Joe Zhu, Ph.D. Professor of Operations Analytics
Foisie School of Business
Worcester Polytechnic Institute
100 Institute Road
Worcester, MA 01609
Phone 508-831-5467• Fax 508-831-5720•
DEAFrontier Support

Download Most Recent Version of OpenSolver

Please first visit to download the OpenSolver software. Then replace the OpenSolver.xlam download from with this one
Please Use this OpenSolver.xlam
Otherwise, if you use the OpenSolver.xlam obtained directly from, you may get OpenSolver user dialogs during calculations and you need to manually close the dialogs to continue the calculation

The following questions/issues are addressed:

How many DMUs can I solve using DEAFrontier software?

i) When you use the DEAFrontier version that uses Excel Solver as the engine for solving the DEA models, the limits are set by the related Solver product. In other words, DEAFrontier software's capacity is set by the Excel Solver. Please check for problem sizes that various versions of Excel Solver can handle.

Some DEA models are coded in a way that they can be solved using just the standard Excel Solver (2007 and earlier) and can have unlimited number of DMUs (as long as the data can be placed in an Excel sheet), for example, the multiplier models.

However, if the number of DMUs becomes very large, the standard Excel Solver may not be efficient in solving large DEA problems. For example, it may take significant amount of time to finish the DEA calculations with 2000 DMUs. It is recommended that the user uses Solver Platform for large-sized DEA problems.

DEAFrontier will let you know if the standard Excel Solver shipped with Microsoft Office cannot solve for a particluar data set.  If that is the case, then one needs to upgrade the standard Excel Solver, or use the DEAFrontier with OpenSolver.

ii) When you use the DEAFrontier version that uses the open source software "OpenSolver" which uses the open source COIN-OR CBC optimization engine, there are no artifical limits on the numbers of DMUs, inputs and outputs. "OpenSolver" is an Open Source linear and integer optimizer for Microsoft Excel. Please visit for more information.

The user receives all the above versions of DEAFrontier in the software package. Specifically, the user will receive 1) DEAFrontier for Excel 2007-2016, 2) DEAFrontier for OpenSolver under Excel 2007-2016, 3) DEAFrontier for use with Solver Platform and Excel 97-2003.

What DEA models are included in DEAFrontier?

DEAFrontier has lots of DEA models including many of the standard DEA models/approaches, cross efficiency, super-efficiency, Malmquist, Bootstrapping, Two-stage Netwrok, Additive models and many others. Please download the excel file "models.xls" for DEA models included. A user manual with detailed DEA models will be provided once the software is purchased.
Compile Error in Hidden Module
When I try to run the DEAFrontier software (and call the DEA models within the DEAFrontier menu), I get an error message saying "compile error in hidden module". As a result, I am not able to run the DEAFrontier software?

This error message means that the Excel Solver cannot be found by the DEAFrontier. Try the following procedure:

Step 1: Open Excel
Step 2: Open/Load Solver (and then close the Solver parameters box)
Step 3: Open DEAFrontier -- namely double click the DEAFrontier file. Note if you use the standard Excel Solver, you need to open "DEAFrontier.xlam".

Before steps 1 and 2, " DEAFrontier.xlam " should not be loaded. In other words, when you first open Excel, you should not see the DEA add-in menu.

Please see the next question "How do I load/open DEAFrontier software?"

The following four possible cases are related to this particular error message:

Case 1:  the Excel Solver is not installed (when the Microsoft Office is installed);

Locate Excel Solver under Excel 2007-2016
Locate Excel Solver under Excel 2003

Case 2: You are using the DEAFrontier with OpenSolver. But the OpenSolver is not loaded priori to loading/opening the DEAFrontier software. (Please see "How do I load/open DEAFrontier software?")

Case 3: If you are using Excel 97-2007, in order to run the DEAFrontier software, Excel Solver must be installed. The Excel Solver Parameters dialog box has to be displaced once before the DEAFrontier software is loaded. Otherwise, the DEAFrontier software may not run. (Please see "How do I load/open DEAFrontier software?")

Please download this ReadMeFirst.pdf (234 kb) for detailed information and the correct procedure on running the DEAFrontier software.

Case 4: You are using a non-English version of Excel (see the last question).
This is very unlikely case if you use Excel 2007 or newer versions.

How do I load/open DEAFrontier software?
Load DEAFrontier under Excel 2007-2016
For some Excel 2007 version users, you may need to follow the instructions under Excel 97-2003.

