NAT'L INST. OF STAND & TECH REFERENCE NBS

PUBLICATIONS

MISTIR 86-3471-1

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The Internal Revenue

Service Post-of-Duty

Location Modeling

System: Users Manual

Version 4.0

Paul D. Domich, Richard H. F. Jackson, and Marjorie A. McClain

U.S. DEPARTMENT OF COMMERCE

National Institute of Standards and Technology

(Formerly National Bureau of Standards

Center for Computing and Applied Mathematics

Gaithersburg, MD 20899

September 1988

\

National Bureau of Standards became the

National Institute of Standards and Technology on August 23, 1988, when the Omnibus Trade and

Competitiveness Act was signed. NIST retains

all NBS functions. Its new programs will encourage

improved use of technology by U.S. industry.

A Report to: The Research Division

Internal Revenue Service

Washington, DC 20224

1 ~QC

II

inn

- U 5 6

86-3471-1

1988

U.S. DEPARTMENT OF COMMERCE

C. William Verity, Secretary

NATIONAL BUREAU OF STANDARDS

AND TECHNOLOGY

Ernest Ambler, Director
<<<
I NISTIR 86-3471-1

The Internal Revenue

Service Post-of-Duty

Location Modeling

System: Users Manual

Version 4.0

Paul D. Domich, Richard H. F. Jackson, and Marjorie A. McClain

U.S. DEPARTMENT OF COMMERCE

National Institute of Standards and Technology

(Formerly National Bureau of Standards

Center for Computing and Applied Mathematics

Gaithersburg, MD 20899

September 1988

A Report to: The Research Division

Internal Revenue Service

Washington, DC 20224

*» ABSTRACT

This report is a user's guide for a microcomputer package which was m designed by the National Institute of Standards and Technology to assist the

Internal Revenue Service in choosing locations for its posts -of- duty which

will minimize costs to the IRS and to the taxpayer. The user may select the

types of costs to be considered and may specify potential locations for new

i

posts -of -duty . The system displays maps showing workload for a district,

| current post-of-duty locations and new post-of-duty locations. This manual

provides hardware and software requirements for the system, installation

procedures, data file formats, and detailed operating instructions.

I
'
TABLE OF CONTENTS

«•

Section I: Introduction 1

A. Description of Reports 1

B. Introduction to the System 2 C. User Assistance and Future Releases 3

Section II: Computer Requirements 4

A. Hardware 4

B. Software 4

Section III: Setting Up the System 5 A. Contents of the Distribution Disks 5 B. Installing the System 6 C. Description of Data Files 7

Section IV: Using the System 12

A. Overview 12

B. Entering the System 16

C. Displaying Workload 18

D. Displaying or Modifying Initial POD Sites 23

E. Solving for Optimal POD Locations 28

F. Displaying Optimal POD Locations 32

G. Reporting Zip Code and Staff Assignments 36

H. Exiting from the System 37

Index 38

*

i
*1 

.
Section I: Introduction

A. Description of Reports

This paper is one of a series of reports documenting the Internal

Revenue Service Post-of-Duty Location Modeling System, which was developed

for the IRS Research Division by the Center for Computing and Applied

Mathematics of the National Institute of Standards and Technology. The

reports in the series are as follows

.

1) The Internal Revenue Service Post-of-Dutv Location Modeling System:

Final Report

This report describes the post-of-duty location problem and its

mathematical model. It discusses the types of data which are considered

in calculating costs, describes the methods used to solve the location

problem, and gives a brief introduction to the computer implementation of

the model. (NIST Contact: Paul D. Domich)

2) The Internal Revenue Service Post-of-Dutv Location Modeling System:

User's Manual

This report is a user's guide for the post-of-duty location computer

system. It gives hardware and software requirements, instructions for

installing the system, descriptions of data files, and detailed

instructions for operating the system. (NIST Contact: Marjorie A.

McClain)

3)

The Internal Revenue Service Post-of-Dutv Location Modeling System:

Programmer's Manual for FORTRAN Driver

The post-of-duty location program is written in two sections of code, one

in FORTRAN and the other in PASCAL. This report describes the FORTRAN

driver which handles graphics displays and controls input and output for

the solution procedure. The report includes an alphabetical list of the

FORTRAN routines, describing the purpose, the calling sequence and the

variables of each routine. (NIST Contact: Marjorie A. McClain)

4)

The Internal Revenue Service Post-of-Dutv Location Modeling System:

Programmer's Manual for PASCAL Solver

This report describes the second part of the post-of-duty location

program, the PASCAL solver. It discusses the algorithms and data

structures used to solve a location problem. (NIST Contact: Paul D.

Domich)

1
B . Introduction to the System

The Internal Revenue Service Post-of-Duty Location System is a microcomputer package designed to assist IRS district planners in choosing

locations for posts-of-duty (POD's) which will minimize costs to the IRS and

to the taxpayer. The package uses color graphics in performing the

following functions.

1) Displaying Workload

The user may choose the type of workload to be displayed, such as the number of returns filed. Then a district zip code map is drawn,

with each zip code shaded according to the range of workload it

generates

2) Displaying Initial POD Sites

A district zip code map is drawn showing where POD's are currently

located and also where new POD's could potentially be located. The

user may make modifications to this information to specify POD's

which may not be or must be in the set of POD's determined by the

solution procedure.

3) Solving for Optimal POD Locations

Using the initial POD information specified by the user, the

solution procedure calculates the cost of assigning each zip code to

each current or potential POD. The cost includes travel costs

associated with the workload of each zip code, office rental costs,

and costs of opening new POD's or closing old POD's. The user may

set parameters indicating what types of workload (such as Examination or Collection) should be included in the travel cost

calculations. Also, weights may be assigned to pairs of zip codes

and POD sites to scale travel costs. The user must specify the

number of POD's desired in the solution. The solution procedure

then determines the set of POD's which will result in the least

total cost for the district.

4) Displaying Optimal POD Locations

A district zip code map is drawn showing where the new POD's

determined by the solution procedure are located. Also, a report

file may be generated which summarizes the problem specification and

the solution. The report includes a list of which zip codes are to

be assigned to which POD's, along with an estimate of staffing

requirements for each POD.

5) Controlling Display of Maps

On any of the district zip code maps mentioned above, the user may

zoom in on a small region, back up to a larger region, locate a specified zip code on the map, or find the zip code number of an area on the map.

2
The remaining sections of this manual describe how to set up and use

the POD location system. Section II contains the computer hardware and

software requirements. Section III explains the procedure for installing

the system and describes the format of required data files. Section IV

contains detailed instructions on how to operate the system.

C . User Assistance and Future Releases

Users should address any questions concerning the POD location system

to their regional representatives. The names of regional representatives

can be obtained by calling John Brown, National Office Facilities Management

(Space Management), at FTS 535-9870.

Future releases of the system, including updated workload and map data, are expected to be distributed annually in April or May. Distribution will

take place through the regional representatives

.

3
Section II: Computer Requirements

A. Hardware

The POD location system has been designed to run on an IBM-PC XT or AT

equipped with a math coprocessor and with one of the following types of

displays

1) IBM Enhanced Graphics Adapter with Enhanced Color Display (EGA')

This display has a screen size of 640x350 pixels and uses 16 colors.

Text, lines and marker symbols are drawn in high resolution, and

shaded regions of maps are filled using solid colors. The system

requires at least 128KB of graphics memory, rather than the standard

64KB. This extra graphics memory is necessary in order to display

16 distinct colors; without enough memory, colors which are different in the graphics program may look the same on the screen

(so, for example, a shaded map may appear to be all one color).

