OneDrive, Microsoft's file sync app formerly known as SkyDrive, lets you store your files online, edit Office documents in the free Office Web Apps, and easily access your online files from your PC.
File signed supplier agreements with proof in the supplier folder.
Keep signed supplier agreements and their signing proof together in the right supplier folder, so your team can find both when needed.
Name missing supplier contract files on the approval request.
Your requester sees exactly which contract files are missing, while the approval stays in correction for follow-up.