Analysis

Analysis is one of the key concepts in Decision Analysis. In contrast with evaluation, which is merely a calculation directed from inputs (data describing alternatives) to outputs (evaluation results), analysis is understood as an active involvement of participants who are trying to find answers to questions such as:

  • Are alternative evaluations in accordance with expectations? Are they ‘correct’? If not, why?

  • How do the alternatives compare with each other? Which one is the best and why?

  • Can we explain and justify the evaluations? What are the most important strong and weak points of individual alternatives?

  • What if something changes: What if we try a new alternative? What if an alternative becomes unavailable? What if some alternative’s characteristics change?

  • How sensitive is the evaluation to small changes of the model (such as addition or deletion of an attribute, modification of some decision rules)?

In other words, analysis is a creative and possibly repetitive application of DEX models aimed at better understanding of the decision problem, better understanding of alternatives, their characteristics and consequences, and better justification of the decision. In general, this involves techniques such as: what-if analysis, sensitivity analysis, stability analysis, etc.

In DEX software, analyses are mostly carried out on the evaluation page, where the user can:

  • Review intermediate and overall results of evaluation. In order to clarify and justify the results, they may focus on particularly bad or good evaluations.

  • Change individual alternative values and immediately see the effects on evaluation results.

  • Perform other analyses, described below.

Typical analysis operations, implemented in DEX software, include:

  • Selective explanation: Identifying particular advantages and disadvantages of an alternative.

  • Compare Alternatives: Comparing an alternative with some other alternatives.

  • Plus-Minus Analysis: Investigating the effects of changing one basic alternative value by one or more steps up and down.

  • Target Analysis: Investigating the changes of multiple basic alternative values that may improve or degrade evaluation at some selected attribute.

For examples of analyses, see Car Evaluation and Employee Selection.

For more detailed description of analyses, refer to DEX Software: DEXi and DEXiWin.