Analysing Data

DD Quantum Expert

DD Quantum Expert:
- The DD App


Robert Gemmell

T: +61 7 3012 6421

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DD Quantum Expert

DD Quantum Expert:

1. Has designed and developed the DD Quantum Expert App ("the DD App")

The DD App quantifies a contractor’s entitlement to delay and disruption costs from the data inputted into the App by the App user.

The DD App guides the user of the App, step-by-step, through entire quantification process. 

The DD App is designed for anyone who needs to quantify delay and disruption costs, plus the package caters for anyone who simply just wants to learn and / or just needs to know how delay and disruption costs are quantified. 

The guidance on the DD App also provides detailed explanations as to why the calculations are conducted in the manner being carried out.

The DD App user is able to print all the calculations and graphics in a way that is presentable to who will finally assess the delay and disruption claim.

So, why the DD App? Robert has spent over 25 years in the construction and engineering industries, much of which has been assessing contractors’ entitlement to delay and disruption costs, its what Robert specialise in either as expert witness, advisor or deciding delay and disruption disputes as a dispute decider – many, if not most, of the contractor’s submissions for delay and disruption costs are not prepared as well as they could be and hence do not persuade whoever is assessing the claim – and as a result many contractors just don’t recover the sums of money they are entitled to – and often these sums are many millions or much more…

To remedy this, Ray and Robert have designed the DD App - a tool that users can use to quantify, or simply learn how to quantify, a contractor’s financial entitlement to delay and disruption costs.

DD Quantum Expert conducts ongoing world-wide research on the quantification of delay and disruption costs. The research is posted on the research page of this website which is continuously updated.

The DD Quantum Expert website also provides a library page.  

The library page lists and provides a summary of the cases and guidance notes that are applicable to each head of a delay and disruption claim plus more.

The library page is continuously updated. 

The DD Quantum Expert website also provides a blog page.  

The blog page provides all the articles that Robert Gemmell has posted on LinkedIn. 


Key People

Robert has over 25 years of experience in the construction and engineering industries and is named in the Who’s Who Legal: Consulting Experts Guide, 2018, 2019, 2020 and 2021 as a leading expert and 'Thought Leader' in the field of construction delay and disruption.

Robert specialises in the quantification of contractors financial loss caused by delay and disruption to the progress of the works and Who's Who Legal says “Robert Gemmell stands out for his deep understanding of delay and disruption costing and for his high-quality outputs" and is cited as "an expert of choice on large disputes".

Robert has given evidence under oath in court proceedings and has undertaken more than 100 appointments as Arbitrator, Adjudicator and Expert Determiner.

Robert is the author of the book entitled “Quantification of Delay and Disruption in Construction and Engineering Projects” published by Thomson Reuters. The Hon Justice Peter Vickery says the book is a " of legal scholarship and authority ... Robert Gemmell’s text book is as comprehensive as it is valuable, providing as it does a practical guide to the critical exercise of quantification of the loss..."

Robert is also a Senior Fellow of Melbourne Law School, the University of Melbourne.

Contact Robert: 


Raymond Choong

Ray is a full stack and a software developer who has a Bachelors of Business Computing, a Masters of Advanced Business Practice and a Masters in Business Administration. 

Ray has also obtained the following licenses and certifications: Microsoft exam 480: Programming in HTML5 with JavaScript and CSS3, Microsoft exam 486: Developing ASP.NET MVC Web Applications, and Coursera course certificate in Usable Security. 

Ray is highly motivated by the opportunity to do meaningful work, and to contribute wherever he can to a greater good.

As a software developer, Ray's objectives are simple, which is to build software that can make a difference to the stakeholders. That he can look back at the end of a software project with pride and say "Well, I was part of the team that developed it."




“We engaged Robert on a major bridge construction project as an expert to assess an extension of time and delay cost claim and to give some commercial advice. Dealing with an extremely complex deed and under a delivery partner model, Robert was able to defend our entitlements, providing us commercial advice in the first stage of our design & construction contract in order to deliver a very successful project for all the parties and stakeholders”

Project Director - International Infrastructure Contractor


DD Quantum Expert Proudly Supports 'Cycle the Nation'

A proportion of the profits from the DD App is used to fund future Cycle the Nation events.  

​Our cycle events are a 100% volunteer effort and to date have raised over AUD$400,000 - we’re aiming to substantially add to that amount over the next 5 to 10 years – or longer if our legs can take it!

For more information, please visit Cycle the Nation website: