A general model of the management science implementationprocess is presented based on the results of more than ten yearsof implementation research. A multiple-equation representationof that model is developed for one important class of implementation,the two-stage implementation, in which it is necessaryto gain both user and management acceptance of the system beingimplemented. The postulated model represents an advance in atleast three ways: (a) it integrates previous findings; (b) itgeneralizes across settings; and (c) it is testable as a whole