Tag: AHP

AHP Frequently Asked Questions

Over the year I receive many questions about AHP, my AHP excel template and my AHP online Software. Here a selection of frequently asked questions:

General Questions

Q: I have 15 criteria and 20 alternatives, can you extend your template/software?
A: The excel template can handle up to 10 criteria, my online software is limited to 12 criteria (in one hierarchy level) and 10 alternatives. In principle it could be extended, but the limitation is inherit to the AHP method. Please read my explanations here.

Q: I have more than 10 alternatives, can I use AHP for priority evaluation of criteria and a different method for the evaluation of alternatives?
A: Yes, you can combine AHP for criteria evaluation with another method for alternative evaluation. Alternative evaluation could be done for example using a simple table with a yes/no or applicable/not applicable scale, or any other scale, e.g. Likert scale, how good the individual alternative matches the specific criterion.

Q: I have 150 participants, can I use your excel template/software?
A: My AHP excel template is limited to 20 inputs, my AHP online software can handle a (practically) unlimited number of participants. Use the AHP online software.

Q: How can I resolve the inconsistency (CR>0.1), when participants are done with their pairwise comparisons.
A: Once the pairwise comparison is done and submitted, data can not be changed and consistency ratio is what it is. Ask your decision makers to adjust their judgments  in direction of the most consistent input during the pair-wise comparisons for the highlighted three most inconsistent comparisons. Please see also my posting here.

Q: Can I use the Likert scale instead of the AHP scale?
A: No, AHP is based on the rational scale 1/9 … 1 … 9. It cannot be replaced by the Likert scale.

Q: Do you support Fuzzy AHP?
A: No, I have made no provisions to support Fuzzy AHP, neither in Excel, nor in my online software.

Q: How is the computation done, where do I find the description and formulas?
A: Please download the manual for the excel template, or the description about the  Software Implementation of AHP-OS.

Q: How can I cite your work, can you give me a reference?
A: Please cite my paper: Implementing the analytic hierarchy process as a standard method for multi-criteria decision making in corporate enterprises–a new AHP excel template with multiple inputs (Excel template) or my paper Software Implementation of AHP-OS.

AHP Excel template

Q: Can I extend the number of participants to more than 20?
A: Though it is possible in principle, the better way is to use my AHP online software with (practically) unlimited number of participants. I will not do a further extension of the template.

Q: Do you have a version of the Excel template w/o multiple inputs?
A: Yes, a simplified version is available on request from the author.

Q: How can I do alternative evaluation using your Excel template.
A: It is not possible. The template can only handle one category of a hierarchy and calculate the priority of one set of criteria.

AHP Online software

Q: If I have a group of decision makers, do they need to register for the online software?
A: No, they don’t need to register. As the owner of a project you get a link for group decision inputs. Simply send them the link, and they can start the pairwise comparisons.

Q: Can I erase/delete inputs from individual participants from the group results?
A: Yes, you can select and delete individual participants from a project .

Q: The alternative evaluation is not working?
A: Criteria evaluation (priorities) and alternative evaluation have to be handled as two different projects. Only when you have a decision hierarchy with completed comparisons and evaluated priorities, you can define the alternatives from the group result page clicking on Use consol. priorities. Define number and name of alternatives from there and save as new project. Hierarchy evaluation and alternative evaluation projects appear as type “H” for the first and type “A” for the latter in your project list.

Q: Can I get the source code of your online software?
A: Sorry, it is not an open source project.

Improving AHP consistency

In the implementation of both, AHP excel template as well as AHP online software, inconsistent judgments are highlighted and recommendations for consistent judgments are given.  How it is done, and what is the method behind?

The method is based on Saaty’s article “Decision-making with the AHP: Why is the principal eigenvector necessary“. European Journal of Operational Research 145 (2003) 85–91. He describes three methods how to transform a positive reciprocal matrix to a near consistent matrix.

In my implementation I construct the matrix εij = aij wj/wi to identify the three judgments for which εij is farthest from one. In Saaty’s paper it is shown as table 3, in my excel template it is called Consistency Error Matrix.  As I have to do it on each individual input sheet using as an approximation the RGMM (row geometric mean method) results, before calculating the eigenvector solution in the summary sheet.

