When conducting a third-party audit to ISO 9001, especially in the context of training and corrective actions taken due to customer complaints, the most appropriate audit trails to follow would be:
A: Ask if customer complaints had ceased since the multi-skilled training finished. This audit trail is relevant because it directly relates to the effectiveness of the corrective action taken. If customer complaints have decreased or ceased, it could indicate that the additional training was effective1.
F: Review records to assess if all planned training has been completed. This trail is important to ensure that the training plan has been fully implemented and to verify that all staff members have received the necessary training. It also helps in assessing the adequacy of the training in terms of content, frequency, and outcomes1.
These two trails, A and F, are closely linked to the issue of customer complaints and the organization's response to them. They provide insight into whether the actions taken were suitable and whether they have led to improvements in staff performance and customer satisfaction1. The other options, while potentially useful, do not directly address the immediate concern of the effectiveness of the corrective actions taken in response to the customer complaints1.