Sub-supplier process quality control issue

Support Quality Investigation to identify root cause,
containment, and corrective action.

Japanese automotive company

Japanese automotive company finds a defect in their assembly line, contacts their Korean supplier and Asia Manufacturing Services to rectify the problem immediately. The problem identification, containment, and corrective action was performed in 3 days starting on a Saturday.

That weekend, Asia Manufacturing Services was contacted to support the problem analysis, ensure a containment action was effectively implemented and work with the Korean supplier to define and implement a permanent corrective action. A joint teleconference was held to clearly define the current problem as it puzzled everyone. An action item from the teleconference was to visit the Korean supplier's facility to determine what had changed in their process as previous shipments were OK. Initially touring the supplier's facility, it was evidently clear nothing in their process changed and even if it did, there would have been no impact on the current state problem.

The next step was to investigate their sub-supplier's facility. Upon initially reviewing their manufacturing processes along with a weak Quality Control Plan and PFMEA, it wasn't clear as to where this defect could have been injected into the process. However, observing the process over several hours, there was a technique involved in mixing certain chemicals that was not fully defined in the work instructions.

Upon reviewing some historical process documents and time cards, it was found that for one batch the mixing operator left the company early that day and someone else mixed the batch of chemicals. An experiment was conducted and the results yielded an exact match to the current state problem. Several actions were immediately taken to identify and quarantine all parts within that batch, immediately start a replacement program to re-fill the supply chain, update the work instructions, PFMEA, control plan, identify the work station with a Quality Alert, update the skills training matrix, re-train all shift operators in the revised work instructions, develop a report for the Japanese customer, then present the Quality Issue to the Japanese automotive customer with samples of parts and photos.

From initial customer defect identification in Japan to their Korean supplier, to their sub-supplier, the root cause, containment action, and corrective action was performed in 3 days starting on a Saturday.