An Assessment
ADVISORY
By Dr. Kenneth Smith, PMP
Honolulu, Hawaii
& Manila, The Philippines
We Dig Deep, While Others Sleep
Ways of Working for Project Professionals
Background. The impetus for this article was Dr. Paul Giammalvo’s admonition in the January 2026 PMWJ to STOP USING PERT because it does not meet the 5 attributes of the Scientific Method, and there are no results showing its consistent successful application; so it is ‘nothing more than an unsubstantiated marketing claim’.[1] Given his considerable experience in project management as a contractor & asset owner, as well as continuing to be a serious scholar and world-wide teacher / mentor, I do not treat Paul’s perspective lightly.
However — as I expressed in my February 2026 rebuttal [2] — from my experience as a career-long ‘hands-on’ PERT-practitioner, government employee & consultant for various governments and international agency-sponsored projects, the fundamental flaw with PERT was not its formula, but rather misapplication by those using it.
Although unable to cite projects attributing their success to PERT, I also question whether any time-estimating planning technique could be the principal cause-effect for subsequent schedule success — or slippage — in the largely uncontrollable VUCA[3] project management environment.
Paul’s second strike was for PERT to be replaced with Excel-based or even more sophisticated statistical Monte Carlo simulation software that can incorporate skewness, to generate more realistic profiles and probabilities for planning.
While no longer a practitioner; during semi-retirement I have continued to share my waning knowledge, experience — and opinions — through PMWJ, as well as in intermittent seminars & workshops. However, provoked by Paul, I stirred from my comfort zone to re-examine the concepts, structure and process underlying PERT vis a vis other schedule-planning approaches for estimating project activity durations; as well as to update myself regarding the utility of Monte Carlo’s iterative simulation approach as another technique and tool for project planning, monitoring & management.
Here are my findings, as well as the review process and data on which they are based.
More…
To read entire article, click here
How to cite this article: Smith, K.F. (2026). Approaches for Estimating Activity Durations: An Assessment. PM World Journal, Vol. XV, Issue IV, April. Available online at https://pmworldjournal.com/wp-content/uploads/2026/04/pmwj163-Apr2026-Smith-Approaches-for-estimating-activity-durations-and-probabilities.pdf
About the Author
Dr. Kenneth Smith
Honolulu, Hawaii
& Manila, The Philippines
Initially a US Civil Service Management Intern, then a management analyst & systems specialist with the US Defense Department, Ken subsequently had a career as a senior foreign service officer — management & evaluation specialist, project manager, and in-house facilitator/trainer — with the US Agency for International Development (USAID). Ken assisted host country governments in many countries to plan, monitor and evaluate projects in various technical sectors; working ‘hands-on’ with their officers as well as other USAID personnel, contractors and NGOs. Intermittently, he was also a team leader &/or team member to conduct project, program & and country-level portfolio analyses and evaluations.
Concurrently, Ken had an active dual career as Air Force ready-reservist in Asia (Japan, Korea, Vietnam, Indonesia, Philippines) as well as the Washington D.C. area; was Chairman of a Congressional Services Academy Advisory Board (SAAB); and had additional duties as an Air Force Academy Liaison Officer. He retired as a ‘bird’ colonel.
After retirement from USAID, Ken was a project management consultant for ADB, the World Bank, UNDP and USAID.
He earned his DPA (Doctor of Public Administration) from the George Mason University (GMU) in Virginia, his MS from Massachusetts Institute of Technology (MIT Systems Analysis Fellow, Center for Advanced Engineering Study), and BA & MA degrees in Government & International Relations from the University of Connecticut (UCONN). A long-time member of the Project Management Institute (PMI) and IPMA-USA, Ken is a Certified Project Management Professional (PMP®) and a member of the PMI®-Honolulu and Philippines Chapters.
Ken has two KENBOOKS: 1. Project Management PRAXIS which includes many innovative project management tools & techniques; and describes a “Toolkit” of related templates, and 2. MUSINGS on Project Management — a compilation of contemporary concerns in project planning, monitoring & evaluation, with some tools & techniques suggested for their solution. Either or both books are available from Amazon, and their related templates are available directly from him at kenfsmith@aol.com on proof of purchase.
To view other works by Ken Smith, visit his author showcase in the PM World Library at https://pmworldlibrary.net/authors/dr-kenneth-smith/
[1] Giammalvo, P. D. (2026). What Do We Do AFTER Calculating Our Average Costs or Durations? PM World Journal, Vol. XV, Issue I, January. https://pmworldlibrary.net/wp-content/uploads/2026/01/pmwj160-Jan2026-Giammalvo-what-we-do-after-calculating-averages.pdf
[2] Smith, K.F. (2026). In Defense of PERT-PLUS. PM World Journal, Vol. XV, Issue II, February. https://pmworldlibrary.net/wp-content/uploads/2026/02/pmwj161-Feb2026-Smith-in-defense-of-PERT-Plus-2.pdf
[3] VUCA: Volatile, Uncertain, Complex, Ambiguous
