An engineering procedure used in complex multistage decision-making problems that involves planning and organizing decisions. It takes into account how choices are made at earlier stages, the outcomes of possible external events that determine the types of decisions, and events at later stages of that sequence. The decision-making tree represents, in an organized way, the decisions and events that introduce uncertainty, as well as possible outcomes of all those decisions and events. The (p. 99) nomenclature involves squares that represent decisions. Lines from squares represent options that can be selected. Circles show various circumstances that have uncertain outcomes. Lines from circles denote possible outcomes of that uncontrollable circumstance.