Assessing uncertain ventures using experts' judgments in the form of subjective probabilities

The paper deals with a procedure known as ASPRO which has been successfull applied at Shell Oil Company. Section II addresses general problems encountered in using subjective assessment procedures. Section III introduces ASPRO's decomposition process which is designed to alleviate some of the problems. The decomposition process produces a questionnaire, the answers to which are the inputs to the ASPRO assessment procedure. Examples of the questionnaire for assessing political risks to oil investment ventures and analyzing new product sectors are given. Section IV explains how the respondents assess the component parts, and Section V outlines the mechanical procedures which are used to combine the assessments. Examples of how ASPRO's output can be used to communicate the respondents' quantified judgments are given in Section VI. Conclusions are in Section VII.