A circle chart for periodic measurements

Periodic measurements are very common in practice, with a specific characteristic, periodicity. In this paper, we propose a type of control chart that plots the measurement around a circle. By doing so, information from the same stage of different cycles can be compared easily. Some basic properties are investigated and further developments are discussed. The basic circle chart can also be applied under various kinds of control chart schemes. Furthermore, the circle chart has good chart performance and potential for further development. Application examples are also shown in this paper.