexible Line Balancing files havebeen opened simultaneously and you wish to view or manipulateportions of each.

If you select Cascade on the Windowmenu, the Text and Graphic Workplacescreens from opened files will be overlaidon the screen, much like stacked cards,with title bars and file names protruding.

You may activate any screen shown by clicking on its title bar.


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You can also use the Windows control boxes to display anyscreen full size or minimized, or to close a screen. The last en-tries in the drop-down menu indicate files currently open. Clickon any entry to display that file in the active window.

The illustration following shows three cascaded screens.

If you select Tile, either Vertically or Horizontally, the openedfile data will be displayed in a side-by-side manner, either top-to-bottom or left-to-right. The example of a Tiled screen fol-lowing shows three files opened and tiled Vertically. As shown,the topmost Process screen is active, since the title bar is blue.The Process screen at the bottom has just been opened, since noelements have been added to the Text Workplace.


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Help Menu

The Help Menu allows access to the main program Help file,plus additional functions.

The table of contents forHelp can be viewed by

selecting Contents. Whenthe Contents page

appears, you may easilyselect and view any topic

listed.

How to Use Help allows you to move directly to the Help filecontents which provide information about Windows Help files.Information is available about where to look, printing, copyingHelp topics, and many other Windows features. There is an ex-


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tensive discussion on the features of the Windows Help systemlater in this manual.

The Search selection allows you to find Help topics by enteringspecific search words. The Windows Help system scans its in-ternal database of words and phrases in the Flexible Line Bal-ancing file and lists all applicable Help sections for your review.

Choosing About Flexible Line Balancing displays a small screenwhich contains version, copyright, and distribution informationabout the program.

Standard Elemental Task

When you select Standard Elemental Task from the Main Menu,the screen shown following appears. As with Process, the screenis divided into two areas, the Text Workplace and the Graphic

Text Workplace

Graphic Workplace


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Workplace. The relative screen size of each workplace on thisscreen may also be changed with use of the mouse.

The Text Workplace is provided for entering information re-quired to build Standard Elemental Tasks which can then beused to build a Process scenario.

An Elemental Task may also be called a Work Element or anIndivisible Element. A Standard Elemental Task is a elementthat is used in building a Process later, on the Process screen.Standard Elemental Tasks have standard times and precedenceconstraints assigned to them. This is done on the Standard Ele-mental Task screen. A screen display is shown following whichcontains several Standard Elemental Tasks. These may benamed and saved as files, creating a library for use in buildingprocess scenarios.

Note that, unlike the Process screen, the Standard ElementalTask screen has no Work Area field.

The fields are:

No: A sequential line number automatically generated byFlexible Line Balancing.

Elem Task Description: Enter a brief description for each anelemental task.

ST: Enter the standard for each elemental task.


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Elem Task # (Elemental Task Number): This is an automati-cally generated unique number for each elemental task.

The next several column headings refer to how relationshipsbetween and among elemental tasks are defined. See the sectionon Elemental Task Relationships.

As in the Process screen, additional columns are provided foroptional user entry of information about tooling or notes aboutthe task.

Elemental Task Relationships

Each task in the line balancing problem must be identified withits sequence in the assembly activity. This is called precedence.To establish the computer model, you must enter several char-acteristics of each elemental task and its relationship to othertasks. The specific conditions that may be specified for each arelisted as follow:

Prec (Preceding Elemental Task Number): Enter the immediateprior Elemental Task Number or the several prior ElementalTask Numbers that are required to be completed before the cur-rent task.

When entering more than one task, separate the numbers withcommas. In the precedence diagram shown below, the tasks areindicated by circles. The first two Elemental Tasks (1, 2) do not

Selected Elemental Task Number: 3Preceding Elemental Task Number: 1, 2


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have preceding tasks. The solid lines and arrows between tasksindicate direction and sequence, left to right.

Sep (Separate Elemental Task Number): If a current task maynot be included in a work station assignment with another priortask, indicate this under the Sep column, entering the task num-ber that should be excluded. Graphically, this is displayed as ared dotted line between elemental tasks.

Ind (Independent Elemental Task Number): Select T if thecurrent elemental task is done by an operator as an independenttask, for example, an inspection operation. Select M if the cur-rent task is done by a machine as an independent task. If you donot specify either type, the automatic default entered will be F,which indicates neither of the prior types listed. The task isshown graphically as a gray circle.

