NEC3 ECSC: Under short contract, can the Contractor change supplier / manufacturer for specified items?

If the items are specified in the Works Information to be supplied by a particular supplier / manufacturer then you will have to comply with the requirement otherwise the items could be classed as a Defect (part of the works not in accordance with the Works Information).

However, if there is a problem with obtaining the items from the specified supplier / manufacturer e.g. they’re out of stock and if you wait for them to come in stock it will make you late, then you should send and early warning notification to the Employer under clause 16.1. You can then propose alternative suppliers / manufacturers who have the item in stock. If the Employer accepts the alternative then you need to consider if this is a compensation event under clause 60.1(1) which may entitle you to additional cost and time.