Models and Managers: The Concept of a Decision Calculus

A manier tries to put together the various lesouroes under hu eontrol iato AH aotivitjr that aehieves his objectives. A model of his operation ean astdst him but isrobably will not unless it meets oertun requirements. A model that k to be used by a manager should be simple, robust, easy to control, adaptive, as comidete as poonUe, and easy to communicate with. By simile is meant eaqy to understand; by itdnut, hard to get absurd answers from; by easy to eontrol, that the user knows wbait input data would be required to produi» desired output answera; adaptive means that the model can be adjusted as new information is acquired; ctunideteneas imidies tiiat important i^nomena will be included even if they requira judipamttal estimates of their effect; and, finally, esmy to communicate w i ^ means tiiat ^ num^ier e»n quickly and easily change inputs and obtun and understand tiie outputs. Such a modd conobts of a set of numerical procedures for jnocessing data and judgments to assist miuiagerial deckion making and so will be called a deckdon otlcdus. An examide from marketing is described. It is an on-line moM for me by psodaet nanageis on advertitnng budgeting questions. The model is currently in tiM mm by several product mani^ers.