Should an accepted programme be updated before evaluating an EOT

use the contemporaneous schedule meaning the schedule that in effect at the time of the delay. So its in the same period of time as the delay.

Thanks Zoltan,

My problem there is that this was an instruction to consider and forecast the effects of C19 on the project, for 3 months into the future. There was no delay as such, just a possibility of a delay that if we could demonstrate our reasonable assumptions, like social distancing causing inefficiency, then the EOT would be granted. The problem arises becasue the assesment is now taking place so long after the instruction, there is the benefit of hindsight, as we are now 6 weeks into what we were asked to forecast. The reality didn't pan out as forecast, for other reasons, but at the time of the instruction, our forecast was true and genuine.

They are trying to use the knowledge of hindsight to minimise the EOT we were asked to provide.

I hope that makes sense?

Since the reality didn't pan out as forecast, for other reasons, but at the time of the instruction, our forecast was true and genuine.

Then I guess you have to ivestigate the for other reasons" aspect of it. If you have the benefits of the hind sight then you will have to show the planned delay vs the actual delay. 

figure out your inefficenecies using the measured mile approach this will give you a percent inefficent and use that to forecast durations from there ending up with the total delay.

The contract and the way delays are assessed at law can vary. 

Your primary issue is defining the actual delay caused by the event, and as a secondary issue your entitlement to compensation for the delay. 

Defining the actual overall period of delay may (or may not) benefit from a contemporaneously updated schedule, good practice such as the 'Delay and Disruption Protocol' recommend an update immediately prior to the delay commencing. 

Defining the atual effect of the delay event on your work cannot be done without first removing the effect of delays caused by other factors including by you.......  If you don't do this and the issue becomes a dispute the other sides expert certainly will. 

Overall this is a highly complex area and I would strongly recommend collaborating over disputing (regardless of your interpretation of the contract).  For more on this see: https://mosaicprojects.com.au/PMKI-TPI-080.php