Kanban Rule #5: Defects and incorrect amounts are never sent to the next downstream process.
Applying this rule in your studio: if there is a problem, it gets stopped immediately! Never send a product with a problem further down the process where it could possibly end up in the hands of your customer. If defective products stay in the kanban, your next process won’t have the right number of correct items. Defective problems should get flagged immediately and removed from the production floor and dealt with totally separate from regular production.