We can't get access when we were promised it
Areas aren't ready, possession slips, and there's no record tying the delay to the party that caused it.
What's happening?
The programme assumed the area ready on the date; the date came, the area wasn't, and the gang stood, got redeployed at a cost, or the work was resequenced around the gap. It happens a dozen times on an ordinary job - and mostly it goes unrecorded, because everyone's energy goes into working around the problem rather than writing it down.
Later, the account needs exactly that record: which area, promised when, given when, what stood or moved and what that cost. Without it the costs are real but orphaned - absorbed into prelims and disruption nobody can attribute. The log is the discipline: promised dates in, actual dates against them, the effect noted while the week is still fresh. What the contract does with those facts varies; having the facts is what makes any route usable.
The solution
Promised dates against actual dates, kept as they happen.
If you would rather it were done for you, Variation Issuing & Registers is the service that does it.