The ability to handle changes is a characteristic feature of successful software projects. The problem addressed in this paper is what should be done in project planning and iterative replanning so that the project can react effectively to changes. Thus thework presents research results in software engineering, as well as transfer of methodsin knowledge engineering to software engineering, applying the AI planning techniqueto softwareprocess modelingand softwareproject management. Our method is based on inter-project experience and evolution patterns. We propose a new classification of software projects, identifying and characterizing ten software process evolution patterns and link them to different project profile. Based on the evolution patterns, we discuss the planning support for process evolution and propose several methods that are new or significantlyextend existing work, e.g. cost estimation of process changes, evolution pattern analysis, and a coarse process model for the in...