What to do if customer's complain. First you must collect information about product's quality problem. Beside pay attention to soft of information, Some kind you must collect. Of course, Information of collection must pay attention to speed and correction. Then you depend on these corrective information to analysis. If you analyze correction to deal with the market production. Your enterprise loss few. If you analysis wrong. Your enterprise loss very high. So you must study to research market quality information, If customer complain quality problem, Let your company loss very few.