Embedded software is a sub-system that needs to be integrated with the electrical and mechanical subsystems for a functional medical device to be developed and marketed. In order to be able to develop a medical device system through integrating its sub-systems, the complete system requirements should be known at the start of the project and managed throughout development. Software requirements are then derived from the systems requirements. We have developed and piloted a medical device software process assessment framework called MDevSPICE® that integrates processes from various medical device software standards as well as generic software development standards. This paper describes how the MDevSPICE® framework has been designed so as to enable medical device software developers to produce software that will be safe and easily integrated with other sub-systems of the overall medical device. We also describe the lessons learned from piloting MDevSPICE® in the medical device industry and challenges medical device software developers meet in tracing requirements and risks to and from the system level.