2) IBM Color Graphics Monitor Adapter (CGA)

This display, used in medium resolution mode, has a screen size of

320x200 pixels and uses four colors. Text characters are larger

than on the enhanced display, so menus take up a greater proportion

of the display screen. Shaded regions of maps are filled using

cross-hatching

The system requires 640KB of memory and approximately 1.5MB of disk space.

A printer is desirable, but not necessary.

The system may also run on IBM- compatible machines, but due to the use

of graphics device drivers (see Section III Part A) for the specific

displays listed above, unpredictable results may occur if other displays are used. The system has been successfully tested on a Compaq Deskpro 286 with

a Princeton Graphics Quadchrome monitor, on a Compaq portable, and on an IBM

PS/2 Model 60.

Note: Reference to a tradename or product in this report does not imply

endorsement by the National Institute of Standards and Technology.

B . Software

Users of the POD location system will be provided with all the required

executable code and graphics device drivers for the system. The only other

software requirement is IBM-PC DOS (Version 2.1 or later).

Programmers who want to be able to make changes in the system will need

additional software, such as source code, IBM Professional FORTRAN, Turbo

PASCAL, and the IBM Graphical Kernel System. See "The Internal Revenue

Service Post-of-Duty Location Modeling System: Programmer's Manual for

FORTRAN Driver" and "The Internal Revenue Service Post-of-Duty Location

Modeling System: Programmer's Manual for PASCAL Solver" for further details.

4
Section III: Setting Up the System

This section provides instructions for installing the POD location

system programs and data files on a PC hard disk. The instructions given

here are of a general nature applying to users in every district. More

explicit installation instructions specific to a given district may be

provided with the distribution disks. If so, such instructions override the

installation instructions in this manual.

A. Contents of the Distribution Disks

The following required files should be provided on the distribution

disks

.

1 . INIT VDI. EXE

2. VDIDY010 . SYS

3. VDIDY004 . SYS

4. VDI . SYS

5. LOCATE . BAT

6. DRIVER.EXE

7. SOLVER.COM

8. PODSITE.id

9. WORKLOAD . id

10. OUTLINE . id

11. ZIPCODE.id

12. CENTROID. id

The "id” extension in the last five file names should be replaced by the

two-digit district identification number. The following optional files

should also be provided on the distribution disks.

1. CONFIG.SYS

2. AUTOEXEC.BAT

3. DISTRICT

4. PONAMES . id

5. ADJACENT. id

The files INIT_VDI.EXE, VDIDY010 . SYS , VDIDY004 . SYS , and VDI . SYS are device driver files which link the graphics portion of the POD location

system to the type of display device being used (EGA or CGA) . The device

drivers are initialized in the CONFIG.SYS and AUTOEXEC.BAT files.

The files LOCATE . BAT , DRIVER. EXE , and SOLVER.COM contain the POD

location system programs. The batch file LOCATE.BAT calls DRIVER.EXE and

SOLVER.COM and is used to execute the system.

The files DISTRICT, PONAMES. id, PODSITE.id, WORKLOAD. id, OUTLINE. id,

ZIPCODE.id, CENTROID. id, and ADJACENT. id contain IRS data and geographic

data for a given district. These files are described more fully in Part C

of this section.

5
B . Installing the System

To install the POD location system on a PC hard disk, create a subdirectory for the system, make it the current directory, and copy the

contents of each distribution disk into the directory. The following

example of this process assumes that the system directory is called "POD"

(any other name may be substituted) and that the distribution disks are placed in the A drive.

C:

MD\POD

CD\POD

COPY A:*.* (Do this step for each distribution disk.)

To complete the installation process, it is necessary to initialize the

graphics device drivers in the CONFIG.SYS and AUTOEXEC.BAT files in the root

directory. These files contain commands which are loaded by the computer

when it is turned on. To install the CONFIG.SYS and AUTOEXEC.BAT files,

copy the sample CONFIG.SYS and AUTOEXEC.BAT files from the distribution

disks into the root directory, after making backup copies of any previously

existing CONFIG.SYS and AUTOEXEC.BAT files there. The sample files should

contain the following statements, assuming that the device drivers are in a subdirectory called "POD" and that the DOS file ANSI. SYS is in a subdirectory called "DOS".

CONFIG.SYS

BREAK ON

FILES=10

BUFFERS=10

DEVICE=C : \DOS\ANSI . SYS

DEVICE=C : \POD\VDIDY010 . SYS /G : CRT (for an EGA display)

DEVICE=C : \POD\VDIDY004 . SYS /G : CRT (for a CGA display)

DEVICE=C : \POD\VDI . SYS

AUTOEXEC . BAT

C : \POD\INIT_VDI

Some modifications to these statements may be necessary in order to

correctly specify directory names and other information to correspond to a particular computer configuration. After setting up the CONFIG.SYS and

AUTOEXEC.BAT files, restart the computer (by pressing <ctrl-alt-del>) for

the new files to take effect. This completes the installation process.

The following additional notes concerning the graphics device drivers,

CONFIG.SYS file, and AUTOEXEC.BAT file may be useful.

1) FILES=10 and BUFFERS=10 are values suggested by the Professional FORTRAN

manual for use with Professional FORTRAN programs. Larger values may be

substituted.

6
2) The file ANSI. SYS is provided with DOS, so its path name in the

CONFIG.SYS file should correspond to the user's DOS directory.

3) VDI.SYS must be the last device listed in the CONFIG.SYS file.

4) It is not actually necessary to include INIT_VDI in the AUTOEXEC.BAT

file. It may be executed at any time before running the POD location

system.

5) An EGA display can be made to emulate a CGA display by using the

VDIDY004.SYS device driver. Both device drivers can be listed together

in the CONFIG.SYS file; the one listed last will be the default display

mode used by the POD location system. To switch to the other device

driver, type SET DISPLAY=C :\POD\VDIDYxxx. SYS (where "xxx" is either "004" or "010") before running the program.

6) The DOS <shift-printscreen> command for making printed copies of a graphics screen will only work with the VDIDY004 device driver. It does

not copy EGA screens. (Type GRAPHICS before running the POD location

system if printed copies of graphics screens are desired; see the DOS

manual for more information.)

7) After making any changes to the CONFIG.SYS or AUTOEXEC.BAT files, the

computer must be restarted for the changes to take effect.

8) If the device drivers have not been properly initialized, the message

"CANNOT OPEN WORKSTATION" may appear when trying to run the POD location

system.

C . Description of Data Files

The remainder of this section describes the contents of the data files

required by the POD location system. It is not necessary to read this

material to be able to run the system, but it may be helpful in

understanding how the system works and in making modifications to the data.

Each data file has a descriptive name followed by a period and a twodigit extension representing the district office number. For example,

ZIPCODE.59 is the name of the file containing zip code boundary coordinates

for the Jacksonville District. In this manual, "id" is substituted for the

district office number.

