Module: Analytic Hierarchy Process (AHP)

Submitted by Michael Rastall | published 7th Jan 2013 | last updated 3rd Dec 2013
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Background to the method

Analytic Hierarchy Process (AHP) is  a type of multi-criteria assessment (MCA) technique for analyzing complex decisions. It was developed in the early 1980s to help decision-makers find the option that best suits their goal and understanding of the ‘problem’. Nowadays it is applied in a wide variety of fields (mainly engineering, business strategic management, education, quality assessment).

The method is is used to compare a set of options by using participants data, experience and judgment, and converting these into numerical values. It allows them to compare in a rational and consistent way diverse elements that are often difficult to measure (AHP measures intangibles in relative terms).

It evaluates various elements by comparing them to one another two at a time (pairwise comparison). Comparisons are made using a scale of ‘absolute judgements’ that represents how much more one element dominates another with respect to a given reference point.

AHP is very flexible and can be adapted to different needs and contexts. Criteria (or attributes) can be decided in advance or through a participatory process (increase transparency and dialogue). Criteria can be tangible and intangible, can have subcriteria and be as many as necessary. The process can involve as many participants as required. The number of alternatives to evaluate can also vary.

What are the ideal situations in which it is applied?

  • Choice - The selection of one alternative from a given set of alternatives, usually multiple decision criteria involved
  • Ranking - Putting a set of alternatives in order from most to least desirable
  • Prioritization - Determining the relative merit of a set of alternatives, as opposed to selecting a single one or merely ranking them
  • Resource allocation - Distributing resources among a set of alternatives
  • Benchmarking – Comparing processes in one organization with those of other best-of-breed organizations
  • Quality management - Dealing with the multidimensional aspects of quality and quality improvement
  • Conflict resolution - Settling disputes between actors with apparently incompatible goals or positions

Source: Wikipedia. Retrieved from: http://en.wikipedia.org/wiki/Analytic_Hierarchy_Process#Uses_and_applications

Applying the method

The AHP process involves 5 main steps:

  • Defining the problem and alternatives to evaluate.
  • Structuring the criteria for the decision-making process.
  • Pairwise comparison of options.
  • Weighting and calculation of of relative priorities (how do options fare in their pairwise comparisons).
  • Aggregate relative priorities to produce overall ranking of options.

Much more detail on carrying out the AHP can be found in our step-by-step guidance.

Strengths and weaknesses

Results change as new options/ alternatives are considered in the analysis. However, some criteria are not independent so this can bias or complicate the way in which they are assessed (clusters can be formed). Also, AHP can become complicated if lots of criteria and options are considered.

The AHP method is used in a variety of problem domains, it is widely used and is published in many studies and research papers. It is technically valid and practically useful. It can promote discussion among participants and capture different points of view. It can compare tangibles and intangibles. To compensate for drawbacks, it can be used in combination with other (objective and subjective) methods.

Added value of the method for the field of climate adaptation

AHP is being used in several adaptation studies in different EU countries as part of the Mediation project. The method does not seem to need any particular modification for use in adaptation projects but (as always) users need to be aware of the conditions of applicability of the method.

AHP can be carried out with paper and pen - as shown below - however to assist with application of the method, a software tool has been developed as part of the Climate Adaptation Options eXplorer, or ADx.


Carrying out AHP with CIFOR researchers

Example of applying the method

Climate Adaptation in Greater Banjul, Gambia

Useful portals with tools/software for AHP

Further Resources