A binary tree structure for detecting inventory problems. A first embodiment
on-hand inventory problems. A second embodiment detects inventory requirements
problems. Both embodiments use a binary tree whose nodes store time values and
delta values. (FIG. 2). The delta values represent inventory consumers or producers.
(FIG. 6). The time values of trees used for inventory requirements problems are
shifted in accordance with build-ahead times. (FIG. 6).