AHP Timeline

Thomas L. Saaty develops the Analytic Hierarchy Process while working at Wharton Business School. His interest in the study of complex decision problems came from earlier work on conflict resolution and disarmament for the U.S. State Department.

The first paper describing the AHP is published:

An eigenvalue allocation model for prioritization and planning

Thomas L. Saaty

The seminal journal paper formally introducing the AHP's mathematical foundations is published in the Journal of Mathematical Psychology:

A Scaling Method for Priorities in Hierarchical Structures

Thomas L. Saaty

The canonical AHP reference book is published by McGraw-Hill:

The Analytic Hierarchy Process: Planning, Priority Setting, Resource Allocation

Thomas L. Saaty

Thomas L. Saaty and Ernest Forman found Expert Choice, the first commercial software implementation of the AHP, helping drive adoption of the method in industry and government.

The original rank-reversal critique of the AHP is published in Omega, starting the longest-running argument in the field:

On a short-coming of Saaty's method of analytic hierarchies

Valerie Belton, Tony Gear

The proof that the geometric mean is the only valid way to aggregate group judgments is published in the Journal of Mathematical Psychology:

Procedures for synthesizing ratio judgements

János Aczél, Thomas L. Saaty

The formal axioms underpinning the AHP's ratio-scale priorities are published in Management Science:

Axiomatic foundation of the analytic hierarchy process

Thomas L. Saaty

Saaty's accessible overview of the method, still the best first paper to hand a newcomer, is published in Mathematical Modelling:

The analytic hierarchy process — what it is and how it is used

Thomas L. Saaty

The standard method for deriving priorities from incomplete pairwise comparisons is published in Mathematical Modelling:

Incomplete pairwise comparisons in the analytic hierarchy process

Patrick T. Harker

ISAHP1988 conference held at Tianjin, China.

The most cited paper on the Analytic Hierarchy Processs published in Mathematical Models for Decision Support:

What is the Analytic Hierarchy Process?

Thomas L. Saaty

A widely cited accessible introduction to the AHP is published in the European Journal of Operational Research:

How to Make a Decision: The Analytic Hierarchy Process

Thomas L. Saaty

The sharpest critique exchange in the AHP literature appears in Management Science, with Saaty's reply published in the same issue:

Remarks on the analytic hierarchy process

James S. Dyer

ISAHP1991 conference held at Pittsburgh, Pennsylvania, USA.

ISAHP1994 conference held at Washington, D.C., USA.

ISAHP1996 conference held at Burnaby, British Columbia, Canada.

Saaty generalizes the AHP to decision problems with dependence and feedback, introducing the Analytic Network Process (ANP):

Decision Making with Dependence and Feedback: The Analytic Network Process

Thomas L. Saaty

The distinction between aggregating a group's judgments (AIJ) and its priorities (AIP) is settled in the European Journal of Operational Research:

Aggregating individual judgments and priorities with the Analytic Hierarchy Process

Ernest Forman, Kirti Peniwati

ISAHP1999 conference held at Kobe, Japan.

The International Society on Multiple Criteria Decision Making awards the MCDM Gold Medal to Thomas L. Saaty:

“...for the development of the Analytic Hierarchy Process (AHP) and the impact of his lifelong research contributions on several disciplines.”

ISAHP2001 conference held at Berne, Switzerland.

ISAHP2003 conference held at Bali, Indonesia.

ISAHP2005 conference held at Honolulu, Hawaii, USA.

Thomas L. Saaty is awarded the 2007 Akao Prize by the Quality Function Deployment Institute.

ISAHP2007 conference held at Valparaiso, Chile.

The Institute for Operations Research and the Management Sciences (INFORMS) awards its Impact Prize to Thomas L.Saaty, stating that:

“The AHP has revolutionized how we resolve complex decision problems... the AHP has been applied worldwide to help decision makers in every conceivable decision context across both the public and private sectors, with literally thousands of reported applications.”

ISAHP2009 conference held at Pittsburgh, Pennsylvania, USA.

The International Journal of the Analytic Hierarchy Process (IJAHP) publishes its first issue, giving the field its own dedicated open-access journal.

ISAHP2011 conference held at Sorrento, Italy.

A review of developments of the AHP since its inception is published in Expert Systems with Applications:

Review of the main developments in the analytic hierarchy process

Alessio Ishizaka, Ashraf Labib

A paper describing the fundamental concepts underlying the AHP is published:

The Seven Pillars of the Analytic Hierarchy Process

Thomas L. Saaty, Luis G. Vargas

ISAHP2013 conference held at Kuala Lumpur, Malaysia.

Theme: Better world through better decision making

A paper describing the author's practical experience applying the AHP in corporate environments is published. A link to the author's AHP spreadsheet is provided:

Implementing the analytic hierarchy process as a standard method for multi-criteria decision making in corporate enterprises–a new AHP Excel template with multiple inputs

Klaus D. Goepel

ISAHP2014 conference held at Washington, D.C., USA.

Theme: Beyond Decision Making

ISAHP2016 conference held at London, UK.

Thomas L. Saaty, creator of the AHP and ANP, dies in Pittsburgh aged 91. He remained an active researcher until the end of his life. See the INFORMS memoriam and the Pittsburgh Post-Gazette obituary.

A citation-network history of four decades of AHP research is published in the International Journal of Production Research:

The state of the art development of AHP (1979–2017): a literature review with a social network analysis

Ali Emrouznejad, Marianna Marra

The standard post-2011 review of AHP integrations and applications is published as an Invited Review in the European Journal of Operational Research:

The state-of-the-art integrations and applications of the analytic hierarchy process

William Ho, Xin Ma

ISAHP2018 conference held at Hong Kong, HK.

Theme: AHP/ANP in Technology, Entrepreneurship and Corporate Social Responsibility

The reference paper describing AHP-OS, a free online AHP tool widely used in academic studies, is published in the International Journal of the Analytic Hierarchy Process:

Implementation of an online software tool for the Analytic Hierarchy Process (AHP-OS)

Klaus D. Goepel

A simplified version of the Analytic Hierarchy Process method is published in MethodsX:

AHP-express: A simplified version of the analytical hierarchy process method

Jose Eugenio Leal

An introduction to the AHP for kids is published in Frontiers for Young Minds:

What to Do? Let's Think It Through! Using the Analytic Hierarchy Process to Make Decisions.

Jenee A. Jagoda, Steven J. Schuldt, Andrew J. Hoisington

ISAHP2020 conference held virtually.

Theme: AHP/ANP: The Next Generation

ISAHP2022 conference held virtually.

Theme: Decision-Making in Business Practice

ISAHP2024 conference held virtually.

Theme: Enhancing Decision Making with AI