PC World Komputer 1999 January/pcwk_01_1999_B.iso/Lotus123/Extra/123/SOLVER/SOLVER.TXT

Text File | 1997-02-07 | 13.1 KB | 296 lines

** SOLVER FOR LOTUS 1-2-3 97 **

You can use the file SOLVE123.EXE in this directory to install a
limited-use trial version of a new Solver add-in for Lotus 1-2-3
97 Edition.  This add-in, which replaces the Solver in previous
versions of 1-2-3, is a what-if analysis tool that you can use to
find answers to problems that you define, using constraint
formulas and an objective formula to be maximized or minimized.
The Solver add-in was developed and is supported by Frontline
Systems Inc.

This README file covers the following topics:

1.  Installing the Solver
2.  Network Installation
3.  Getting Help
4.  What is the Solver Good For?
5.  Upgrading from the Solver in 1-2-3 Release 5
6.  Known Problems in this Version
7.  Downloading Updates


** Installing The Solver **

To install the new Solver, simply run the program SOLVE123.EXE on
the computer where you have installed 1-2-3 97.  You can
double-click the filename SOLVE123.EXE in Windows Explorer, or
select Run from the Start menu and type or browse to the path of SOLVE123.EXE.

You don't have to specify anything further:  Just click the Setup
button, then the OK button when prompted.  SOLVE123.EXE is a
"self-extracting archive" which creates a Solver subdirectory
within your 1-2-3 directory (for example, c:\lotus\123\solver)
and copies the necessary files into this subdirectory.  It then
registers the Solver add-in (filename SOLVER.12A) so that it
loads automatically whenever you start 1-2-3.

To use the Solver add-in from 1-2-3, select Range - Analyze - Solver
to display the main Solver Parameters dialog box.  Click the Help
button in this dialog box to access extensive how-to information
about the Solver (see "Getting Help" below).

After you install the Solver, you'll also see a sample workbook
SOLVSAMP.123 in the 1-2-3 Recently Used Files List.  You can open
this workbook, solve the problems on any of the six predefined
application sheets (sheets B through G), and practice setting up
a Solver problem on sheet A.

After you install the Solver, if you have problems registering or
auto-loading the Solver, double-click on the file SOLVER.HLP in
the Solver subdirectory, and read the section "Custom Installation".

To deactivate the Solver, choose File - Add-Ins - Manage Add-Ins,
then click on the check mark next to the filename SOLVER.12A so
that the check mark disappears.  Then click Done.  To remove the
Solver add-in completely from your system, choose File - Add-Ins -
Manage Add-Ins and click the Remove button in the Manage Add-Ins
dialog box.  You can then delete the Solver subdirectory and all
the files it contains.


** Network Installation **

If 1-2-3 is installed on a network server with restricted permissions
on its directories, SOLVE123.EXE must be run once by a user (such
as your network administrator) with permissions to (i) create the
solver subdirectory in the \lotus\123 directory on the server and
(ii) copy its files to that directory.  It is OK to run SOLVE123.EXE
many times in this way, once for each client machine -- this will
simply copy the same files each time to the network server, and set
up the appropriate local Registry entries (pointing to these files)
on each client machine.  If this approach is acceptable in your environment, you can skip the rest of this section.

If you run SOLVE123.EXE from an account without permissions to write
to the server (e.g. from a typical client machine account), you will probably encounter the error message:

Error copying Solver files to hard disk.
Check available disk space and permissions.

SOLVE123.EXE exits at this point, having changed nothing on either
the client or the server machine.  This means that the local Registry
entries pointing to the Solver files have not been created, so the
Solver will not be automatically available when you next start 1-2-3
on that client machine.

If you have many client machines using 1-2-3 from a server with such
restricted permissions, and it is inconvenient to run SOLVE13.EXE on
each client machine from an account with the necessary permissions,
you can do one of two things:

1.  Download an updated version of SOLVE123.EXE from
Frontline Systems' World Wide Web site (see the
very end of this text file for details).  When you
run this updated version on a client without per-
missions to write to the server, it will display
an error message as above, but with a new choice:

Error copying Solver files to hard disk.
Check available disk space and permissions.
Press OK to continue, Cancel to quit.  If
Solver is already installed on a network
server, press OK to complete client setup.

If you click OK, SOLVE123.EXE will proceed to create
the local Registry entries, and the Solver will then
be available automatically when you next start 1-2-3.
(Note -- this assumes that you have run SOLVE123.EXE
at least once from an account WITH permissions, so
that the files are already on the server.)

2.  Manually create the Registry entries on the client.
Instructions for doing this are in the SOLVER.HLP file,
which should be in the \lotus\123\solver directory if
you have run SOLVE123.EXE previously from an account
with permissions.  To read the instructions BEFORE
you run SOLVE123.EXE, you can use the WinZip program
to open SOLVE123.EXE as an archive and extract the
SOLVER.HLP file alone.  Follow the instructions under
the topics "Modifying the Registry" and "Using the
Files Add-Ins Menu."


** Getting Help **

Frontline Systems offers telephone technical support for the
Solver on a fee basis, and also maintains an extensive World Wide
Web support site which you can access free of charge.  Lotus
Customer Support also offers some information about the Solver,
though not in the same depth as the Solver developers, Frontline
Systems.  Most questions can be answered from the Solver's online
Help, or by consulting Frontline's Web site.  We encourage you to
use the free resources first.

To learn about Solver licensing and telephone technical support,
click on the Help button in the Solver Parameters, Solver Options
or Solver Results dialog box. The Solver will display a dialog box
which reports the status of your Solver license:  If you are using
the trial version, this dialog shows how many problem solution
attempts (clicks of the Solve button) remain before the trial
license expires.  If you have purchased a permanent license, it
shows your user name and registration serial number.  To purchase
a permanent license, click the Register button.  Also included in
this dialog is telephone support and Web site information.  Click
the Help button in this dialog to reach the Solver Help file.