The data files used by the POD location system can be divided into two

categories: (1) geographic data files used to draw maps and (2) IRS data

files used to initialize and solve a location problem. The geographic files

OUTLINE. id, ZIPCODE.id, and CENTROID. id are essential to the operation of

the system. They contain state outline coordinates, state zip code boundary

coordinates, and zip code centroid (geographic center) coordinates, all

stored in binary form. The remaining geographic files, DISTRICT,

ADJACENT. id, and PONAMES.id, are optional. The file DISTRICT contains only

the two-digit district office number; if the system does not find this file,

it asks the user for the district office number and then automatically

creates a DISTRICT file. The file ADJACENT. id contains zip code adjacency

7
information in binary form; it is used only for coloring the solution map

(see Section IV Part F) . The file PONAMES . id contains a list of state zip

code numbers and their corresponding post office names; this file is never

used by the POD location system but is provided for the user's information

Updates to the geographic data files will be provided annually as the post

office changes its zip codes. The user should not attempt to make any

alterations to these files.

Two IRS data files, PODSITE.id and WORKLOAD. id, are also essential to

the operation of the POD location system. The format of these files is as follows

PODSITE.id

The purpose of this file is to maintain a list of the zip codes and

associated costs of all POD sites which currently exist in the

district and also of any potential new POD sites. The first line of

the file should contain seven items

(1) the total number of possible POD sites (current and

potential) for the district,

(2) the office space requirement (given as square feet per TDITDA) ,

(3) the travel cost (dollars per mile)

(4) the travel distance limit (miles), i.e., the maximum one-way

distance that a person would be expected to travel between a zip code and a POD site,

(5) the number of Examination personnel for the district,

(6) the number of Collection personnel for the district, and

(7) the number of other personnel for the district.

Each remaining line of the file (one line per POD site) should contain

three items:

(1) the five-digit zip code of the site,

(2) the opening or closing cost for a POD at the site (dollars)

and

(3) the rental cost for office space at the site (dollars per

square foot per year)

To distinguish between current and potential POD sites, a minus sign

should be placed before the zip codes of current POD sites. This also

determines whether the second number is an opening or a closing

cost; current POD sites have closing costs and potential POD sites

have opening costs.

8
The following example of a PODSITE.id file shows nine POD sites, six

of which are current POD sites.

9 .590 .210 80. H

-20001 20000. 18.0

-20003 20000. 7.0

20004 150000. 9.5

20007 150000. 6.0

-20010 20000. 12.0

-20013 20000. 6.0

20014 150000. 3.5

-20015 20000. 14.0

-20018 20000. 12.0

Numbers in the file s

100 100

zip codes should be listed in sequential order.

The user should customize the PODSITE.id file for his or her own

district. Estimates should be made for opening/closing costs by zip

code in the user's district, as well for the office space costs, the

travel distance limit, and the staff totals. Most of the values in

the first line of the file can be changed interactively while running

the POD location system (see Section IV Part E) ; all other values must

be changed within the PODSITE.id file itself using a text editor such

as Wordstar.

WORKLOAD, id

The purpose of this file is to provide a list of all the zip codes in

the district with their annual workloads in each of 36 categories (see

below for category descriptions) . The beginning of the file provides

other related information:

Line 1 - The first line should contain a zero entry followed by the 36 IRS trip

factors, one for each category of workload. (An IRS trip factor is

the average number of trips an IRS employee must make for each case in

a particular category.) The user should revise this data for his or her own district.

Line 2 - The second line contains a zero entry followed by the 36 taxpayer trip

factors (the average number of trips a taxpayer must make per case)

.

The user should revise this data for his or her own district.

Line 3 - The third line contains a zero entry followed by the 36 staffing

factors (the relative amount of time required to process a case in

each workload category) . This data was developed by the National

Office but may be changed if the user desires.

9
Each remaining line of the file (one line per zip code, listed in

sequential order) should contain a five-digit zip code followed by 36

numbers giving the workload for that zip code in each of the following

categories

1) BMF Exam - TY85 1120 Returns above "Optimal" DIF Score

- No Balance Sheet

2) BMF Exam - TY85 1120 Returns above "Optimal" DIF Score

- < $100,000

3) BMF Exam - TY85 1120 Returns above "Optimal" DIF Score

- $100,000 to $1M

4) BMF Exam - TY85 1120 Returns above "Optimal" DIF Score

- $1M to $10M

5) BMF Exam - TY85 1120 Returns above "Optimal" DIF Score

- > $10M

6) BMF Exam - TY85 1120S Returns Filed - < $100,000

7) BMF Exam - TY85 1120S Returns Filed - $100,000 to $1M

8) BMF Exam - TY85 1120S Returns Filed - $1M to $10M

9) BMF Exam - TY85 1120S Returns Filed -• > $10M

10) BMF Exam - TY85 1065 Forms Filed

11) BMF Exam - TY85 720 Forms Filed

12) BMF Exam - TY85 706 Forms Filed

13) BMF Exam - TY85 2290 Forms Filed

14) BMF Exam - TY85 730 Forms Filed

15) IMF Exam - TY85 Returns above "Optimal" DIF Score - Class 1

16) IMF Exam - TY85 Returns above "Optimal" DIF Score - Class 2

17) IMF Exam - TY85 Returns above "Optimal" DIF Score - Class 3 18) IMF Exam - TY85 Returns above "Optimal" DIF Score - Class 4

19) IMF Exam - TY85 Returns above "Optimal" DIF Score - Class 5 20) IMF Exam - TY85 Returns above "Optimal" DIF Score - Class 6 21) IMF Exam - TY85 Returns above "Optimal" DIF Score - Class 7 22) IMF Exam - TY85 Returns above "Optimal" DIF Score - Class 8 23) IMF Exam - TY85 Returns above "Optimal" DIF Score - Class 9

24) IMF Exam - TY85 Returns above "Optimal" DIF Score - Class 10

25) IMF Exam - TY85 Returns above "Optimal" DIF Score - Class 11

26) IMF Exam - TY85 Returns above "Optimal" DIF Score - Class 12

27) BMF Collection - Modules with Active TDI in CY87

28) BMF Collection - Modules with Active TDA in CY87

29) IMF Collection - Modules with Active TDI in CY87

30) IMF Collection - Modules with Active TDA in CY87

31) IMF Returns Filed in CY87

32) BMF Returns Filed in CY87

33) IMF Exams Closed in CY87

34) BMF Exams Closed in CY87

35) TDI's Issued in CY87

36) TDA's Issued in CY87

10
Only the first thirty workload data types are used by the POD location

system to choose the best POD sites. Optimal rather than existing workload

is used since existing workload is often a function of the current location

of POD's and staff rather than the optimal location. The remaining six data

types (31-36) are used only in the workload display section of the system

(see Section IV Part C) for the user's information. Consequently, the trip

factors and staffing factors corresponding to these data types can be set to

zero (or any number) since they will have no effect on the output of the

system.

It is permissible for the user to change the numbers in the WORKLOAD. id

file, as long as the file format remains as described above. However, the

user should not attempt to add or delete zip codes from the workload file,

since this may invalidate information in the geographic file ADJACENT. id.

Updates to the WORKLOAD. id file will be provided annually, based on data for

the prior calendar year.

To summarize, the following data files must exist to run the POD

location system.

1) OUTLINE

.

id

2) ZIPCODE. id

3) CENTROID . id

4) PODSITE. id

5) WORKLOAD .id

(state outline file)

(zip code boundary file)

(centroid file)

(POD file)

(workload file)

11
Section IV: Using the System

A . Overview

This introduction gives a general overview of the steps a user should

go through to solve a location problem. Detailed instructions for each step are provided in later parts of this section. The overview also describes

how maps are used in the system and explains how to use the cursor to locate

zip codes and to zoom in on maps.

Steps in Solving a Location Problem

(Before the system is used for the first time, it must be properly

installed. In particular, graphics device drivers must be initialized in

the user's CONFIG.SYS and AUTOEXEC.BAT files. See Section III Part B for

information on how to do this.)

