Statistical Process Control based on state space model

It is difficult to apply traditional Statistical Process Control (SPC) technology as state variables are unmeasurable in small batch production process. A modified individual control chart based on state space model was proposed in this paper. The process state was estimated through particle filter technology. The median of state particles group was monitored by Average Moving Range (AMR) control chart to detect variation of normal distribution process. Results showed that the proposed chart was an effective tool to monitor small batch production process.