What happens if the planned completion date ( milestone ) is not on critical path, say it has total float of 30days , then later as works progresses a CE is implemented which impacts on the planned completion date by reducing its float from 30 to 15days i. e still not on the critical path ??
In simple terms the planned Completion Date should be on the critical path. Assuming you are just showing that you are planning to finish everything early by 30 days, then within the planning software I would have created an activity of 30 days that plugs the gap between planned Completion and Completion Date and called it “terminal float”. Once logic linked this will make the planned Completion on the critical path.
Any assessment of a compensation event is measured against planned Completion. If your planned Completion is affected by a CE then you move Completion Date by the same amount. Contractor owns “terminal float” which is explained within clause 63.3 (particularly well in the guidance notes of that clause).
In your example here Completion Date should be moving by 15 days, and your compensation event you are entitled to assess “prelim” type costs (that would otherwise not have been incurred) within the quotation for you being on site an additional 15 days longer than you needed to be due to the effects of that compensation event.