1) Enter the system.

Type LOCATE to enter the system. If requested, type in the district

number. Wait for the top-level menu to appear. (See Part B for more

information on entering the system.)

2) Display workload.

This step may be repeated at any time, or it may be skipped. Select the

function for displaying workload from the top menu. Choose the category

of workload to be displayed. A state map will appear which can be zoomed

in on to show zip codes shaded according to their workloads. (See Part C

for more information on displaying workload.)

3) Display and initialize POD information.

This step is optional. From the top menu, select the function for

displaying and modifying initial POD sites. A state map will appear with

asterisks showing where POD's are currently located. Zoom in on the map

to an area of interest, and then color in zip codes to indicate whether

they are to be considered as currently existing POD sites, potential new

POD sites, or fixed POD sites which cannot be moved. Zip codes which are not colored will not be considered as possible POD sites. (See Part D

for more information on displaying POD information.)

4) Solve for best POD locations.

From the top menu, select the function for solving for optimal POD

locations. Set options as requested to select categories of workload to

be considered in the cost calculation and to choose weights for IRS and

taxpayer costs. Travel difficulty factors may be entered for pairs of

zip codes and POD sites which are separated by geographic barriers.

Choose the number of POD's desired in the solution. The solution

procedure will then begin, and a summary of the stages of the process

12
will appear on the screen. (See Part E for more information on

and solving a location problem.)

5) Display solution.

This step is optional. Select the function for displaying optimal POD

locations from the top menu. A state map will appear with asterisks

showing where POD's have been placed by the solution procedure. Zoom in

on the map to areas of interest. (See Part F for more information on displaying a solution.)

6) Generate report file.

From the top menu, select the function for reporting zip code and staff

assignments. This option creates a report file which contains a complete

summary of the current POD location problem. For each POD in the

solution, the report lists all the zip codes which should be assigned to

it, along with an estimate of the staff required for its workload. The

report file may be printed out when exiting from the system. (See Part G

for more information on the report file.)

7) Exit from the system.

From the top menu, select the function for exiting from the system.

Print out the report file, or examine it with an editor such as Wordstar.

(See Part H for more information on exiting from the system.)

Use of Maps

In several of the steps listed above, maps are drawn to display

information. Although the type of information is different at each step,

the procedure for manipulating the maps is the same. The user may zoom in on a small region, back up to a previous map, locate a specified zip code

number, or find the zip code number of a specified area on the map.

The first map drawn always shows the outline of the state and centroids

(geographic centers) of selected zip codes, but no zip code boundaries.

(The reason for not including zip code boundaries at this level is that many

of them would be too small to be distinguished and it would take a very long

time to draw them for the whole state.) A menu appears to the left of the

map giving the user several choices on how to proceed.

1) Exit

This option returns the user to the top menu.

2 ) Zoom

This option allows the user to zoom in on the map to display zip code

boundaries in a small region. When this option is chosen, instructions

appear in the menu area telling how to use the cursor to draw a box

around the area to be enlarged. First a crosshair (+) cursor appears in

the center of the screen, which can be moved using the arrow keys and the

13
"home", "end", "page up" and "page down" keys on the right side of the

keyboard (or with a mouse) . (If the cursor keys do not work, check to be

sure the "num lock" key is off.) Move the cursor to one corner of the

area to be enlarged; then press return (f—*) to enter the coordinates of

this point into the computer. (The cursor can move in either large or small increments. Pressing the "insert" key toggles between the two

modes.) Next, move the cursor to locate the diagonally opposite corner

of the box. This time the box is actually drawn on the screen. Then

press return (<—*) to enter this point.

The old map will be erased from the screen, and a new map showing zip

codes in the boxed area will be drawn. A new menu will appear on the

left side (see below) . If a mistake was made in entering the box

corners (for example, if both corners were the same point), the message

"ZOOM ERROR: DO YOU WANT TO TRY AGAIN?" will appear. If the answer is

"yes", the user may start over, again entering diagonal corners of the

box. If the answer is "no", the previous menu reappears on the screen.

3) Mark Zip Code

When this option is chosen, the user is asked to type in a zip code

number. If the zip code exists, its location will be marked by an "X" on

the state map. Otherwise, the message "NOT FOUND" will appear. This

option is available only for the full state map. The "X" disappears when

the user zooms in on the map.

After the second option above (Zoom) is chosen, a new menu appears on

the left side of the screen with the following options.

1) Exit

This option returns the user to the top menu.

2 ) Zoom

This option allows the user to zoom in on a specified area of the current

map. The procedure for drawing a box around the area is the same as given above. After the new map has been drawn, the same menu of options

appears. The user may zoom as many times as desired.

3 ) Back Up

This option redraws the previous map and its display menu. Only one level of backing up is allowed. For example, if five zooms had been

done, only the fourth map could be redisplayed. However, it is always

possible to return to the state outline map and then zoom in again.

4) Full State

This option redraws the state outline map with zip code centroids.
5 ) Map Key

This option displays a key which defines the colors on the map. Two

further options are available at this level. First, the user may exit

from the map key and return to the menu of display options. Second, the

user may move the cursor to locate a zip code region on the map and have

its five -digit number displayed in the lower left corner of the screen.

The cursor is moved with the arrow keys and the "home", "end", "page up"

and "page down" keys on the right side of the keyboard (or with a mouse)

.

Pressing the "insert" key makes the cursor toggle between large and small

increments. To locate a zip code, move the cursor near the centroid of

the zip code and press return (4—*) . The five-digit zip code number will

be written at the bottom of the menu area. If the cursor is too far away

from a centroid, the message "ZIP NOT FOUND" will be written instead.

It is important to keep in mind that the system does not recognize the

boundary lines on the map, so it is not necessarily enough merely to have

the cursor in the correct zip code region. The cursor must be positioned

close to the centroid of the region of interest. The zip code printed is

that of the nearest centroid to the cursor, whether it is in the same region as the cursor or not.

(Note: Occasionally, instead of a zip code number the message "ZEROZIP"

appears. This occurs for areas which have no official zip codes.)

In addition to the two options discussed above, other options are available on this menu for the POD initialization map to change the

colors of zip codes. See Part D for information on how to do this.

The

detailed

remainder of

instructions

this report provides descriptions of menus and

for each step used in solving a POD location problem.

15
B . Entering the System

To enter the POD location system, switch to the directory containing

the system files (using the DOS "Change Directory" command) and type LOCATE.

A title page will appear on the screen. (If, instead, an error message

"4001" appears and the program begins to cycle erratically, probably the

computer does not have a math coprocessor. See Section II Part A for

hardware requirements.) Then, if prompted, enter the two-digit district

office identification number. (This number must be the same as the twocharacter extension for each of the system data file names. See Section III

Part A.) The district number should only need to be entered the first time

the system is used. It is then saved in a file called DISTRICT for

automatic use in subsequent sessions. (The DISTRICT file should be provided

on the distribution disks, in which case the district number prompt will

never occur.)

If a report file exists from a previous session, the system will then

ask whether the report is to be overwritten. (See Parts G and H for

information on the report file.) If the user answers "yes", the old report

file will be replaced by a new report on the current session. If the user

answers "no", the new report will be appended to the old report file.

The message "Working ..." will then appear, followed by a brief pause.

