Why does the man postpone the project?

M: so I think we will have to delay the start of our warehouse expansion until next week. Some of the building materials haven’t arrived from the supplier yet, and they are essential to the project.
W: That’s a shame. I’ll call the suppliers today and arrange to pick them up on Thursday. I have a meeting in that part of town, so I can get them on the way back.
M: Perfect. We also need to get in touch with the contractors and tell them not to come until next week. Would you like me to do that?
W: If you wouldn’t mind. I’m a bit busy this afternoon. Hopefully, we can make up for lost time and still get the project finished on schedule.