Grp (Grouped Elemental Task Number): Grouped entries in-clude tasks that must be included in a common group with workperformed separately from other groups. Also, a task from onegroup cant be assigned at a workstation with a task from any

Selected Elemental Task Number: 3Independent Elemental Task Number: 3

Selected Elemental Task Number: 3Separate Elemental Task Number: 1


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other group. There can be more than one group in a specificproblem. Graphically, each elemental task that has been assignedto a group will show a common color for the circle indicating thetask.

In this example, one group includes Elemental Task Numbers 4,5, 6. The circles will appear as red in the Graphic Workplace.

Elemental Tasks 7 and 8 are in another group; these will appearas green in the Graphic Workplace.

Conn (Connected Elemental Task Number): Select a next fol-lowing Elemental Task Number that the current elemental taskmust be performed with. To state the constraint another way, thecurrent task should be an immediately preceding task to the con-nected task. This relationship is shown graphically with the ad-dition of a blue dotted line between the circles representing ele-mental tasks.

Cont (Contained Elemental Task Number): Enter a previous

Selected Elemental Task Number: 1Connected Elemental Task Number: 3


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elemental task number that the current elemental task shouldcontain. When Flexible Line Balancing executes Run, the stan-dard time of the contained elemental task will be internallyadded to the current elemental task. It is displayed as gray dottedarrow between elemental tasks (circles).

Program Features

Using Flexible Line Balancing, you are able to completely de-fine all steps in an assembly process and then determine the op-timum method of sequencing those tasks to insure the most effi-cient and productive output. In this section, several Flexible LineBalancing features and program options will be described.

Building a Precedence Diagram

A key factor in development of a balanced and efficient assem-bly process is the definition of elemental work tasks and theirplacement into a logical sequence. This is the function of theprecedence diagram, also called a precedence chart.

Precedence is the relationship of each given work element to allothers in a given model, in terms of which elements must pre-cede others and which are mutually exclusive (or independent)of another. Elements having no precedence are totally independ-ent of all others.

Selected Elemental Task Number: 3Contained Elemental Task Number: 1


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A precedence chart is a diagram of nodes which represent eachelement of work in a given model. The chart indicates sequenceof work and desired or necessary sequence and precedence ofactivities. The precedence chart usually contains a description ofthe work element, its position as a node relative to all others, anda standard or normal time for its execution.

Precedence charts are easily drawn in the Flexible Line Balanc-ing program. Each elemental task entered into the Text Work-place grid on the Standard Elemental Task (SET) screen auto-matically generates a node, shown as a circle. As the descriptionfor each task is entered, a new circle appears in the GraphicWorkplace. In the example following, three tasks have been en-tered, and three nodes of a precedence chart appear in theGraphic Workplace area.

Note that as nodes appear in the GraphicWorkplace, they are stacked together. Each circlerepresents a sequential task taken from the TextWorkplace grid, and each shows a consecutivenumber and the associated standard time. A green

rectangular box surrounds the most recent element entered or theone that is currently active in the Text Workplace.

At any time you may use themouse to drag elements anywhereon the graphics area, expanding

the diagram. When the example elements are separated, they areshown with interconnecting lines and arrowheads, as well as the


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appropriate standard times. If you have entered specific con-straints in precedence, such as Separate, Connected, Independ-ent, Grouped, or Contained tasks, the appropriate colored ordashed interconnecting lines will also appear.

When you have entered any number of elements to the StandardElemental Task workplaces, you may save the sequence to a filefor future use, which may include use of all elements or Import-ing of selected elements into another scenario. When you selectFile/Save on the SET menu, the following dialog box appears.

To save your work, enter a name for the file. In the example,Casting Check is used. An optional field is also provided forbrief notes about the saved tasks. Select OK to permanently savethe information, or Cancel to go on without saving.

To open a previously-saved file, select File/Open on the Stan-dard Elemental Task menu. A dialog box similar to the followingwill appear.


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Select the file to open and click OK to proceed. The file con-tents, both text and graphics, will be loaded to the SET screen,where you may modify, add, or delete elements. Select Cancel toreturn to the prior screen.

