under the certificate issued on 13 June, 2003.) And yet the statement at completion referred to in clause 60.10 of the contract was not issued within 84 days of the issue of the Taking-over Certificate. So also, no final statement was issued within 56 days of issue of the Defect Liability Certificate. What was issued at that time was a running account bill, being R.A. Bill No.67. The Petitioner not only accepted this interim bill, but the same was even certified by the Engineer by way of an interim payment certificate, namely, IPC 69A and 69B. If that is so, it is clearly reasonable to hold that both parties mutually did away with the requirement of clause 60.10 and waived the same. The claimant, thereafter, submitted what it termed as draft final bill on 22 July, 2003. Even if one were to treat this as a draft final statement under clause 60.11 of the contract, what the contract contemplates is that after this submission, the Engineer and the Contractor would consult each other, during which consultation, further information or changes in the draft, as may be required by the Engineer, would be made by the Contractor, and finally, the parties would reach a stage where there is an agreement between them on the sums to be paid to the Contractor or they arrive at sums, which they agree and other sums, about which there is a dispute. If there is any dispute, the Engineer is required to submit an interim payment certificate for those parts of the draft final statement, which are not in dispute. It is only then that the disputes are required to be settled in accordance with clause 67 of the contract, that is to say, by arbitration. As noted by the arbitrators, the consultation stage itself clearly lasted till about March 2006. The stage of agreement on those parts of the draft final statement, which were not in dispute, could be said to have been arrived at when the Engineer's decision reached the contractor. Even at