Where a project team has several CEs to assess and some are very old and complicated/hig value to assess, but others are very simple. Is there anything in the NEC3 ECC terms, that dictates which order the CE are assessed in? ie Can the most recent and simplest CEs be assessed now while more thought is given to the older and more complicated CEs?
In the absence of any agreements, it is according to the timescales of the contract, which is kickstarted from when they are notified (assuming the Contractor notifies those that are down to him within the 8 week timebar of clause 61.3).
However, under 62.5, both the time to submit a quotation and the time for the PM to reply can be extended by agreement provided that it is agreed BEFORE the quotation / reply is due and the PM notifies this agreement. Otherwise, strictly speaking, a supplemental agreement has to be agreed between the Contractor and Employer to vary the conditions of contract.
However, I would point you in a different direction to that indicated in your question : wherever possible sit down and work through the consequences of large complicated CEs ASAP as these are the ones which will cost you especially if not managed. If the PM can give the Contractor clear direction on the outcome wanted, then the Contractor can programme and work more efficently with less risk leading to certainty and a better value quotation for the Employer and a bit of extra profit for the Contractor. Indeed on one contract with huge amounts of change they did just this and agreed to let the historical small value CE quotationa drift a bit while they managed and pre-priced the stuff that mattered. The result was that while the Prices went up from £6.5m to £13.5m, both parties thought they saved a lot of physical cost and, as the final account was agreed on the dot of Completion, an awful lot of legal costs.
I would add to Jon’s valid points and suggest that in very simple terms for both practical and contractual reasons you have to assess events in the order that they occur. You can not really assess them out of sequence as it may change the result. For example, you could assess CE02 without first assessing CE01 as it is viewed more straight forward. It may have no affect on planned Completion. However, if you first assess CE01 and THEN assess CE02 it may be that it now affects the planned Completion and hence you would be able to claim a delay to Completion Date.
Having said that there is nothing to stop you assessing a more recent CE if it is clear that it would not affect planned Completion in any eventuality – as you can just assess the Defind Cost of that item and other CE’s will not affect the assessment in any way. Trouble is it is often difficult to say if preceding events might affect later ones unless you assess them in order as intimated below.
In my experience however difficult it is to assess a CE now, it will always be harder and more subjective to assess it later on in the project – so you might as well agree it now and move on. As Jon suggest there are timescales to follow for individual events to be assessed, although certain extensions can be agreed along the way where warranted.
It is up to both Parties to try to keep on top of this process so that both Parties are clear where they stand through out the project in terms of liability of both final cost and the agreed Completion Date. Not saying it is easy when you have a large number of big changes but the alternative is more subjectivity and uncertainty in either Parties liability. Contractors should make sure they keep on top of the revised programmes issued for acceptance and to ensure CE quotations are realistic and timely. Project Managers should ensure they keep on top of the formal acceptance of the revised programme and do their part to be assessing quotations timely and where necessary assessing themselves.