This post was compiled by Kobus le Roux for Le Roux Consulting and published on the internet on 16/05/16.

So today I’m taking a swipe at this very controversial and difficult topic: How to calculate the impact of delay on a construction project. I could provide you with the most technical expose of Delay analysis techniques (DATs) that will leave you exhausted, hanging on to your screen by the threads of your eyelids. But having experienced the technical struggle out there in the industry and the glaring expanse of excuses for why an adjudication of delay cannot take place I thought it best to start with this simple guide for dummies on how to calculate the effect of delay.

Dummies, for the purpose of this article imposes no indignity as it refers to professionals without any formal DAT knowledge or experience. Don’t feel bad if you classify as a dummy under this definition, research in a portion of the industry in South Africa has shown that almost 100% of the professionals, who traditionally take on the role of principal agent, has no knowledge or experience in using any of the formal methods for delay calculation (DATs).

The steps outlined below takes place only after you have reviewed the claim under the terms and conditions of the standard form of contract. These steps only apply to the physical action of analysing delay. Don’t despair if it does not make sense at first, I will provide some examples later on:

Step 1.

Throw away the programme/construction schedule… momentarily.

Step 2.

Review the delay in isolation from the programme:

Write down the date and circumstance that gave rise to the delay
Determine the reasonable impact of this circumstance measured in duration.
Determine the reasonable duration of any successors to complete the project, i.e. any activities that can only take place after the impact of the delay has completed or played out.

Step 3.

Obtain a date from the exercise you did in step 2. Measure that date to your current contractual milestone or completion date. If your date is earlier than the contractual date, the circumstance did not impact on the end date and therefore a critical delay did not take place… award 0 days. If your date is later than the contractual date, the difference in working days between the dates is the calculated impact. Award this amount of days and revise the date as per your calculation.

Step 4

Now take out the programme again and continue with your project.
You don’t believe me do you? Let’s test my method:

You have a ten-month project. A 20,000 activity construction schedule.

Delay circumstance 1:

At the beginning of month 2, excavations must go deeper than anticipated and as a result the concrete bases and columns are also enlarged.

STEP 1. Put your 20,000 activity schedule aside.

STEP 2.

Month 2 is the delay start date
2 Weeks standing time waiting for revised drawings
Two (2) weeks’ additional duration in excavations
Bases and column enlargement caused a reasonable 1 month’s additional duration
The remaining 19,990 successor activities can only take place after bases and columns, and the reasonable duration for this is 8 months.

STEP 3.

From month 2 we add 2 weeks for standing time, 2 weeks’ additional work for excavation, 4 weeks for increase in columns and bases and 8 months for the remaining successor activities. (2+0.5+0.5+1+8) = month 12. That is a difference of 2 months. If all my calculations under step 2 are reasonable, the circumstance caused two months’ delay on the completion date.

Delay circumstance 2:

In month 8, a VO is issued for additional equipment that was not part of the original tender.

STEP 1. Put your 20,000 activity schedule aside.

STEP 2.

Month 8 delay start date
1 Month duration for procurement of new material,
Two (2) weeks’ installation after it gets delivered,
1000 activities can only take place after we have installed this new equipment and the reasonable duration for this string of successor activities is 1 month.

STEP 3.

From month 8 we add 1 month for the delivery, 2 weeks for installation and another month for the remaining successor activities = month 10.5. That is a difference of 0.5 months. However, if we take circumstance 1 into consideration our new completion date is month 12. Therefore 10.5 < 12 = no critical delay caused by the new equipment VO. Now where did I put that schedule again?