Project sales conservatively but make sure not to under perform sales. Balance.
Look 20% of the customers do 80% of the business. You know that. Now what are those guys going to do this next twelve months? Really - c'mon. If you have salespeople - review with them and really work the sales people for real and detailed forecasts that you roll up. And do it quickly. It's doesn't take long when you focus, delegate, and monitor.
Whether you have salespeople or not you have to get a resonable sales plan together and project it out. There's no cash flow without a sales plan.
Face the music on collections Tell it like it is.
Probably some of the money is what bankers call "concentrated", meaning a few customers may owe you a disproportionate share of your collections, and if they pay slow - you have to as well. So you have to look at some of the components of what is owed to you - it's not just one spread of jam.
Maybe you have some history from you AP system. Maybe not, but you gotta think about the reality of collections into the furture with some of your customers seeing losses and slowing payments as well.
Include all the expenses - don't make new ones up and don't ignore any expense either.
At the end of the day the expense are real. You may have to cut some expenses or even a lot to get through the real sales you projection and their resultant collections. But hey - lot's of people have been through this for time in memorial and it's worth it. When you get through you'll have a healthier company that makes more money and provided jobs to you and your family and many other family units as well.
So be pretty thorough about the expense. It makes sense - don't dream them up in a scare fest, but don't overlook, don't estimate low when it's higher, and don't pretend.