For each delay event, the Contractor must serve notice within 28 days of each event in accordance with sub-clause 20.1 “Contractor's Claims” , the Contractor must maintain the contemporaneous record and the Engineer will review and comment on the records prior to submission of the claim. In each project, the engineer does not act as an arbiter and does not adequately review and investigate the subcontractor's contemporaneous records. They simply reject subcontractor claims considering subcontractor delays which may not be the sole cause of the total project delay. However, even if the deadline extension is approved, the appropriate actual cost of the extension for the approved deadline extension is not approved. the quantity is increased by more than 10% which will be multiplied by the relevant rate agreed in the bill of quantities and this value increase by 0.01% of the contract value in such a scenario the new prices must be agreed for the relevant item in discussion with the engineer and this must be adjusted to the contract amount. But most of the special conditions of the contract, the Engineer deletes this clause to favor the Employer.• Value