A software process innovation, such as software reuse, involves both technology and administration innovation. Following literature on organizational change, absorptive capacity, innovation assimilation stages, and software reuse, we develop a process model of the assimilation trajectory of an organization's innovation. The model postulates that actors at different organizational levels implement strategy, process, and culture changes in order for an organization to advance through the stages of innovation assimilation. The actions at these levels instill routines that establish the absorptive capacity for implementing future innovations. Case-study data collected from four software development sites -two reporting failure in the reuse program, and two reporting success -revealed that programs that implemented change at the strategy, process and culture levels scored higher on all paths in the model than nonsuccessful programs. The right incentives help in the latter stages of innovation assimilation during which culture change by operational staff is important. No reuse metrics were collected Team-based structures Frequent formal and informal communication Infrequent formal communication Infrequent formal communication Frequent formal and informal communication