5 December 2023

Delay Analysis – The Art of Clarity

BY: Yazeed Abdelhadi | IN: Articles


Is delay analysis a mysterious and elusive art, shrouded in ambiguity, or can it be deciphered and mastered through a strategic application of facts, knowledge, and experience?

Delay analysis involves applying knowledge and expertise to recognise, understand, and quantify delays in projects. Within the industry, various standard methods for delay analysis exist, yet there is frequently uncertainty regarding the choice and application of these methods.

The principal industry standards include the Delay and Disruption Protocol by the Society of Construction Law (“SCL”) and Recommended Practice 29 by the Association for the Advancement of Cost Engineering (“AACE”).

Standard delay analysis methods employed in the industry include:

  • Impacted As Planned;
  • Time Impact Analysis;
  • Time Slice Windows Analysis;
  • As-Planned versus As-Built Windows Analysis;
  • Retrospective Longest Path Analysis; and
  • Collapsed As-Built Analysis.

Nevertheless, two primary concerns arise:

  1. While the guidelines contribute to minimising procedural subjectivity, there’s a growing tendency to excessively rely on them as if they carry the weight of local legislation. Such reliance is unwarranted, given the explicit statements by both SCL and AACE, emphasising that they function solely as guidelines. The foremost reference should always be the contract and its stipulations.
  2. The interpretation of facts, underlying assumptions, and the application of methods exhibit significant variation. Both SCL and AACE recognise that delay analysis ultimately relies on common sense, professional judgment, and the expert opinion of the delay analyst. This involves numerous subjective interpretations and decisions, underscoring the importance of transparently exposing assumptions and justifying opinions.

The Most Appropriate Method

Regardless of the method’s name or category, the essence lies in the execution of the analysis and the articulation of the process. The 2019 judgment by Justice Hammerschlag in White v PBS1 underscored the importance of focusing on common sense and the contemporaneous evidence of cause and effect rather than adhering solely to a widely accepted method or expert opinion. The judge stated that “the fact that a method appears in the Protocol does not give it any standing, and the fact that a method, which is otherwise logical or rational, but does not appear in the Protocol, does not deny it standing”.

The White v PBS judgment emphasised that the appropriate method is to determine the matter by paying close attention to the facts, and assessing whether it can be proved, on the probabilities, that the delay events(s) delayed the project as a whole and, if so, by how much.

In conclusion, it can be asserted with confidence that there is no universally applicable method. The industry offers multiple generally accepted methods, each potentially most suitable in specific scenarios. It is crucial for the delay analyst to acknowledge and address the shortcomings inherent in each selected method.

While it is prudent to follow industry practices and utilise one of the delay analysis methods endorsed by SCL and/or AACE whenever feasible, it remains essential, in every case and irrespective of the chosen method, to establish causation and provide explanations for:

  • The factors influencing the selection of the delay analysis method(s);
  • The method itself, its application, and how the analyst has addressed its limitations; and
  • The factual basis, instructions, interpretations, assumptions, opinions, and conclusions.

Factors to Consider

Numerous considerations come into play when selecting and executing delay analysis, encompassing:

  • Contractual provisions regarding delay analysis, progress, programming, causes of delay, and extension of time;
  • The state of the works during the periods of delay and at the time of analysis;
  • The intended purpose of the analysis;
  • The accessibility and reliability of project records and schedules;
  • The nature of the delay events;
  • The complexity and scale of the issue;
  • The financial implications and budget allocated for the delay analysis task; and
  • Other project-specific intricacies.
    In my view, evaluating these factors is as crucial, if not more so, than the actual execution of the delay analysis.

Additionally, it is imperative to incorporate the analysis and conclusions regarding these factors into the comprehensive delay analysis package. This package may encompass programs, narratives, spreadsheets, and other supporting documentation, collectively forming the delay report.

[1] White Constructions Pty Ltd v PBS Holdings Pty Ltd [2019] NSWSC 1166

About the Author

Yazeed Abdelhadi


Yazeed is a professional consultant with over 17 years of experience in the construction and engineering industries providing planning, project controls, project management, forensic delay analysis, claims management, expert witness, and commercial services to clients in the Middle East, New Zealand, Singapore, Cambodia, and Australia.

Yazeed specialises in commercial claims and forensic delay analysis and has been appointed as an expert witness in a number of adjudication and international arbitration matters. In addition, Yazeed is the author of a number of publications on delay analysis and often speaks at public events and conducts training on planning, delay analysis and claims to clients.

Further, he is the current Vice President of AACE Australian Section and the Lighthouse Club Australia.

For information about delay analysis methodologies


This article aims to offer insights into the prevailing industry practices related to delay analysis. Nonetheless, it should not be construed as legal or professional advice in any form.