The information problem.
WHAT USUALLY DELAYS WORK
Waiting for something from the client.
WHY IT HAPPENS
Requests made piecemeal No deadline attached Unclear what is actually needed The client does not have it either
WHAT TO DO
Request everything at once, in a single list Explain why each item is needed Give a deadline Explain what happens if it is late
THE CONSEQUENCE STATEMENT
"We cannot start until we have these, and the timescale moves accordingly."
Stated at the outset, that is fair rather than aggressive.
WHAT TO MAKE EASY
Supplying it. A form, or a folder to upload to.
FOR CONTENT
The single most common cause of stalled projects.
Decide early who is producing it and price accordingly.
WHAT TO CHASE
Politely, and on a schedule, not only when you are blocked.
WHAT TO RECORD
What you requested and when.
WHAT TO DO IF THEY CANNOT SUPPLY IT
Offer to produce it, as a chargeable addition.