Below is high level requirements. Will provide a spread sheet with additional requirements.
a vendor registration
b vendor login
c Vendor Profile (Update)
d Order summary page (Poll)
e Order detail page (Print)
e.2 Decline order; page
g Send Order wizard
Select delivery date and item code for up to 5 item; add more items button adds another 5 lines
Enter Order details
Payment page (if payment is required)
g.1 Exchange messages
h Monthly financial debit and credit statement
A script to post fees on the vendor accounts
j Cron Scripts
A cron script to jump orders in case of multiple vendors
A cron script to allocate orders based on allocation rules
k Order allocation
Send order ack emails
l vendor catalog
Add/update product
categorise products