The article outlines the steps to add a SKU number to a product without one, or change the current SKU number of a product.
FOLLOW STEPS BELOW:
1. Open Product Costing window
2. Search and filter to product you want to add/update SKU
3. Ensure product is in an editable status
4. Right click and select 'Edit Sizes/Units'
5. Enter or replace desired SKUs
6. Close Job Size Matrix window
NB. For a quick tutorial watch below