AHP online software – a reminder

If you are a registered user of my AHP online software, please keep in mind and be aware:

After 3 months of inactivity, your user account will be deactivated automatically. Please reactivate, using the link provided in the e-mail, if you want to keep your data, otherwise your account and all your data will be deleted 48 hours after deactivation.

This is done to ensure a slim database and help to keep the software fast and responsive. Please also avoid multiple registrations under different user names and e-mail addresses. You can keep up to 20 projects in your account, and it should be sufficient for the majority of users.

AHP online program limits:

  • Number of hierarchy levels: 6 max.
  • Number of hierarchy nodes: 50 max.
  • Number of criteria/node: 15 max. ( 7 to 9 recommended)
  • Number of hierarchy end nodes: 150 max.
  • Number of Alternatives: 10 max.
  • String length for nodes/leafs: 35 char max.
  • Number of characters for hierarchy definition: 6000

Thank you for your cooperation, and PLEASE – as a registered user – help to support this website with a small donation. I do not have a commercial interest, but I spend a lot of time, sharing my knowledge for free, and I have running costs to keep the site alive.

Thank you!

Welcome to BPMSG – Mar 2016

Concepts, Methods and Tools to manage Business Performance

Dear Friends, dear Visitors,

The analytic hierarchy process AHP remains the main topic of this website and continues to have the most visitors. From October 2015 to now I received quite a number of questions related to my AHP excel template and my AHP online software. Here some of the typical questions (FAQs):

Q: Can I extend the number of participants to more than 20?
A: Though it is possible in principle, the better way is to use my AHP online software with (practically) unlimited number of participants. I will not do a further extension of the template.

Q: Do you have a version of the Excel template w/o multiple inputs?
A: Yes, a simplified version is available on request from the author.

Q: How can I cite your work, can you give me a reference?
A: Please cite my paper: Implementing the analytic hierarchy process as a standard method for multi-criteria decision making in corporate enterprises–a new AHP excel template with multiple inputs

Q: Do you support Fuzzy AHP?
A: No, I have made no provisions to support Fuzzy AHP, neither in Excel, nor in my online software.

Q: Can I use the Likert scale instead of the AHP scale?
A: No, AHP is based on the rational scale 1/9 … 1 … 9. It cannot be replaced by the Likert scale.

Q: How is the computation done, where do I find the description and formulas?
A: Please download my paper.

Q: How can I do alternative evaluation using your Excel template.
A: It is not possible. The template can only handle one category of a hierarchy and calculate the priority of one set of criteria.

Q: If I have a group of decision makers, do they need to register for the online software?
A: No, they don’t need to register. As the owner of a project you get a link for group decision inputs. Simply send them the link, and they can start the pairwise comparisons.

A couple of months ago I added a Donation button to the website – see below. Unfortunately, only a very small number of users used it, a big Thank You to them! PLEASE, help to support this website with a small donation. I have no commercial interest, but spend a lot of time, sharing my knowledge for free, and I have running costs to keep the site alive. Thank you in advance!

For now, please enjoy your visit on the site and feel free to leave a comment – it is always appreciated.

Klaus D. Goepel,

Singapore, March 2016

BPMSG stands for Business Performance Management Singapore. As of now, it is a non-commercial website, and information is shared for educational purposes. Please see licensing conditions and terms of use.

About the author

Welcome to BPMSG – October 2015

Concepts, Methods and Tools to manage Business Performance

Dear Friends, dear Visitors,

it’s soon coming to five years that my webpage has been online, and things getting slowly a bit messy … There was a need to clean-up the pages, posts and directories, so that the necessary maintainance will take less time, and future updates are possible. As you should know, this project is done in my free time as a hobby, I still have a full-time job for another couple of years.

Unfortunatly, during the whole process, some links were broken and it will take time to repair. Sorry, when you experience missing images or a broken link. Just let me know using my contact page. I am still working on it and plan to simplify the navigation in order  to make it easier for you to find relevant information.

