Contractor controlled schedule items...

Member for

16 years 3 months

Long lead times can vary during these times of the supply chain shortage. Another factor may be the price that the contract is willing or wants to pay. Maybe paying more can get the long lead item here sooner. But that is his call so the owner is stuck with it. 

I think you see contractors getting their way more commonly because an owner can not dictate means and methods. 

The people who are signing off on the chnages to schedule specificaitons must have the authority to do so and should check with the specfiicaiton writer prior to signing off on the changes to determing if the changes are acceptable.