Cost & AR revenue problem

Q1. my company is a marketing company ,finance dept. have

to place an invoice and bill to department store every 3

month ,but sales input sales orders into SAP system and

post good issue everyday , cost account will be create

when post good issue .how to put cost and A/R in the

same month or balance both ,tks

Q2. another one , goods will be delived to customer once , but

the payment are separated in different month ,for example

7/1 sales order creation , 1000usd

7/3 post good issue and create cost account

7/20 payment 200 usd

8/20 payment 500 usd

9/20 payment 300 usd,

How to balance between cost and A/R revenue

thanks very much