When "decision" of decision making and "selection" of proposition decision and "classification" of phenomenon etc. repeatedly it does at the multiple stages, ranking "the repetition of the divergence," graph expression, or that structural model which in the tree form figure (tree diagram) you draw and display.

Statistical decision theory,artificial intelligence, in fieldof machine learningand data mining etc., it is utilized in forecasting model construction, the solution of decision making analysis optimization and taxonomic problem, description of conceptual knowledge and extraction formation etc. of rule.

Regarding the field of decision making theory, being something which shows the multiplex decision problem model which repeats divergence with decision making and indefinite condition, process it shows the result which is estimated. It is the principal analysis tool of decision theory (decision analysis).