The purchasing officers are always complaining that it's too long before they 're told about sales orders.
采购人员总是抱怨，他们得知销售订单的时间太晚了。
英语百科
Sales order
The Sales order, sometimes abbreviated as SO, is an order issued by a business to a customer. A sales order may be for products and/or services. Given the wide variety of businesses, this means that the orders can be fulfilled in several ways. Broadly, the fulfillment modes, based on the relationship between the order receipt and production, are as follows: