The safety life cycle is the series of phases from initiation and specifications of safety requirements, covering design and development of safety features in a safety-critical system, and ending in decommissioning of that system. This article uses software as the context but the safety life cycle applies to other areas such as construction of buildings, for example. In software development, a process is used (software life cycle) and this process consists of a few phases, typically covering initiation, analysis, design, programming, testing and implementation. The focus is to build the software. Some software have safety concerns while others do not. For example, a Leave Application System does not have safety requirements. But we are concerned about safety if a software that is used to control the components in a plane fails. So for the latter, the question is how safety, being so important, should be managed within the software life cycle.[1]