Analytic Hierarchy Process

AHP Background

One model I want to explore today is the Analytic Hierarchy Process (AHP) that was developed by Thomas L. Saaty in the 1970’s as a tool for choosing an option using a set of weighted criteria.

For example, we may choose a software package on the basis of criteria such as supported features or functions, scale-ability, quality (fitness for purpose, fitness for use), security, availability and disaster recovery. AHP provides a mechanism for weighting the criteria by interviewing several members of staff for one-by-one assessments of relative importance, which can then be transformed into relative weightings using an eigenvector transformation.

The idea of using multiple criteria to assess multiple options is not new. AHP enhances the ability to weight the assessment criteria using feedback from multiple stakeholders with conflicting agendas. Rather than determining a “correct” answer it assesses the answer most consistent with the organization’s understanding of the problem.

Other use cases can include project portfolio optimization, vendor selection, plant location, hiring, and risk assessment. More information can be found at the International Journal of the Analytic Hierarchy Process (free registration).

Simple AHP hierarchy with associated default priorities.

Applications in ITSM

In the field of ITSM there a examples of papers that describe the instances in which AHP was used.

The paper “EDITOR-IN-CHIEF ENRIQUE MU USES AHP TO HELP CITY OF PITTSBURGH MOVE TO THE CLOUD” (free registration) briefly discusses Professor Enrique Mu’s application of the AHP for the City of Pittsburgh’s efforts to migrate IT functions to cloud providers. The decision period spanned several months and was considered strategic for the city.

Another paper “The critical factors of success for information service industry in developing international market: Using analytic hierarchy process (AHP) approach” (paywall) discusses the use of AHP for analyzing critical success factors in international market diversification for information service providers in Taiwan. They interviewed 22 participants (CEO’s, experts, consultants) to generate pairwise comparisons of CSF’s, with which the AHP method was able to distill into factor weighting. These factor weightings could be used by specific information service providers to determine whether or not they should consider entering specific markets.

In “A Method to Select IT Service Management Processes for Improvement” (free access to PDF) Professors from School of Management & Enterprise at University of Southern Queensland used AHP as part of a method for ranking ISO2000 process priorities for improvement. This particular paper is worth exploring in much greater detail because, in my experience, the prioritization or process or service improvement initiatives can be very painful at organizations, particularly those with multiple influential stakeholders with incompatible or conflicting requirements.

Last but not least, In “DECISION SUPPORT IN IT SERVICE MANAGEMENT: APPLYING AHP METHODOLOGY TO THE ITIL INCIDENT MANAGEMENT PROCESS” (free registration) Professors at the FH JOANNEUM University of Applied Sciences in Graz, Austria discuss the use of AHP in prioritizing Incidents. In their specific implementation they used four decision criteria to prioritize Incidents:

  1. Number of customers affected
  2. Whether “important” customers are affected
  3. Penalty or cost of the outage
  4. Remaining time until violation of the service level target

IT organizations typically use simplified “rules of thumb” methods for prioritizing Incidents based on Impact and Urgency. Notably three of these four factors are typically included inside variants of the schema. Please see my discussion in Incident prioritization in detail (which also avoids the explicit use of SLAs in evaluating Incident resolution).

I don’t find the prioritization of Incidents to be a particularly strong candidate for AHP analysis. High priority incidents are relatively rare and are generally handled one at a time or by non-overlapping resources. Lower priority incidents (routine break-fixes for Services Desk) can be handled first-come-first-service or using the relatively crude but quick methods described in ITIL.

Prioritization of Problems seems a more suitable candidate for AHP because a) Problem resolution can require days or weeks, b) multiple Problems may be active and contending for resources, and c) the resolution or Problem can deliver much greater long-term financial impacts for organizations. The principles and underlying support system would be similar.

Other uses of AHP that merit further investigation include:

  • Prioritization of service and process improvement initiatives
  • Selection of ITSSM tools
  • Selection of vendors (in support of the Supplier Management function / process of Service Design) and/or cloud providers
  • Activity prioritization in environments of resources in multi-queuing environments (leveling of activities across multiple processes and/or projects)