The Flexible Line Balancing program has virtually unlimitedcapacity to create complex precedence relationships and dia-grams. The example following is the Complex sample dia-gram provided with the Flexible Line Balancing program. Here,


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57 work elements are described and shown graphically.

Note that in this example, elements 51 through 57 have beenidentified as belonging to a different work group, as indicated bythe letter B in the Grp field shown below on the Processscreen.

As a result, the drawing generatedby Flexible Line Balancing willshow those elements in a differentcolor, in this case blue. All similarelemental constraints entered intothe Text Workplace will appear onthe precedence diagram that isfabricated in the Graphic

Workplace. The use of different screen colors, lines, and brokenlines allow you to easily expand the diagram and position ele-ments on the screen for best viewing.

Building a Process Scenario

In Flexible Line Balancing, you may build a Process scenariofrom either the Standard Elemental Task (SET) function of theprogram, or directly on the Process screen. If you are using pre-existing element descriptions and standard times which havebeen saved and filed within the program, you may wish to im-


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port one or more of those files into a Process.

If desired, you may work directly on the Process screen, creatingand saving elemental tasks as part of the Process file.

In the following example, a new process scenario is defined byentering a few Standard Elemental Tasks directly to a Process.Following that, additional Standard Elemental Tasks are im-ported to the Process from the Casting Check file illustrated inthe prior section.

First, open a new Process from the Main Menu, by selectingProcess.

On the Process screen that appears, enter data for desired tasks.In this example, three tasks are entered. The first line is createdin The Text Workspace by using Edit/Insert on the menu. Fol-lowing lines can be added using Edit/Append. When a blank linehas been added, you may type the data in appropriate fields.

At this point, you may elect to save these elements. As an exam-ple, the file is saved as Porosity Test. Also, if desired, the Pro-cess screen can be closed by using File/Close or the close tool-bar icon.


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To add pre-existingwork elements

(Standard ElementalTasks) to the three-

task Process justdefined, you should

use the File/Import menu selection on the Process screen.

In this example, the total desired Process will be built by addingother operations which were structured and saved as StandardElemental Tasks. These will be Imported to complete the Proc-ess.

On the main Process menu, select File/Import/Standard Ele-mental Task. Available saved SET files will be displayed in thelist that follows. Select the file Casting Check.

After clicking OK, the file contents are added to the Process


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Text Workplace following the existing three lines as shown fol-lowing. Notice that the added elements are automatically num-bered sequentially as numbers 4-6. Also, Flexible Line Bal-ancing automatically reassigns numbers in the Prec column toindicate correct precedence relationships for the added tasks.

In the example, assume that Tasks 4-6 must occur before Tasks1-3. This is corrected by using Edit functions to Copy and Paste.First, select the elements to be moved (Tasks 4-6) as shown inthe illustration below. After selection, click Edit/Copy to copycontents of these lines.

Finally, place the mouse cursor on the first line. This indicates tothe program that the first line of those copied will be placedthere. Now use Edit/Paste to place the lines in the Process. Theresultant Text Workplace now appears as follows. Note the newlines are automatically assigned new task numbers (7-9).


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Now, to finish the example, you must remove the last three lines,which are duplicates of those tasks moved to the beginning ofthe Process. To do this, select the last three lines and useEdit/Delete to remove the data from the Text Workplace. (Alter-natively, you can use the keyboard Delete key to remove data,but the lines will still remain. In this case, the blank lines can beused to input additional tasks, if desired). After deleting the un-wanted lines, the Text Workplace appears as below:

At this point, you have successfully integrated an existing Proc-ess file with additional tasks which were imported from a savedStandard Elemental Task file. To finish the Process scenario, youmust still review the precedence relationships shown. In the ex-ample, the last three tasks follow the first three; therefore youmust change the contents of the Prec column. With thesechanges, the resulting Text and Graphics Workplaces appear asshown following:


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The Import and Edit file functions in Flexible Line Balancingare versatile tools which can be used to rapidly fabricate Processscenarios in a variety of ways. Use of the Import function can beused to integrate existing Process or Standard Elemental Taskfiles, and the Copy and Paste commands can be used to quicklyrearrange the Process. Also, you can use the Edit/Cut,Edit/Insert, Edit/Append, or Edit/Delete menu commands tostructure the Process sequence.

