Algorithm of Multi-Causes Process Quality Diagnosis Using Binary Tree and Intermediate Quality

Process quality control is the core in product’s quality management. To solve the problem of multi-causes process quality diagnosis in manufacturing, an algorithm based on binary tree of quality cause set and intermediate quality is proposed. Firstly, the set of quality cause is divided progressively to form a complete binary tree, and then every node of subsets is chose as non-control cause set to construct the cause-selecting control chart of the intermediate qualities in its parent node. In diagnosis, control charts with same parent are compared to narrow the scope of abnormal quality causes until they are confirmed. Practice proves that the proposed algorithm can make the procedure of quality cause judgment independent to the adjustment, thus the comparison times of control charts could be greatly reduced and the efficiency of diagnosis is highly promoted.