AHP Online System

As I was asked by many visitors, how to evaluate priorities and alternatives for a whole project in AHP, I have realized an online solution, where you can define a hierarchy, get the priorities for all categories and evaluate alternatives. The project is realized in PHP.

Links

Please rate the software at the end of this post!

How to use the tool

The online template is easy to use, three steps are necessary:

1. 1. Define the objective and relevant criteria of your decision problem and structure them in a hierarchy.

1. 1. Compare criteria in categories and sub-categories with respect to the objective to find their weights based on pairwise comparisons.,

1. Name a set of alternatives and compare, how good they match your decision criteria. Again pairwise comparisons based on the AHP are used.

1. Define Hierarchy

Hierarchies are defined in a text field using the following simple syntax:

Each branch in the hierarchy is defined by its node (the category) and the node’s leafs (the sub-categories). The node is followed by a colon, leafs are separated by comma, and a branch is closed by a semicolon:

category: sub-category 1, sub-category 2, sub-category 3;

If a sub-category branches out in further sub-categories, you add a line, repeating the sub-category’s name (case sensitive!) as a new node, i.e. followed by a colon:

sub-category 1: sub-sub-1, sub-sub-2;

2. Compare Criteria

To find the weight (importance) of criteria, click AHP to start pairwise comparisons. Compare each pair of criteria with respect to the project and category: which criterion in each pair is more important, and how much more on a 1 – 9 scale? Once you have finished click Calculate Result. A table with priorities for each criterion is shown.

It could happen that your pairwise comparison is not consistent, then the most inconsistent judgments are highlighted, and the most consistent judgment is marked light green. In order to improve consistency, check whether you are able to adjust your original mark by plus or minus two on the scale. Click Calculate to re-calculate. Once finished, and you are satisfied with you answers, press Submit Priorities to submit. Completed branches in the hierarchy tree are marked green.

When all comparisons in the hierarchy are done, you might continue to evaluate alternatives. Press Evaluate Alternatives. Note: You only get the selection, if all necessary pairwise comparisons are completed, or the hierarchy text input already contains pre-defined priorities. A table with criteria and alternatives will be displayed.

3. Evaluation of Alternatives

Before you start the evaluation, you might input the number and names of your decision alternatives. Enter the number (1 – 12) and press Go. Then input the names of alternatives and press ok. The procedure of pairwise comparisons is exactly the same as for the criteria. Each completed comparison is highlighted in green. When all evaluations are done, the result is shown.

4. Download

You might download the data in csv format (comma separated values) for further processing in a spread sheet program. The table starts with a title line; then each row shows one criterion with the columns: (hierarchy level, local priority), global priority, alternatives (local and global priority).

All (decision) matrices are shown below, with category name as heading and criteria for the matrix rows. Alternatives show the heading “Alternatives for” and the respective criterion.

More Examples

Program Limitations and Input Restrictions

• Display length of category names:  45 characters max.
• Hierarchy levels 6 max.
• Nodes: 20 max.
• Each node (category) has to have at least 2 branches (sub-categories)
• Endnodes: 100 max.
• Names of categories/sub-categories have to be unique.
• Numbers as category names are not allowed (though names may contain numbers).