Load DEAFrontier under Excel 97-2003

Use DEAFrontier with OpenSolver
Note that in this case, Excel Solver must also be loaded.
For Excel 97-2007, Solver Parameters dialog box has to be displaced once before the DEAFrontier software is loaded. In other words, before you double-click the DEAFrontier Software file to open/load the software, Excel Solver Parameters dialog box has to be displayed and closed.

When I open the DEAFroniter software in Excel, the Excel loads and then the Add-In tab does not appear

This indiates that Excel actually does not open the DEAFrontier file. The MS Office security update changed how Excel handles documents that are opened from untrusted locations (such the Internet zone/email) which are not supported in Protected View. Therefore files open from such locations are now blocked. If the DEAFroniter file will not open in Excel, the user will need to manually trust the file before they open it in Excel. To do so,

1. You can unblock access for individual files you know are safe. To do this:
Right click on the file and choose Properties
On the General tab, click Unblock
Click OK

2. You can make use of existing Trusted Locations capabilities in Excel 2010, 2013, and 2016 via File -> options -> Trust Center -> Trust Center Settings -> Trusted Locations.

How long does DEAFrontier take to finish a single run?

This depends on the size of your problem, namely, # of DMUs, inputs and outputs, and Excel Solver's speed. In a case of 4000 DMUs, it takes about 10 seconds to solve for one DMU under Solver Platform. The same is true for OpenSolver or COIN-OR CBC optimization engine.

Runtime error with Risk Solver Platform

A few cases have been reported that Excel encounters a runtime error and has to stop the program when the Risk Solver Platform is installed. The causes of that is due to the Solver product. Users who plan to use the DEAFrontier under other Solver products are strongly advised to test the free DEAFrontier version under Risk Solver Platform. As suggested by LongFei Chen from National Chiayi University (Taiwan), one may solve the above issue by packing the DEAFrontier into a .rar or .zip file and try to run it from a WinRAR or WinZIP environment.

Under which Excel (Windows) version does DEAFrontier operate?

Excel XP-2016 under Windows XP-Windows 8, 8.1, and 10.
DEAFrontier has two versions. One version for Excel 2007-2016 and the other for Excel 97-2003.
Both versions will be provided.
DEAFrontier for Excel 2007-2016 does not work under other versions of Excel. (DEAFrontier for Excel 97-2003 does not work under Excel 2007-2016.)

How do I know if my Excel Solver is added as an Add-In in Excel (and is working properly)?

You can download this "solvertest.xls" (30 kb) to do a test under Excel 97-2003.

This link provides the Excel test file "solvertest2007.xls" (40 kb) for Excel 2007-2016. (Please do not use this file under Excel 97-2003)

I am using a non-English version of the Microsoft Office. I have followed the correct procedure to run the DEAFrontier software as described in the ReadMeFirst.pdf. But I still get the error message "complie error in hidden module".

This has happened under non-English Excel 97-2003.

For some non-English versions of Microsoft Office, DEAFrontier software may still produce an error message if one attempts to use the DEA models. This may due to the fact that the "Solver.xla" is renamed in a local language in the Microsoft Office. For example, in some Finnish versions of Microsoft Office, "Solver.xla" is actually named as "ratkais.xla". In order to use the DEAFrontier software, one has to make sure that the Excel Solver is named as "Solver.xla" in its directory (usually Program Files\Microsoft Office\Office 10\Library\Solver).

If your Excel Solver file is named in your language, here is how to resolve the problem:
(Thanks to Räty Tarmo for providing the suggestions.)

1. Make a copy the *.xla file in its directory and rename its as "solver.xla".
2. Remove the non-English Excel Solver by unchecking the "Solver" add-in in your Excel Tools/Add-Ins window.
3. Install the renamed copy using Browse in Tools/Add-Ins window.

Alternatively, one can use the File/Open menu item to load the renamed Solver.xla manually from its directory. In this way, one does not have to "remove & install" as described above.

One can also run the Excel Solver from other directory. This is actually what one has to do if one uses the licensed premium solver platform or equivalent software. Therefore, if one does not want to change the original installation, one can create a new directory and copy all the Excel Solver related files into this new directory and then follow the above steps.

Finally, one can also use the VBA window/tools/references to see if the English "Solver" appears. If so, one should be able to run the DEAFrontier software.