Time Units

In Flexible Line Balancing, the unit of time used for the Stan-dard Time entry field (ST) is optional with the user. You mayelect to use seconds, minutes, or any other consistent unit. Thetime is recorded in Process and Standard Elemental Task filesand used to assign workstation time with the COMSOAL algo-rithm. You must be consistent. Do not intermix time units withina single problem. It is recommended you choose a constant unitand use that for all Flexible Line Balancing work.

Flexible Line Balancing will accept standard times to two deci-mal places. Also, it is not necessary to prefix decimal valueswith a zero when entering data. For example, enter .3, not 0.3.


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Graphics Legend

The Graphics Legend boxmay be turned on or off usingthe Options selection on theMain Menu.

The legend box, shown here,optionally appears on the Processscreen. It is used to identify thegraphic conventions used to con-struct precedence diagrams inFlexible Line Balancing. You mayclose the legends box at any timeby selecting the Close commandbutton.

In the illustration shown, Separateis a red dotted line, Connected isblue, and Contained is gray.Independent tasks are represented

by a gray circle, and Grouped tasks are shown as blue circles.All Preceding tasks are connected with a black line and arrow-head.

These conventions of color and style are used consistentlythroughout the program to indicate constraining conditions inwork flow and task requirements. The Graphics Legend box isshown only on the Process screen.

Doing a What If? Analysis

A powerful feature of Flexible Line Balancing is the ability toperform a line balancing computation on a defined Process, thenrevise the result incrementally. In the following example, the


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sample file Simple has been opened on the Process screenusing the File/Open menu selection.

The loaded file appears as shown. Note 1) that the GraphicsLegend is On in this example, and; 2) that the elements ofwork are not assigned to workstations since the program linebalancing computations have not yet been made. Also, the op-tional user entry field Work Area has no information yet.

As example, a Takt Timeof 18 has been entered tothe Run Criteria dialogbox. Alternatively, anumber of workers orworkstations could havebeen specified


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After selecting OK, the example Process is Run. Followingcompletion of Flexible Line Balancing calculations, results arepresented graphically.

With the given elements, precedence relationships, and specifiedTakt Time, this is the best result possible, as computed by Flexi-ble Line Balancing. The analysis shows a relatively poor workallocation over six workstations, with an efficiency of 80.4%.On the Graph, the selected Takt Time of 18 is shown, and alsoNeck Time, which is the duration of the longest set of work ele-ments.

To achieve a better result, Takt Time may be varied and theproblem run again as many times as necessary to achieve a bet-ter result, within your production conditions.

To achieve a better balancing solution, the problem is Run again,


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with a trial Takt Time of 19. You may use any desired cycletime, but the selection must be equal to or greater than the lengthof the longest Standard Elemental Task.

This yields a somewhat better solution, with efficiency of86.3% and five workstations. If five, rather than six workstationsare satisfactory, this may be an appropriate solution. Rememberthat Flexible Line Balancing always arrives at the optimum so-lution, considering precedence, constraints and the specified run

criteria, either Takt Time or number of workers. The programmay literally examine hundreds or thousands of alternative solu-tions during the Run process to arrive at the most productivebalance. To make a significant change in the result, one or morework elements or other constraints must be changed.

When the Run has been completed and the graphical result ex-amined, you may close the Graph screen and return to the Proc-


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ess screen. Notice now that the Standard Elemental Tasks havebeen combined into operations or workstations as shown on thegraph. In this example, there are five workstations or processareas where tasks are grouped. These five groupings correspondto the color-coded nodes on the precedence diagram shown inthe Graphics Workplace.

Each time you execute a Run in Flexible Line Balancing, thework elements are reallocated and grouped by the Proc # field.

At this point, you can also enter auxiliary information to theWork Area field if desired. In the example, the Work Areas havebeen identified as Assy area 1, Assy area 2, and Finalassy. This may be done before or after the Run.

You may repeat the Run procedure any number of times, varyingeither the Takt Time or the number of workstations until an ac-ceptable solution is reached. At that point, you should name andsave the Process file, using the File/Save menu command on the


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Process screen.