(If the pause lasts for more than a minute or if the message "CANNOT OPEN

WORKSTATION" appears, check for device driver errors in the AUTOEXEC.BAT or CONFIG.SYS files. See Section III Part B.) Then the top-level menu will

appear on the screen, as shown in Figure 1.

IRS POST-OF-DUTY LOCATION SYSTEM

FI - Exit.

F2 - Display workload.

F3 - Display or modify initial POD sites.

F4 - Solve for optimal POD locations.

F5 - Display optimal POD locations.

F6 - Report zip code and staff assignments.

Figure 1. Top-level menu.

16
This menu lists the steps used to solve a POD location problem, along with a function key number for each step. To make a selection from the menu, just

push the corresponding function key (no return (<—') is necessary) . The

following is a brief description of each of the choices in the top menu. For a more complete description, see the subsection listed in parentheses.

FI - Exit (Part H)

Exits from the POD location system.

F2 - Display workload (Part C)

Draws a map showing workload for each zip code.

F3 - Display or modify initial POD sites (Part D)

Draws a map showing where POD's are currently located and also where

new POD's are allowed to go. The user may alter this information by

coloring the map, and the data is saved for use by the solution

algorithm (see F4)

.

F4 - Solve for optimal POD locations (Part E)

Solves the location problem initialized using F3

.

F5 - Display optimal POD locations (Part F)

Draws a map showing the new POD locations determined using F4.

F6 - Report zip code and staff assignments (Part G)

Generates a report file which summarizes the input data and the

solution to the current location problem.

17
C . Displaying Workload

The F2 function in the top menu is used to display a map showing

workload for each zip code in the district. Before drawing the map, the

system will ask the user to choose the category of workload to be displayed

from the following list.

1) Examination

2) Collection

3) A single column of the workload file

4) A user- specified combination of columns

Type the number of the desired category. If category 1 is selected, total

"optimal" Exam workload (columns 1-26 from the file WORKLOAD. id) will be

displayed. (See Section III Part C for a description of individual workload

columns.) If category 2 is selected, total Collection workload (columns 27-

30) will be displayed. If category 3 is selected, the user will be prompted

to type in the number of the column to be displayed (a number from 1 to 36) . If category 4 is selected, a horizontal list of column numbers will appear.

The user should type a "1" under each column to include. The workloads in

these columns will be added together for the display, so the user should

take care that the columns chosen are compatible. That is, it does not make sense to add BMF returns to IMF TDI ' s , for example.

The workloads for each zip code are then read in from the file

WORKLOAD. id. While the file is being read, the system compares the zip

codes in the workload file with the zip codes in the master zip code list.

(The master list consists of all the zip codes in the boundary file, which

will be used to draw the map.) If any zip codes appear in the workload file

but not in the master list, they will be ignored. If any zip codes appear

in the master list but not in the workload file, they will be drawn as blank

areas on the workload map. (In particular, zip codes from other districts

in the same state will be drawn as blank areas.)

Next, the system must decide what color to associate with each workload

value. By default, it looks at the minimum and maximum workload which it

read from the file, divides this span into six equal ranges, and lists the

ranges on the screen, as in the following example.

NUMBER OF RANGES: 6

LOWER LIMIT OF RANGE #1: 0

UPPER LIMIT OF RANGE #1: 11

UPPER LIMIT OF RANGE #2: 22

UPPER LIMIT OF RANGE #3: 34

UPPER LIMIT OF RANGE #4: 45

UPPER LIMIT OF RANGE #5: 56

UPPER LIMIT OF RANGE #6: 68

In this example, the system would assign one color to zip codes with

workloads between 0 and 11, a second color to those between 11 and 22, a third color to those between 22 and 34, and so on, for a total of six

colors. However, before proceeding with this, the system asks if the user

wishes to change these range assignments. If so, it next asks how many

ranges (colors) are desired, which may be any number from 2 through 6. The

18
system lists the new equally- spaced ranges on the screen. The user may then

proceed to change the range limits , by entering each range in order when

prompted. (Note that the user may not change the lower limit of the first

range or the upper limit of the last range, since these values are determined by the actual minimum and maximum workload read from the data

file.) Once the user has entered acceptable workload ranges, the system

proceeds to assign a color to each zip code in the district according to

which range its workload lies in.

After the workload file has been read and colors have been calculated,

a map showing only the state outline and small boxes for zip code centroids

is drawn. Centroids are drawn only for zip codes which appear in the

workload file. No zip code boundaries are drawn at this level. On an EGA display, the centroids are drawn in six different colors, with brighter

colors indicating higher workloads. On a CGA display, all the centroids are drawn in yellow; the user must zoom in on the map in order to see the

workload. To the left of the state map, a menu of display options appears

on the screen (see Figure 2).

19
Figure 2. Full state map display menu.

The menu choices are discussed below.

FI - Exit

Exits from the workload map. The user is then given the option of

redisplaying the map with different range limits. (This may be

desirable if, for example, the user notices that most of the zip codes

fall into only one or two of the original ranges.) Otherwise, the

system exits from the workload display mode and returns to the top menu.

F2 - Zoom

Zooms in on a specified area of the map to display workload there. See

Part A for a complete description of how to use the cursor to draw a box around the area. A new map showing zip code boundaries in the

boxed area will be drawn, and a new menu will appear (see below).

F3 - Mark Zip Code

Allows the user to type in a zip code number and have its location

marked on the map. See Part A for more information.

After choosing F2 from the full state display menu, the menu of display

options shown in Figure 3 will appear.

20
Figure 3. Zip code map display menu.

The options are described below.

FI - Exit

Exits from the workload map. The user is then given the option of

redisplaying the map with different range limits. (This may be

desirable if, for example, the user notices that most of the zip codes

fall into only one or two of the original ranges.) Otherwise, the

system exits from the workload display mode and returns to the top menu.

F2 - Zoom

Zooms in on a specified area of the current map. See Part A for a complete description of how to use the cursor to draw a box around the area. After the new map has been drawn, the same menu of display

options appears. The user may zoom as many times as desired.

F3 - Back Up

Redraws the previous map and its display menu. Only one level of

backing up is allowed.

F4 - Full State

Redraws the state outline map with zip code centroids. The full state

display menu also reappears.

F5 - Hap Key

Displays the map key shown in Figure 4 defining what the zip code

colors mean.

21
Figure 4. Workload key.

There is a color for each of the possible workload ranges, listed

in order from the lowest workload to the highest workload. The number

written in each color bar is the upper limit of the workload range

represented by that color. Two menu options exist.

FI - Exits from the workload key and returns to the menu of display

options

F2 - Allows the user to find the zip code number of an area on the map

located by the cursor. The zip code number is displayed in the

lower left corner of the screen. (The procedure for using the

cursor to locate a zip code is described in Part A.)

22
D . Displaying or Modifying Initial POD Sites

The F3 function in the top menu is used to display a map showing

current POD sites and other potential POD sites in the district. This

information is read from the file PODSITE.id. The user is allowed to make

modifications by changing the colors on the map. The modified POD

information is saved for use later by the solution algorithm.

Before the map is drawn, the system checks to see that all POD zip

codes appear in the master list of zip codes obtained from the boundary

file. If any mismatches occur, a message will appear on the screen and the

POD will be ignored by the system. The user should check on the accuracy of

the file PODSITE.id.

After the zip codes have been checked, a map showing only the state

outline and centroids of certain zip codes is drawn. On an EGA display,

centroids of current POD sites are drawn as red asterisks and centroids of

other potential POD sites are drawn as small blue boxes; other zip code

centroids are not drawn. On a CGA display, centroids of current POD sites

are drawn as red asterisks and centroids of potential POD sites are drawn as yellow boxes. A menu of display options appears on the left side of the

screen (see Figure 5)

.
Figure 5. Full state map display menu.

