The Projected Shortages Report (IPSR) shows when shortages will occur given current supply, demand, and commitments based on a date you specify. For each item, the report calculates:

• Supply: The sum of open quantities on purchase orders, manufacturing orders, and incoming transfers. Requisition and/or planned order quantities are included in supply if you select the Include requisitions? and/or Include planned orders? program options.
• Demand: The sum of quantities to be used for manufacturing orders, sales orders, and outgoing transfers
• Balance: Beginning balance + Supply or Beginning balance - Demand

And reports:

• The date on which the balance goes to 0 or less

• Next supply order (i.e., the first order due after the shortage date) with the quantity, date and other details (buyer, planner, etc.)

Here's a sample report for Planner VCM: