Method and apparatus for detecting abnormal characteristic values capable of suppressing detection of normal characteristic values

A method for detecting abnormal characteristic values of a plurality of products sequentially manufactured in the same manufacturing line, comprising:

• determining whether or not a successive upper tendency with respect to a control center value has occurred in a plurality of sequentially-obtained characteristic values of said products including a currently-obtained characteristic value;
• determining whether or not at least one of said characteristic values is located within a control region narrower than an allowable region and outside a normal region narrower than said control region;
• and
• detecting an alarm state when said successive upper tendency has occurred and said at least one characteristic value is located within said control region outside said normal region.

An apparatus for detecting abnormal characteristic values of a plurality of products sequentially manufactured in the same manufacturing line, comprising:

• a successive lower tendency determining section for determining whether or not a successive lower tendency has occurred in a plurality of sequentially-obtained characteristic values of said products;
• and
• a normal region determining section for determining whether or not at least one of said characteristic values is located within a control region narrower than an allowable region and outside a normal region narrower than said control region,
• thus detecting an alarm state when said successive lower tendency has occurred and said at least one characteristic value is located within said control region outside said normal region.

An apparatus for detecting abnormal characteristic values of a plurality of products sequentially manufactured in the same manufacturing line, comprising:

• a successive upper tendency determining section for determining whether or not a successive upper tendency has occurred in a plurality of sequentially-obtained characteristic values of said products;
• and
• a normal region determining section for determining whether or not at least one of said characteristic values is located within a control region narrower than an allowable region and outside a normal region narrower than said control region,
• thus detecting an alarm state when said successive upper tendency has occurred and said at least characteristic value is located within said control region outside said normal region.