The menu choices are discussed below.

FI - Exit

Exits from the POD initialization mode and returns to the top menu. The current POD set-up is saved to be used later by the solution

algorithm.

F2 - Zoom

Zooms in on a specified area of the map to display POD information

there. See Part A for a complete description of how to use the cursor

to draw a box around the area. A new map showing zip code boundaries

in the boxed area will be drawn, and a new menu will appear (see

below)

F3 - Mark Zip Code

Allows the user to type in a zip code number and have its location

marked on the map. See Part A for more information.

After choosing F2 from the full state display menu, the menu of display

options shown in Figure 6 will appear.

24
The options are described below.

FI - Exit

Exits from the POD initialization mode and returns to the top menu. The current POD set-up is saved to be used later by the solution

algorithm.

F2 - Zoom

Zooms in on a specified area of the current map. See Part A for a complete description of how to use the cursor to draw a box around the area. The same menu will appear after the new map is drawn, and the

user may zoom as many times as desired.

F3 - Back Up

Redraws the previous map and its display menu. Only one level of

backing up is allowed.

F4 - Full State

Redraws the state outline map with zip code centroids. The full state

display menu also reappears.

F5 - Map Key

Displays the map key shown in Figure 7 defining what the zip code

colors mean.

25
Figure 7. POD map key.

A function key is associated with each color to allow colors to be

changed on the map. The functions are as follows.

FI - Exits from the map key and returns to the menu of display options

F2 - Allows the user to find the zip code number of an area on the map

located by the cursor. The zip code number is displayed in the

lower left corner of the screen. (The procedure for using the

cursor to locate a zip code is described in Part A.)

F3 - Enters the mode for changing the color of a zip code on the map.

The zip code must have been located already using F2.

F4 - Sets a zip code to be a site which is not allowed to have a POD.

The coloring mode must have been entered using F3

F5 - Sets a zip code to be a site which is allowed to have a POD but

does not currently have one. The coloring mode must have been

entered using F3

F6 - Sets a zip code to be a site which currently has a POD. The

coloring mode must have been entered using F3 . Current POD sites

are allowed to be removed by the solution algorithm.

F7 - S ets a zip code to be a site which must have a POD. The coloring

mode must have been entered using F3 . Sites which must have a POD are fixed and will not be removed by the solution algorithm.

To summarize, the map originally shows current POD sites and other

potential POD sites as read from the file PODSITE.id. The user may fix

26
a POD site or make other changes by first locating the zip code with

the cursor (F2)

,

entering the coloring mode (F3)

,

and then choosing the

correct color (F4, F5 , F6 or F7). A message is always given at the

bottom of the menu area telling which functions keys can currently be

used; if any other key is pushed it will be ignored.

27
E . Solving for Optimal POD Locations

The F4 function in the top menu is used to solve a POD location problem

given an initial configuration of current, potential and fixed POD sites, as set up using the F3 function. (If F3 was not done first, the solution

proceeds using the initial configuration given in the file PODSITE.id.) If

the system detects any POD sites for which it does not have opening/closing

costs or office rental costs, the user will be prompted to enter this

information.

After F4 is pushed, the system will allow the user to set various

parameters to be used in calculating costs. A list of default parameter

settings will appear on the screen, similar to the following.

# ITEM POSSIBLE ACTUAL

1 IMF EXAMINATION 0 OR 1 | 1

2 IMF COLLECTION 0 OR 1 | 1

3 BMF EXAMINATION 0 OR 1 1

4 BMF COLLECTION 0 OR 1 | 1

1 - INCLUDED IN COST CALCULATION, 0 = NOT INCLUDED

5 TAXPAYER TRAVEL COST WEIGHT | 1.000

6 IRS TRAVEL COST WEIGHT 1 . 000

7 MAXIMUM TRAVEL DISTANCE i 80.000

8 OFFICE SPACE REQUIREMENT |! 0.590

9 DOLLAR COST PER MILE TRAVELED | 0.210

10 TOTAL AVAILABLE EXAMINATION STAFF | 100

11 TOTAL AVAILABLE COLLECTION STAFF i 100

12 TOTAL AVAILABLE OTHER STAFF i 100

The first four items indicate which categories of workload should be

included in the cost calculation; a value of 1 means the category is

included and a value of 0 means it is not included. The next two items are weights to be assigned to IRS employee travel costs and taxpayer travel

costs. For example, setting the IRS weight to 0 and the taxpayer weight to

1 would cause the solution procedure to consider only costs to the taxpayer.

The weights can have any nonnegative decimal value. The seventh item on the

parameter list is the maximum distance that a person would be expected to

travel between a zip code and a POD. The value listed (in this example, 80

miles) is read from the file PODSITE.id. The distance limit has the effect

of cutting down on storage space and on the running time of the solution

procedure, since zip codes and POD sites separated by too large a distance

can be eliminated from consideration. The eighth item is the office space

requirement, given as square feet per TDI-TDA. The ninth item is the travel

cost (dollars per mile), and the final three items give the number of Exam,

Collection, and other staff people available for assignment to the POD's in

the district.

The user should carefully review the parameter settings to determine

whether they correctly reflect the situation in the user's district. The

system will then ask whether the user wishes to change any of the default

parameter settings. If the answer is "yes", the user is asked to enter the

28
number of the item to be changed and its new value. These should be typed

on one line, separated by a space. The new value will then appear in the

parameter list, and the user may proceed to make further changes. Changes

to parameters 7-12 may be made permanent when exiting from the system. (See

Section H for more information.)

Next, the system will ask if the user wants to change any travel

difficulty factors. These are weights which are assigned to pairs of zip

codes and POD's to scale their travel costs. This is especially useful in

cases where, for example, a zip code and a POD site are close together (in

terms of the distance between their centroids) but are separated by some geographic barrier (such as a bay or mountain range) which makes travel

between them difficult. By assigning a high weight to the pair, the user

makes it unlikely that the solution procedure will try to assign the zip

code and POD to each other. It should be kept in mind that the solution

procedure automatically takes distances between zip codes and POD's into

account when making assignments, so distance should not be considered when

setting difficulty factors. This option basically converts the distance

between centroids to actual travel milage.

Default settings for travel difficulty factors are read from the file

DIFFACT.id if it exists; otherwise all factors are assumed to be equal to one. If the user responds "yes" to the question on changing travel

difficulty factors, new values may be entered into the file. Type a zip

code, a POD zip code and the new factor on one line separated by spaces.

The factor may be any positive number. A factor greater than one implies

that travel is of more than average difficulty; a factor less than one implies easier travel.

After travel difficulty factors have been set, the system prepares to

begin the solution process. Before proceeding, however, the user is given

the opportunity to abort the solution process and return to the top menu by

pressing Q. This should be done if the user realizes that some parameter

may have been incorrectly specified. Otherwise, by pressing any key other

than Q, the solution process will begin. There will be a pause for several

minutes while the workload file WORKLOAD. id is read and all possible zip

code pairs and their costs are computed. (For a complete mathematical

description of the cost calculation, see "The Internal Revenue Service Postof-Duty Location Modeling System: Final Report".) The zip codes in the

workload file are compared with the master list of zip codes obtained from

the boundary file. If any zip codes appear in one file but not the other,

they are eliminated from consideration by the solution procedure.

