standard
defect classification
defects are generally classified into 3 levels:
1. critical - defects that will affect end-users' safety
2. major - defects that will NOT affect end-users' safety, but the products may result from lost in functionality or it's cosmetic defect will affect its saleability
3. minor - defects that are usually regarding to its appearance & workmanship, and these defect will not seriously affect the overall function of the product