How to manage outsourcing parts for machining?

In fact, supplier quality management is a big subject. I do design, but in accordance with the quality management process, I have also participated in many of them. I will discuss our company`s approach from my perspective: supplier audit, which is to be done before starting business. The purchasing department provides several alternative companies. Quality, engineering, and procurement three companies will visit together to review their quality management. Process, processing capability, company size, turnover rate, technical level, design capability, environmental protection, personnel safety, etc. Finally, give a conclusion, what difficulty level products let them do. Provide product inspection report for each batch of product delivery, and investigate process control documents when quality problems occur. Usually, they will check their quality documents from time to time. If the documents are falsified, the cooperation will be terminated. Engineering communication, drawings are fundamental and have legal effect. Quotation is based on drawings, processing is based on drawings, and acceptance is based on drawings.

To be fair, when quoting, the supplier has the right to mention DFM (design for manufacture), which means that if the drawing requires them to fail to do so, it must be submitted when the quotation is made. Don`t mention it at this time, and start to do it later. No more. The delivery date should also be given at the time of quotation, and there should be a written commitment, and no deduction can be made. Generally, suppliers will leave enough margin for themselves. Therefore, when sending out an inquiry, generally purchase enough time in advance to ensure that DFM and the supplier arrange production. The control of the processing process and the factory inspection are done by the supplier, and the acceptance and re-inspection is usually only a small amount of random inspection. Once you find out-of-tolerance or scratches and other defective products, increase the sampling ratio. This sampling method is specifically introduced in the quality management. Crushing suppliers is not a long-term strategy. Training should be given to them regularly to help them grow. In some design stages, suppliers are involved as professional consultants in production, so that they can get the order in the design stage. The formation of a mutually beneficial relationship in this way is good news for itself and its suppliers. This is how the business is accumulated.