It is possible that for some zip code there may be no POD site within

the required distance limit. In this case, the solution cannot proceed and

an error message will appear on the screen. The user should then either

increase the distance limit or set additional potential POD sites.

After costs for each zip code pair have been calculated, a summary is

printed giving the total number of zip codes, the total number of possible

POD sites (current and potential), and the number of initial POD's (current

and fixed). Then the user is prompted to enter the number of POD's desired

in the solution. This can be any number from one to the total number of

possible POD sites.

29
The solution computation then begins and passes through four phases,

which are outlined below. However, it is not necessary for the average user

to understand these phases.

1 ) Initial Assignment

Zip codes are assigned to the initial set of POD's, and the total cost of

the assignment is printed on the screen.

2) Initial Interchange

Each initial POD is examined to see if it can be interchanged with

another potential site to give a lower allocation cost. A message is

printed on the screen whenever an interchange is made. The result at the

end of this phase is a better arrangement of the initial number of POD's.

The cost of the new arrangement is printed on the screen.

3) Greedy Heuristic

In this phase, POD's are added to (or deleted from) the previous set

until the specified number of POD's has been reached. One POD is added

(or deleted) at a time, and it is chosen as the site which, when taken

with the previous set, will give the lowest possible allocation cost.

Messages are printed on the screen telling which POD's have been added

(or deleted) and what the allocation cost is at each step.

At some stage of the solution algorithm, a message may appear saying that

a solution is infeasible. This means that for some zip code it was impossible to find a POD site within the specified maximum distance

limit. The algorithm will proceed using the last known feasible number

of POD's for the final interchange.

4) Final Interchange

In the last phase, the set of POD's determined by the greedy heuristic is

examined to see if any POD in the set should be interchanged with one not

in the set. The interchanges are listed on the screen along with the

final allocation cost.

There is a fifth optional step to the solution process. The system will ask

whether lower bounds should be produced to the optimal solution. If the

answer is "yes”, the system will attempt to obtain a measure of how good the

solution is. The greedy and interchange methods are heuristics, that is,

they will find very good locations for the POD sites but not necessarily the

absolutely best locations. The lower bound procedure calculates an estimate

of how close the greedy- interchange solution is to the true best solution.

In the course of doing this, the procedure may come across a better solution

than the greedy- interchange solution. If so, the greedy- interchange

solution is replaced by the new solution.

Colors are then calculated for the solution map, to be displayed later,

and the top menu reappears on the screen. At this point, if the user wishes

to solve the same problem again with a new number of POD sites, he or she

should enter F4 again without doing F3 first. The system will detect that

30
no new POD initialization was set up and will proceed directly to the

solution phase without recalculating all the zip code assignment costs.

This allows the same problem to be solved quickly for different numbers of

POD sites.

Note: The cost figures produced by the solution procedure are not "real"

costs; they are an estimate of the travel cost of working all "optimal"

workload (see Section III Part C) , as well as the office space and

opening/closing costs. These costs are used within the POD location system

to compare possible solutions and should not be used outside of the system.

The user should also remember that factors other than travel, space, and

opening/closing costs should be considered when choosing a POD location,

such as the availability of labor and the existence of Economic Development

Areas. The user should discuss questions in this area with National Office

Facilities Management.

31
F . Displaying Optimal POD Locations

The F5 function in the top menu is used to display a map showing the

solution to the POD location problem determined using the F4 function.

First a map of the state outline is drawn, with asterisks indicating the

centroids of POD's in the solution. The menu of display options shown in

Figure 8 appears on the left side of the screen.
Figure 8. Full state map display menu.

The menu choices are discussed below.

FI - Exit

Exits from the solution display mode and returns to the top menu.

F2 - Zoom

Zooms in on a specified area of the map to display the solution there.

See Part A for a complete description of how to use the cursor to draw

a box around the area. A new map showing zip code boundaries in the

boxed area will be drawn, and a new menu will appear (see below)

.

F3 - Mark Zip Code

Allows the user to type in a zip code number and have its location

marked on the map. See Part A for more information.

After choosing F2 from the full state display menu, the menu of display

options shown in Figure 9 will appear.

33
DISPLAY

DPT I OHS

Fl- EXIT

F2- ZOCM

F3- BACX UP F4-FULL

STATE

FSflftP KEY

Figure 9. Zip code map display menu.

The options are described below.

FI - Exit

Exits from the solution display mode and returns to the top menu.

F2 - Zoom

Zooms in on a specified area of the current map. See Part A for a complete description of how to use the cursor to draw a box around the area. The same menu will appear after the new map is drawn, and the

user may zoom as many times as desired.

F3 - Back Up

Redraws the previous map and its display menu. Only one level of

backing up is allowed.

F4 - Full State

Redraws the state outline map with zip code centroids. The full state

display menu also reappears.

F5 - Map Key

Displays the map key shown in Figure 10.

34
NEU

PODS

Fl-EXir

F2-F IHD ZIFCODE

* = POD

USE

F1-F2

Figure 10. Solution map key.

Zip codes which the solution algorithm determined should be POD sites

are marked by asterisks on the map. The solution map will show a POD

site and its assigned zip codes all drawn in the same color. (Note: If

the file ADJACENT. id was missing from the distribution disks, this map

will show only POD sites, with no zip code assignments.) The following

options exist on the menu.

FI - Exits from the solution key and returns to the menu of display

options

.

F2 - Allows the user to find the zip code number of an area on the map

located by the cursor. The zip code number is displayed in the

lower left corner of the screen. (The procedure for using the

cursor to locate a zip code is described in Part A.)

35
G . Reporting Zip Code and Staff Assignments

The F6 function in the top menu is used to generate a solution report

in the file REPORT. id. This file contains a complete summary of the current

session. The report does not appear on the screen, but it may be printed

out upon exiting from the system or it may be examined later with a text

editor such as Wordstar.

The file always contains the date and time of the beginning of the

session and a summary of any input data which was used, including initial

POD sites and their costs, user options, trip factors and staffing factors.

This information is included in the report file even if the user never

chooses the F6 function. When F6 is chosen, a section is added to the

report which lists each POD in the solution, along with its assigned zip

codes, its workload totals, and its prorated share of Exam, Collection and

other total staffing. It should be kept in mind that the purpose of the POD

location system is to choose optimal locations for POD's in a district, not

to find optimal staffing assignments, so the staff numbers reported are only

estimates. The estimates are based on spreading the total available staff

for the district according to the workload of each POD's zip codes. (Note:

If the system assigns more staff to a POD than is physically possible under

current space constraints , this indicates the need for an additional POD in

that general area.)

36
H . Exiting from the System

To exit from the POD location system, choose FI from the top menu. The

system will automatically delete several work files which were created

during the session. For reference, the names of these files are ERRORS. GKS,

TRANSFER. id and SOLUTION. id.

If, during the course of solving a location problem, the user altered

any POD site information or any parameters such as the distance limit or the

staff totals, the system will ask before terminating whether these changes

should be made permanent. If not, the changes will be lost. However,

making permanent changes should be done with great caution, since the

original PODSITE.id file will be overwritten.

Next, if a printer is attached, the system will ask if the report file

should be printed out. This file contains a complete summary of all data

used and all activities performed during the current session. (Reports of

previous sessions may also be contained in the same file.) If the user does

not choose to print the report, the information is still available in a file

called REPORT. id. The file may be printed out later or examined with a text

editor such as Wordstar.

