Research On Small Batch Procedure Quality Control Method And Their Key Techniques

With the increasing need of diversification and individuation, more and more enterprises turn their steps to multi-kind and small batch production. SPC technology is not suitable for small batch procedure quality control because of few samples. Most enterprises adopt "100% inspection" method which cannot realize the prediction of procedure quality. Therefore, Small Batch procedure quality control system based on virtual procedure is constructed to assist managers in analyzing various procedure quality.Similarity theory is adopted in analyzing a great deal of similar procedure existence and quality eigenvalue factors are ascertained based on it when similarity is 1. Structure layers and functions of procedure analytical factors are determined and coding system is constructed of quality eigenvalue factor which definitudes the condition of quality eigenvalue groups. Thus the batch is enlarged and the problem of few samples is solved.The concept of "Virtual Procedure" is proposed and "Virtual Procedure" is used to represent original procedures with the same coding. Running Chart and EWMA Chart are combined to realize the prediction of original procedure quality and virtual procedure quality statistical control. Different "virtual procedures" are constructed for known standard value value and unknown standard value value and data mapping method and procedure status judgement regulations are proposed.Standard value value validate chart and real time control chart are applied to standard value value-known and standard value value-unknown situations separately when the batch of sample is not enough to be analyzed. The two methods are stated in details on working principles, application theorem and characters, etc.Framework, developing software, main modules functions of the system and its key techniques are stated. The system can create unique code of procedure quality eigenvalue varying rule and can group such procedures with the same code. The system can automatically judge the abnormity of running chart, EWMA chart, standart validate chart and real time control chart. The sharing with derivable CAPP is discussed in theory.Application instances prove the reliability and practicability of the system.