What is QS role in Extension of time (EOT) in construction project & how to prepare EOT?

to prepare valuation for preliminary items as below

Preliminary items can be group to different categories of initial ,final cost , time related charges, cost related charges or combination of types.

Proportion per month.

Dividing total preliminary by number of months in contract period, giving constant amount for inclusion in each valuation. But this does not take in to account if work may be behind program, which could result total preliminary  bring paid before complete.

Percentage of value.

Preliminary are expressed in % of contract sum to be added to  monthly value of contractor measured work.

In both this and previous method  prime cost or provisional sum in preliminary should be deducted before proportion.

Detailed breakdown.

This is best method having all details.

Example:

Supply and operations of track mounted crane.

This may cover

Base ( put down labour and material (initial cost)), take up and remove ( final cost))

Track (( laying ( initial cost), hire ( time related cost), remove ( final cost)).

Transport ( ( to site( initial cost), from site( final cost)).

Fuel cost electricity ( time related cost)

Operator ( time related cost)

Temporary electric supply ( bring in ( initial cost),remove ( final cost))

 EOT is based on the actual  days by which a certain project is extended on  impacting the critical path activities... for the reasons attributable to the Client. 

Calculating EOT is same as calculating the overall cost in completing the  task or contracts. The  only difference here is the cost loading would be only for extended time and delay like  cost of material , extension ,  Tools and plants , man days , fuels , overheads, escalations, ideal charges, operational cost, legal fees, HR and Ho cost ,admin cost etc.

To proof, to substantiate  and to certify EOT is  a complex job but no other remedy to it,

EOT is to be calculated based on the actual Man Hours inquirred to carry out a specific task, the transit time required if any out of stock items to be delivered, and the additional time required based on the available resources (Manpower, Pl & tools etc)