As most devices in a wide range of automotive, aerospace, and missile have built-in software that controls the system behaviors, the safety of the software is growing in its importance. That is, the software safety has emerged as one of big issues because the threat of accidents caused by software malfunction is rising. Accident by software can be occurred from user mal-operation, but the fundamental reason of the accident comes from insufficient verification of the safety in software development process. Therefore, this paper presents how the software safety analysis and management activities should be done in the development process. In particular, we propose how to apply the safety analysis and management activities in the prototype or incremental development process.