From what you have described, it sounds like an event occured which prevented working for the last hour of each day, which was a CE. This occured on 12 occasions. I can see why the effect would be difficult to assess, although it looks like the quotation was based on the value of lost time, with a corresponding time assessment. It now looks like the actual effect on the progress of the works is different to what has been implemented.
Although the PM may feel 'aggrieved' by the outcome, they are an intrinsic part of the CE procedure and whatever was implemented would have been with their input. Clause 65.2 (under NEC3) also seems to say that if you estimate something in advance within your assessment and the subsequently recorded outcome is different, then the original estimation is not changed. If this event occured on 12 separate occasions I am surprised that there was not a 'learning curve' to assess the affect of the event and understand the implications each time. This understanding could then have been used to assess subsequent CEs.
The problem with working hours is that productivity is not just related to actual time on Site but a number of other factors. Also, measuring productivity on a construction project is difficult because the schedule baseline is usually a 'best guess' and may even be worked backwards to fit a specified Completion Date. It is clear that the PM may feel like an injustice has occured, but if matters have been concluded under the contract then it should be a case of looking forward not backwards.
Although the PM may feel 'aggrieved' by the outcome, they are an intrinsic part of the CE procedure and whatever was implemented would have been with their input. Clause 65.2 (under NEC3) also seems to say that if you estimate something in advance within your assessment and the subsequently recorded outcome is different, then the original estimation is not changed. If this event occured on 12 separate occasions I am surprised that there was not a 'learning curve' to assess the affect of the event and understand the implications each time. This understanding could then have been used to assess subsequent CEs.
The problem with working hours is that productivity is not just related to actual time on Site but a number of other factors. Also, measuring productivity on a construction project is difficult because the schedule baseline is usually a 'best guess' and may even be worked backwards to fit a specified Completion Date. It is clear that the PM may feel like an injustice has occured, but if matters have been concluded under the contract then it should be a case of looking forward not backwards.