Using Interactive Graphics in What If? Analysis

Flexible Line Balancing offers an alternative method to examinework task allocation on the program graph. In this case, you canthe computer mouse to move elements directly on the graph pro-duced by running the Flexible Line Balancing program.

Returning to the earlier example using a Takt Time of 18, youmay click on any element of work to assess the possibilities ofcombining it with other tasks at different workstations. In thiscase, we have selected Task 8, which is then highlighted in yel-low. When you select a work element, it will be highlighted inyellow and some other elements at remaining workstations willappear in blue. In the example shown, element 7 at station 2,element 9 at station 4, and element 12 at station 5 are now dis-played in blue.

Blue

Yellow


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Elements shown in blue are those which Flexible Line Balancinghas determined are representative locations where the yellowtask in question may be moved. To move the yellow task to anew location, simply click your mouse on one of the bluetasks shown; Flexible Line Balancing will move the candidatetask to the workstation of the blue task selected.

Flexible Line Balancing may not show any elements in blue; ifthis happens, it is because the candidate task is constrained frommoving from its current location. Conversely, many tasks mayappear as alternate locations for the selected item. When thisoccurs, it is indicative there are few constraints in the prece-dence diagram.

To further illustrate, Task 8 will be moved from station 3 to sta-tion 4, where it will be placed with existing Task 9. After click-ing on Task 9, Flexible Line Balancing re-computes the workallocation and displays a revised graph. In the illustration, notethat the program has now joined Task 8 to Tasks 9 and 12 in


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station 4. However, the instantaneous efficiency calculation doneby Flexible Line Balancing shows this was not a prudent move,since efficiency has slipped to 75.9% from the prior 80.4%. Thissolution should probably be discarded.

As illustrated, Flexible Line Balancing gives you easy-to-useand versatile tools to examine various work combinations in anytype of what if ? situation. Remember that the Run alwaysproduces an optimum solution for line efficiency. If specifictasks are subsequently moved, it is generally done to accommo-date other considerations not shown in the precedence con-straints, and usually results in lowering efficiency.

As a final note about the Graph function, remember that the lastgraph executed is the one which will be displayed when theGraph menu command on the Process screen is used. If youname and save a Process file and exit the program, you may dis-play the same graph the next time the program is used by se-lecting the Graph command after the file is reopened.

Printing Results

Flexible Line Balancing allows you tofully format, preview, and print allinformation and graphics that are viewedon screen at any time. This isaccomplished using the print functions onthe File menu which appears on both theProcess and Standard Elemental Taskscreens and also the Graph screen. BothStandard Elemental Task text informationand precedence charts from the GraphicWorkplace may be printed. Using theProcess screen as example, the File menu

includes functions for Print Preview, Print Setup, and Print.


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After selecting File, click on the Print Setup menu function. Us-ing the dialog box that appears next, you may adjust severalprinting parameters, including choice of printer, paper size andsource, and page orientation, either portrait or landscape.

Following Print Setup, you may also wish to preview the printedresult. Do this by clicking Print Preview.

This will display a graphic approximation of how the printedpage will appear. An example (partial screen) is shown follow-ing.


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Note that the Print Preview screen includes several controls toassist in viewing. You may zoom in or out on the displayed pageby positioning the mouse pointer over the page and clicking, oryou may use the Zoom In or Zoom Out command buttons. Also,you may display one or two pages, and advance from page topage with the Next or Prev Page controls. If satisfied with theview, you may send the page directly to the printer with the Printcommand button. If you choose to print, either from this previewscreen or from the File/Print menu command, a printing dialogbox will display. This display will allow you to make severalchoices about the printing task, including page numbers to print(or all, or a selected section), number of copies of each page, andwhether to print to paper or to a file. If your printer has the ca-pability, copy collation may also be an option. To access addi-tional settings for your specific printer, select the Propertiesbutton.


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You may preview and print all areas of both the Text andGraphic Workplaces on Process and Standard Elemental Taskscreens. When you wish to print the text information, place themouse in that portion of the screen and select any cell on thegrid. When you wish to print a precedence diagram from theGraphic Workplace, click on any node in the chart. These ac-tions will instruct the Flexible Line Balancing program to pre-view the desired area, either text or graphic. Following is anexample print preview of the Graphic Workplace (partial pageshown).

