Procedures to monitor processes with low spoilage of Proportion.

Abstract

Production process of manufacture can be called as high-yield processes if spoilage proportion resulted is less than 100 parts per million (ppm). Control diagram p and np is less effective to show signal of out-of-control on the process of monitoring when the spoilage proportion is low. This paper describe cumulative control diagram of count control chart (CCC) based on geometric distribution (for CCC1) and negative binomial (for CCC2) lis more effective for monitoring low spoilage proportion. The results show that control diagram of CCC1 and CCC2 are more effective lebih efektif than p dan np. Controling implementation of damage number of oplah in PT Remaja Rosdakarya is p = 0,0002 and restored data is p = 0.0002 with 100 examined oplahs each day. Simulation data shows that there is a signal of ‘out-of-control on the 109th day for CCC1 and the 809th day for CCC2. This signal is false alarm. For controlling restored data with = 0.002, there is a signal of ‘out-of-control’ on the 22nd day for CCC1 and the 5th day for CCC2. And according to control diagram of np, the signal of appears in 14th day. So the control diagram of CCC2 provides true alarm period shorter than control diagram of np.