如何进行客户满意度的调查

事实上ISO9001标准并不告诉你如何进行，谁做。让我们再看一下标准是如何描述的：
8.2.1 Customer Satisfaction
As one of the measurements of the performance of the quality management system, the organization shall monitor information relating to customer perception as to whether the organization has met customer requirements. The methods for obtaining and using this information shall be determined.

Note: Monitoring customer perception can include obtaining input from sources such as customer satisfaction surveys, customer data on delivered product quality,user opinion surveys, lost business analysis, compliments, warranty claims and dealer reports.

此标准说明了组织应监控关系到客户对组织是否满足客户要求感知方面的信息。具体的获取和利用信息的方法没有界定。
在备注中，列举了一些监控客户感知的一些手段。但没有说要一定使用调查问卷（Questionnaires).
所以在此想要获得一些信息，各位是如何具体操作的，哪一种实践是最佳的？