Earning value from my studies

A situation arose at work recently. One of our partners, upon whom we have some key dependencies, notified use that some dates in one of their projects and moved back.

Looking at the information provided I was struck that delivery of the first milestone had slipped by 5 weeks. This was because the work had taken longer than planned - remotes working and COVID-19 restrictions had played a big part in the delay. All the subsequent milestones were now predicted to move back by the same amount.

As I looked at this what came to mind was my recent reading on this Earned Value. It didn't feel credible that the subsequent milestones just move back. That would assume that only the first phase of work would take longer and all subsequent phases would adhere to their original planned durations. But COVID-19 restrictions and remote working continue to be in place - and with predictions of a second wave may get tighter. What would feel credible is for the duration of each phase to be extended by a proportionate amount and the end date of the project to move back further than 5 weeks.

This was again brought to mind when reading Schon and his concept of reflective practice and the difference between earning-on-action and learning-in-action.  In this situation I have demonstrated both.  Learning about the concepts of earned value and doing theoretical examples for a TMA (on-action) versus the dynamic reflection in the midst of action when faced with an emerging situation (in-action).  

References:
M815 - project management - earned value
TU812 - Systems Thinkers - Schon