How does NEC4 clause 62 work?

Clause 62 is the quotation stage, and it runs to a timetable that both sides can lose by ignoring. Under clause 62.2 a quotation comprises proposed changes to the Prices and any delay to the Completion Date and Key Dates, with details of how the Contractor assessed them and, where the programme is affected, alterations to the Accepted Programme showing the effect. The Project Manager may also ask for quotations for alternative ways of dealing with the event. Under clause 62.3 the Contractor submits the quotation within three weeks of being instructed to do so and the Project Manager replies within two weeks of the submission. The reply is an acceptance, an instruction to submit a revised quotation, which under clause 62.4 must state the reasons, or a notification that the Project Manager will make its own assessment. Clause 62.5 allows the periods to be extended if the Project Manager and the Contractor agree before the period ends. Clause 62.6 supplies the remedy for silence: if the Project Manager does not reply in time, the Contractor may notify the failure, and if the Project Manager still does not reply within two weeks of that notification the quotation is treated as accepted. The money in the quotation is assessed on the rules in clause 63, so it is a forecast of Defined Cost plus Fee, not a claim built from invoices. The time element sits with the programme and the programming expert, not the quantity surveyor. Three failures recur. Quotations go in as a bare total with no details of the assessment, which invites an instruction to revise. Extensions are asked for after the period has expired, when the clause no longer allows them. And Contractors who receive no reply wait rather than notifying the failure, so the deemed acceptance never runs and the quotation sits unpriced until the final assessment.