Note: If the user asks to have the report printed out and instead the

message "Bad command" appears, the user's computer probably does not have a path set up for DOS files, so the system could not find the "Print" command.

The user should find the directory containing the DOS files and then create

a path to this directory (see the DOS manaul for more information)

.

37
INDEX

A

ADJACENT. id file 5, 7-8, 11, 35

ANSI. SYS 6, 7 AUTOEXEC.BAT 5, 6, 7, 12, 16

B

Back up (to previous map) 2, 14, 21, 25, 34

Boundary file,

state 5, 7, 11

zip code 5, 7, 11, 18, 23, 29

BUFFERS statement 6

C

Centroid 5, 7, 11, 13, 15, 19, 23, 29, 32

CENTROID. id file 5, 7, 11

CGA 4, 5, 6, 7, 19, 23

Closing costs 2, 8, 9, 31

Color graphics monitor adapter 4, 5, 6, 7, 19, 23

CONFIG.SYS 5, 6, 7, 12, 16

Coprocessor 4, 16

Cost options 2, 12, 28, 29, 36

Current POD sites 2, 8, 9, 12, 17, 23, 26, 28, 29

Cursor 13, 14, 15

D

Data files 3, 7-11

Device driver 4, 5, 6, 7, 12, 16

DEVICE statement 6, 7 DIFFACT . id file 29

Difficulty factors 2, 12, 29

Distance limit 8, 9, 28, 29

Distribution disks 5 DISTRICT file 5, 7, 16

DOS 4, 6, 7, 37

DRIVER . EXE 5

E

EGA 4, 5, 6, 7, 19, 23

Enhanced color display 4, 5, 6, 7, 19, 23

Enhanced graphics adapter 4, 5, 6, 7, 19, 23

Entering the system 12, 16

ERRORS. GKS 37

Exiting from the system 13, 17, 37

F

File name format 5 , 7

FILES statement 6

Final interchange 30

Find zip code with cursor 15, 22, 26, 35

Fixed POD sites 2, 12, 26, 28, 29

FORTRAN 1, 4, 6

Full state map display menu 13, 14, 20, 24, 33

38
Function keys , use of 17

G

Geographic data files 3, 5, 7, 8, 11

GKS 4

Greedy heuristic 30

Graphical Kernel System 4

H

Hardware requirements 4

IInfeasible solution 29, 30

INIT_VDI.EXE 5, 6, 7

Initial assignment 30

Initial interchange 30

Installation 5-7

Interchange heuristic 30

IRS data files 5, 7, 8-11

IRS travel cost weight 12, 28

L

LOCATE . BAT 5

Lower bound procedure 30

M

Map key,

POD types 26

solution 35

workload 22

Map options 13-15

Mark zip code on state map 14, 20, 24, 33

Master zip code list 18, 23, 29

Math coprocessor 4, 16

Memory requirements 4

Milage cost 8, 28

0

Office rental costs 2, 8, 9, 31

Office space requirement 8, 28

Opening costs 2, 8, 9, 31

Optimal POD display 2, 13, 17, 32-35

OUTLINE. id file 5, 7, 11

P

PASCAL 1 , 4

POD file 5, 8-9, 11, 23, 26, 28, 37

POD map key 26-27

POD site display 2, 12, 17, 23-27

POD site modification 2, 12, 17, 23-27

POD site types 8, 12, 26

PODSITE . id file 5, 8-9, 11, 23, 26, 28, 37

PONAMES . id file .5, 7, 8

Post office names 8

Potential POD sites 2, 8, 9, 12, 17, 23, 26, 28, 29

39
Previous map 2, 14, 21, 25, 34

Printer 4, 7, 13, 36, 37

Program files 5

R

Ranges 18, 19, 22

Rental costs 2, 8, 9, 31

Report file 2, 13, 16, 17, 36, 37

REPORT. id file 36, 37

Resolution of screen 4

S

Screen resolution 4

Set color 12, 15, 17, 23, 26, 27

SET DISPLAY statement 7 Setting up a POD location problem 2, 12, 23, 28, 29

Software requirements 4

SOLVER.COM 5 Solving a POD location problem 1, 2, 12, 17, 28-31

Solution computation 1, 29-31

Solution display 2, 13, 17, 32-35

Solution map key 35

SOLUTION. id file 37

Staff requirements 2, 13, 17, 36

Staff totals 8, 9, 28

Staffing factors 9, 11, 36

State boundary file 5, 7, 11

State outline map 13, 14, 19, 23, 32

Switching device drivers 7

I

Taxpayer travel cost weight 12, 28

Top menu 12, 16-17

TRANSFER. id file 37

Travel costs 2, 28-29, 31

Travel difficulty factors 2, 12, 29

Travel distance limit 8, 9, 28, 29

Trip factors 9, 11, 36

U

Updates 3, 8, 11

V

VDI.SYS 5, 6, 7

VDIDY004 . SYS 5, 6, 7

VDIDY010 . SYS 5, 6, 7

W

Work files 37

Workload categories 10, 11, 12, 18, 28

Workload file 3, 5, 9-11, 18, 29

Workload display 2, 12, 17, 18-22

Workload key 22

Workload ranges 18, 19, 22

WORKLOAD. id file 5, 9-11, 18, 29

40
Workstation error 7, 16

Z

Zero zip codes 15

Zip code assignments 2, 13, 17, 30, 34, 36

Zip code boundary file 5, 7, 11, 18, 23, 29

Zip code map display menu 14-15, 21, 25, 34

ZIPCODE. id file 5, 7, 11

Zoom 2, 12, 13-14, 20, 21, 24, 25, 33, 34
NBS-1 1 4A (REV. 2*6C 1 U.S. OEPT. OF COMM. 1. PUBLICATION OR 2. Performing Organ. Report NoJ 3. Publication Date BIBLIOGRAPHIC DATA

REPORT NO.

SHEET (See instructions) NBS I R86- 3471-1 SEPTEMBER 1988

4. TITLE AND SUBTITLE

The Internal Revenue Service Post-of-Duty Location Modeling System (version 4.0)

- User's Manual

5. AUTHOR(S)

Paul Domich, Richard Jackson, Marjorie McClain

6. PERFORMING ORGANIZATION (If joint or other than NBS. see instructions)

NATIONAL BUREAU OF STANDARDS

U.S. DEPARTMENT OF COMMERCE

GAITHERSBURG, MD 20899

7. Contract/Grant No.

S. Type of Report & Period Covered

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City , State, ZIP)

The Research Division

U. S. Internal Revenue Service

1201 E St., N.W.

Washington, DC 20224

10. SUPPLEMENTARY NOTES

[~

1 Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bibliography or literature survey, mention it here)

This report is a user's guide for a microcomputer package which was designed by

the National Institute of Standards and Technology (formerly National Bureau of

Standards), to assist the Internal Revenue Service in choosing locations for its

posts-of-duty which will minimize costs to the IRS and to the taxpayer. The

user may select the types of costs to be considered and may specify potential

locations for new posts-of-duty. The system displays maps showing workload for

a district, current post-of-duty locations and new post-of-duty locations. This

manual provides hardware and software requirements for the system, installation

procedures, data file formats, and detailed operating instructions.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolons)

facility location; interactive graphics; greedy heuristic; interchange

heuristic; personal computer; microcomputer; zip code map

13. AVAILABILITY

ly | Unlimited

| | For Official Distribution. Do Not Release to NTIS

| | Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402.

|X | Order From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

46

15. Price

$11,95

uscomm-oc aoo-pso

r