▁uncertainty ▁is ▁high , ▁while ▁small ▁devi ations ▁from ▁the ▁estimate ▁are ▁possible ▁even ▁when ▁the ▁uncertainty ▁is ▁small . ▁ ▁These ▁en velop es ▁are ▁called ▁info - g ap ▁models ▁of ▁uncertainty , ▁since ▁they ▁describe ▁one ' s ▁understanding ▁of ▁the ▁uncertainty ▁surrounding ▁the ▁re venue ▁functions . ▁ ▁From ▁the ▁info - g ap ▁models ▁( or ▁uncertainty ▁en velop es ) ▁of ▁the ▁re venue ▁functions , ▁we ▁can ▁determine ▁an ▁info - g ap ▁model ▁for ▁the ▁total ▁amount ▁of ▁reven ues . ▁Figure ▁ 5 ▁illustr ates ▁two ▁of ▁the ▁uncertainty ▁en velop es ▁defined ▁by ▁the ▁info - g ap ▁model ▁of ▁the ▁total ▁amount ▁of ▁reven ues . ▁ ▁Rob ust ness ▁High ▁reven ues ▁would ▁typically ▁ear n ▁a ▁project ▁manager ▁the ▁senior ▁management ' s ▁respect , ▁but ▁if ▁the ▁total ▁reven ues ▁are ▁below ▁a ▁certain ▁threshold , ▁it ▁will ▁cost ▁said ▁project ▁manager ' s ▁job . ▁We ▁will ▁define ▁such ▁a ▁threshold ▁as ▁a ▁critical ▁re venue , ▁since ▁total ▁reven ues ▁beneath ▁the ▁critical ▁re venue ▁will ▁be ▁considered ▁as ▁failure . ▁ ▁For ▁any ▁given ▁allocation , ▁the ▁robust ness ▁of ▁the ▁allocation , ▁with ▁respect ▁to ▁the ▁critical ▁re venue , ▁is ▁the ▁maximal ▁uncertainty ▁that ▁will ▁still ▁guarantee ▁that ▁the ▁total ▁re venue ▁will ▁exceed ▁the ▁critical ▁re venue . ▁This ▁is ▁demonstrated ▁in ▁Figure ▁ 6 . ▁If ▁the ▁uncertainty ▁will ▁increase , ▁the ▁en velope ▁of ▁uncertainty ▁will ▁become ▁more ▁inclus ive ,