Hi,

You're encountering a common problem in Odoo where partial shipments and unit of measure (UoM) conversions (like Nos to Ton and back) lead to cumulative rounding errors. This results in the system showing a slightly lower received quantity (e.g., 4,999.9999 instead of 5,000) and a phantom backorder that can't be fulfilled. The root cause is that Odoo uses floating-point numbers, which have inherent precision limitations, and these errors accumulate with each conversion.

Several solutions exist, ranging from simple configuration tweaks to more complex code modifications. A quick fix is to increase the decimal precision for product quantities in Odoo's settings, but this only postpones the problem. Manually adjusting the received quantity on the final receipt can clear the backorder, but it's not scalable. The most robust solution involves modifying Odoo's code to apply proper rounding at each step of the UoM conversion process. This requires development expertise but prevents cumulative errors. As a last resort, consider using integer quantities if your business allows it. The recommended approach is to implement automated rounding in custom code for a long-term, accurate solution.