There are various factors affecting quality of the statistical survey in different stages. Recognizing these factors trying to upgrade or keeping power points while removing the problems and weak points shall lead quality improvement in statistical survey. We can recognize these issues in different stages by using various methods. Even, if recognition of power and weak points in different parts of the statistical survey seems to be very important, but they are inadequate. Analyzing recognized issues and using statistical method are necessary for continuous quality improvement. We can point out different elements in this field such as Pareto Chart and Cause and Effect Diagram.

In this Article, while introducing these methods, their application is also examined in quality control of statistical survey.