If you have access to the World Wide Web via the Internet, you
will find a wealth of current information about the Solver --
over 70 pages at this writing -- at Frontline Systems' Web site,

http://www.frontsys.com

Since this site is frequently updated, it is well worth while to
check it periodically for the latest news about the standard and
enhanced Solvers.  If you can't find the answer you need, you can
send email to Frontline Systems directly from your Web browser
with a single mouse click.  Or, if you're using a separate email
system, send it to:

[e-mail]

To reach Frontline Systems by phone, fax, or mail, please use:

Frontline Systems, Inc.
P.O. Box 4288
Incline Village, NV 89450, USA
Tel [phone]
Fax [phone]


** What is the Solver Good For? **

The Solver is especially useful for resource allocation problems.
The resources may be raw materials, people or equipment time,
money, or anything else in limited supply.  The decision
variables represent the amounts of resources, and the constraints
quantify the limits on their use.  The Solver finds the
allocation of resources that will maximize profit or minimize
cost, while satisfying the constraints.

The workbook SOLVSAMP.123, which is installed with the Solver
when you run SOLVE123.EXE, shows you how to:

* Assemble products from parts in inventory so as to maximize
profits
* Ship goods from plants to regional warehouses at minimum
cost
* Schedule employees to meet demand at an amusement park while
minimizing cost
* Invest cash monthly in short-term certificates of deposit to
maximize interest income
* Allocate funds to stocks in a portfolio to maximize return for
a given level of risk

The Solver uses the methods of linear programming, nonlinear
programming, and integer programming to find optimal solutions.
You'll find more information on these topics in the Solver Help
system, accessed by clicking the Help button in any of the Solver
dialogs.


** Upgrading from the Solver in 1-2-3 Release 5 **

Capabilities:  The new Solver provides linear and nonlinear
optimization capabilities similar to those of the Solver in 1-2-3
Release 5.  It also handles problems with integer constraints,
which allow users to include features such as fixed costs and
yes/no decisions (such as whether to build a new plant) in their
models.

Problem Size:  Unlike the 1-2-3 Release 5 Solver, which had no
fixed limits on problem size, the new Solver has a fixed upper
limit of 200 decision variables, and 100 constraints for
nonlinear problems.  But you will be able to solve problems on
most modern PCs all the way up to this limit, which in practice
is substantially larger than the 1-2-3 Release 5 Solver could
handle in the same amount of memory and allowed solution time.
If you need to solve larger problems, contact Frontline Systems
about enhanced versions of the Solver with more capacity and
speed.

Converting Models:  Solver models created in 1-2-3 Release 5 may
be easily converted into the form required by the new Solver.
Just follow these steps: Open your 1-2-3 Release 5 worksheet
containing a Solver problem.  Select Range - Analyze - Solver to
display the Solver Parameters dialog.  Type or select the
objective (cell to be maximized or minimized) and the range of
adjustable, or variable cells.  Then click the Add button to
add constraints.  In the Cell Reference edit box, select the
range of constraint formula cells in your 1-2-3 Release 5 model,
then click OK without selecting anything else.  The new Solver
will separate your constraint formulas into their "left hand
sides", relations (<=, =, >=) and "right hand sides" automatically.
NOTE:  This can only be done once, since your constraint formulas
are modified in the process!

Converting Macros:  If you have written 1-2-3 macros that include
commands such as {SOLVER-DEFINE} to control the 1-2-3 Release 5
Solver, you'll find that the new Solver supports the same
commands, with a few changes in the arguments.  The new Solver
also sports a complete programmable interface for LotusScript,
which will be the preferred approach for implementing new
applications.  NOTE: The macro commands are best used as a
transition aid -- you are strongly encouraged to convert your
applications to LotusScript.


** Known Problems in this Version **

There are two known problems in the Solver version included on
the Lotus 1-2-3 and SmartSuite CD-ROMs.  Both of these problems
affect only advanced use of the Solver through LotusScript:

1.  The SolverChange() function - Form 2 - which is used to change
a block of decision variables programmatically from Lotus-
Script, does not work as expected and is incorrectly described
in the Solver Help file.  You can work around this problem by
using SolverDelete() - Form 2 followed by SolverAdd() - Form 2
instead of SolverChange() - Form 2.

2.  If you (1) call SolverAdd() - Form 2 to add a block of decision
variables, (2) call SolverAdd() - Form 2 a second time to add
another block, then (3) call SolverDelete() - Form 2 to delete
the first block, you will not get the correct result (i.e. the
first block deleted and the second block remaining).  You should
never need to do this in your LotusScript code, but there is no
simple workaround if you do.


** Downloading Updates **

If you encounter problems, such as the permissions issue described
under "Network Installation" or the two "Known Problems" mentioned
above, you can download a free, updated version of SOLVE123.EXE from
the Frontline Systems' World Wide Web site.  To do this:

1.  Visit Frontline Systems' home page http://www.frontsys.com.

2.  Click on "SIGN UP for our Private Web for Solver Users" and
fill out the registration form (this is free).

3.  Your sign up should be confirmed immediately, and the home page
of the Private Web should appear.

4.  Before downloading the update, you're encouraged to take a look
at the messages posted in the discussion forum for the latest
news.  You can also post your own messages.

5.  Click on the "Download" link and follow the instructions to
download the latest version of SOLVE123.EXE.

Note that downloading and installing a new SOLVE123.EXE will have no
effect on your trial usage of the Solver -- you will continue with
the same number of "solves" remaining as you had before.  If you
download and install a new version of SOLVE123.EXE after purchasing
a permanent license, you permanent license will remain in effect.