DEA Analysis

The V•I•S•A DEA Extension uses DEA (Data Envelopment Analysis) technology to automate the testing of alternatives for efficiency on pairs of criteria.

It automatically adjusts weights to show selected alternatives in the best light. This enables fast review of the alternatives so that obviously dominated options can be removed from investigation. Carefully focused discussion can be promoted about appropriate weights.

Here is how to use the facility.

The DEA extension assumes you have a V•I•S•A model with a structure similar to this example:

University departments are being measured on their success (outputs) against costs (inputs).

A department which is good (high score) on both outputs and inputs will be better than one which is poor (low score) on both. But the score at the input and output level in the above hierarchy depends on the weights applied at the next level down. Can agreement be reached on these weights? Is there a set of weights which can make an option look better than the others? Is this set of weights unreasonable?

All these questions are useful to ask in a discussion where a group of people are trying to reach consensus.

In the V•I•S•A DEA extension you can use V•I•S•A’s automated facility to adjust weights to try to move any option to the “efficient frontier”. (That is move it to a point where it is not “dominated” by any other options).

Here is how:

Open up an XY chart for Inputs against Outputs.

Click RIGHT on any of the alternatives displayed in the chart to have V•I•S•A’s DEA technology attempt to move the alternatives to the efficient frontier by changing the weights at the level immediately below the two criteria plotted in the graph.

If it is not possible to move the option to the efficient frontier (there is no feasible set of weights) then a message will be displayed to warn you that the changes made do not result in reaching the efficient frontier.

Note:

The V•I•S•A DEA extension is based on the research of Dr Valerie Belton published in: V Belton and S P Vickers “Demystifying DEA - a Visual Interactive Approach Based on Multiple Criteria Analysis” Journal of the Operational Research Society Vol 44,9 pp 883-896 to which the reader is referred for a detailed discussion of this topic.