The goal of this report is to describe the state-of-the-art of embedded software maintenance and provide a glimpse of state-of-the-practice embedded maintenance practices. Section 2 introduces the area of embedded software based on embedded systems, the implication of embedded software and some of its characteristics. Section 3 describes the more general area of software maintenance, different process models and characteristics. Section 4 analyzes embedded software maintenance and investigates how the characteristics of embedded systems affect software maintenance and then describes the typical problems and issues in maintenance. This section also links typical problems to the case studies that can be found in Appendix A. Section 5 discusses potential solutions. One solution, impact analysis, addresses problems that are identified in many case studies; we discuss impact analysis in Section 6.