You may also setup, preview and printthe graphs generated by using the Runmenu command on the Process screen.The illustrations show the menu choiceson the Graph screen and an example ofprint preview for a graph.


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Print Setup and Print options for printing a graph are identical tothose used for printing text or precedence diagrams from theProcess or Standard Elemental Task screens.

Graph Menu Selections

The Graph screen that appears when a Process has been Rundisplays a number of menu choices which are similar to thoseappearing on the Process and SET screens.

Shown below, the Main Menu bar allows you to access severalfunctions, including a Zoom control, a Window viewing con-trol, information About Flexible Line Balancing, and an array ofHelp commands.

The File menu, shown in the prior section, displays commandsfor Print functions and Closing the Graph screen.


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Zoom andWindow

functions areidentical to those

for the Processand SET menusdiscussed earlier

in this manual.

Error Messages

As in any complex computer software, there are possibilities forerror and anomalous outcomes in use of the Flexible Line Bal-ancing program. In most cases, erroneous user inputs will resultin on-screen error messages, similar to the example shown.

In this case, the userattempted to use theEdit/Paste commandwithout having any

lines yet entered in anew file.

In another example, a Run is attempted with a user-input TaktTime less than the standard time of the largest work element.The resulting message is shown.


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In general, Flexible Line Balancing error messages do not causea fatal error in the program performance. They are, as indicatedby the icon, informational in nature. You should click OK, cor-rect the procedure which caused the error, and go on.

Many other messages relate to the precedence data you haveused in the program.

In the case shown here, the error message indicates a logic con-flict in precedence between two tasks in a Process. In this case,the message tells you the exact cause of the problem.

If you encounter a problem which locks your computer, bothon-screen and keyboard, it is probably a non-recoverable situa-tion. In many cases, the data and precedence relationships inputby the user have a problem that cause the COMSOAL algorithmcalculations to enter an infinite loop. In this case, shut down theFlexible Line Balancing program by use of CTRL-ALT-DELkeys to end the task. Restart the program and re-examine thetask structure you have built. If problems continue, divide yourProcess into smaller groups of tasks, and run an initial groupingfirst. If successful, add subsequent task groupings until you dis-cover the problem cause.

It is advised you always save the Standard Elemental Task orProcess files you have built before executing a Run.


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Sample Files

Flexible Line Balancing includes sample files for your use inbecoming familiar with the program. These are named Com-plex and Simple. Both files may be opened from either theProcess or the Standard Elemental Task screens.

You should actively use these files to gain familiarity withFlexible Line Balancing procedures and conventions, includingall the edit functions and file saving and manipulation proce-dures. You can also execute several runs and move elements toestablish What If? scenarios. You may also build new proc-esses using selected tasks from these files.

If you use the sample files, you should Save them by othernames, so that the original files remain intact. In this manner,you will always have access to the originals without possibleneed for reinstallation from the distribution CD-ROM.

Importing and Exporting Data

You may import data to Flexible Line Balancing from an exter-nal source or copy its data and paste to another location, such asa spreadsheet. To do this, use the copy and/or paste functionswithin Flexible Line Balancing and the external application(such as Microsoft Excel).

Open the two applications, select the desired data in either loca-tion, and copy. This will place the data on the Windows Clip-board. In the opposing location, paste into the appropriate cells.

As an example, to paste data from Excel to Flexible Line Bal-ancing, type Element Task Description in the third column of anew worksheet, type the Standard Time in the fourth column,and type a unique identification number for each Elemental Task


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in the fifth column as above. Select and copy these rows, then goto the Flexible Line Balancing screen and use Edit/Paste on theStandard Elemental Task menu.

After using the Paste command, you will have the followingscreen.

Elemental Tasks numbered 1,2,3, and 4 are automaticallychanged to the proper sequence of numbers in Flexible LineBalancing. In the illustration following, the last prior existingElemental Task was #57. When the new data is pasted to thegrid, the program automatically assigns proper numbers for them(58, 59, 60, and 61).

In doing this process, you should be cautious to be sure the datahas been placed into the desired cells and that none has beenoverwritten or lost. When all desired information has beenmoved, check the precedence relationships and make adjustmentas necessary.

Documents

Lean Line balancing