AHP as one category, where you find information about the analytic hierarchy process, will stay in focus. From the start this was the nost frequently visited part of the site, and my AHP excel template slowly reaches 15 thousand (!) downloads. Under  the category Articles you find posts about other topics, mainly the concept of diversity, as I was using it for  different applications. All more personal related  topics under the category Other will move to my new personal blog – Klaus & Lita – running on my own server with topics like multicopter, programming and – maybe – cooking in future.

For now, please enjoy your visit on the site and feel free to leave a comment – it is always appreciated.

Klaus D. Goepel,

Singapore, October 2015

BPMSG stands for Business Performance Management Singapore. As of now, it is a non-commercial website, and information is shared for educational purposes. Please see licensing conditions and terms of use.

Please give credit or a link to my site, if you use parts in your work, or make a small donation to support my effort to maintain this website.

About the author

AHP online software – how it was implemented

When I was asked just now in an e-mail, how my AHP online software operates,   I realized that I have never published a description about it. Therefore, here a short summary:

The AHP-OS software implementation is based on my AHP excel template. I have published one paper about it in 2013. All mathematical formulas used, are shown in this conference paper or in the excel template manual on the last 2 pages. The online version is realized in PHP, using OOP (object oriented programming), running on a Linux server.

The core module is the ahp class. It contains the routines to fill the decision matrix from the pairwise comparisons, to find the dominant eigenvalue using the power method, and to calculate the consistency ratio.

A second important class is the hierarchy class. It translates the text file – defining the hierarchy – into a hierarchical data array. When I implemented the software, I wanted to get a flexible tool, which can be used for all kind of hierarchical problems. This was actually more difficult than the implementation of all mathematical calculations, especially under the aspect of safety and malicious online attacks. The feature also differentiates the online version from the excel implementation. The excel template cannot handle hierarchies at all.

The third important class implements the database and its management. I use SQL with either sqlite or mysql drivers. There are 4 tables:

  • one for user management (registration, password, etc.),
  • one for projects (hierarchy data, description, session code etc.),
  • one for pairwise comparisons (participants, judgments etc.) and
  • one for handling alternatives.

The rest of classes contain supporting functions, like html in/output, excel download and consolidation for group results. I use a basically two open source packages, phpMailer and phpGraphlib, the rest is all realized by myself from scratch.

Please consider a donation, it will help me to maintain the website and program.

Update 2017: AHP-OS software implementation (pdf)

Welcome to BPMSG – February 2015

Concepts, Methods and Tools to manage Business Performance

Dear Friends, dear Visitors,

time for a short update on bpmsg.com. Firstly, I wish you a healthy and successful New Year 2015, and for all of you with Chinese background: Gong Xi Fa cai – 恭喜发财, the year of the sheep is coming.

As I had a lot of other activities over the last few months, I was not very active here on my blog here, but the daily number of visitors is still increasing, and I receive feedback and questions regularly, most often about AHP. Thanks for all your comments, and please continue to give me your suggestions and ideas. My AHP online software has now more than 300 registered and active users. Please take note that users, not active for more than three month, will receive an email notification to re-activate their account within two days, otherwise their account incl. all project data will be deleted.

The latest publications, using my AHP Excel template or online software, cover areas like productivity improvement, smart TV human computer interaction, building sustainability and others. I try to keep the list of references up-to-date. Please cite my paper here, if you use my tools and plan to publish your work, and let me know about it.

Surprisingly my post about the Synology DS1513+ network attached storage (NAS) got a lot of readers. Online security seems to be an issue, and making remote online access more secure is indeed an important topic. So I opend the comment field on this post for feedback and questions.

For now, please enjoy your visit on the site and feel free to give me comment – it is always appreciated.

Klaus D. Goepel,

Singapore, February 2015

BPMSG stands for Business Performance Management Singapore. As of now, it is a non-commercial website, and information is shared for educational purposes. Please see licensing conditions and terms of use. Please give credit or a link to my site, if you use parts in your website or blog.

About the author

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