A plant drawing line detection system acquires a plant drawing that is used for construction, operation, and maintenance of a plant, displays the acquired plant drawing, accepts selection of a line that is desired from among a plurality of lines that are present in the displayed plant drawing, registers a line pattern of the accepted selection of the line, detects, from the displayed plant drawing, all of the lines each having a shape that is matched with a shape of the registered line pattern including the line that has been used for the selection, and provides a detection result related to the lines.

A plant drawing symbol detection system acquires a plant drawing that is used for construction, operation, and maintenance of a plant, displays the acquired plant drawing, accepts selection of a symbol that is desired from among a plurality of symbols that are present in the displayed plant drawing, registers a symbol pattern of the accepted selection of the symbol, detects, from the displayed plant drawing, all of the symbols each having a shape that is matched with a shape of the registered symbol pattern including the symbol that has been used for the selection, and provides a detection result related to the symbols.