S oftware product lines (SPLs) undergo numerous changes to accommodate evolving needs of various market segments [1]. While some changes may apply to specific members, others permeate throughout the product line, often finding their way into the platform. In effectively managing evolution, product line development organizations are often faced with the following questions:• Are there general patterns of changes that are common in product lines? • If so, what change management practices can be used to effectively manage these patterns?We investigate these questions through a case study in a product line development organization (see the sidebar on how we conducted our study), identify three interesting patterns of change management, and suggest effective practices for addressing them.Establishing effective change management practices to prevent uncontrolled evolution of the product platform.