Your question states that the machine was introduced some time in to the contract. Was it introduced with the expressed intention for it to be used to assess the PWDD. If it was then you need to check what was prescribed.
I presume that the PM is disallowing the cost that is in excess of the clock-in-machine on the basis that in his opinion the amount is not justified by the Contractor's accounts and records.
You will therefore have to substantiate your cost records to prove they are correct.
I presume that the PM is disallowing the cost that is in excess of the clock-in-machine on the basis that in his opinion the amount is not justified by the Contractor's accounts and records.
You will therefore have to substantiate your cost records to prove they are correct.