Safety analysis is an important part of developing safety critical software. There exists, however, little guidance on how the safety analysis shall be done as part of an agile safety lifecycle process. In the recent years, the development of safety critical systems has changed from mainly hardware related development to mainly software related development. It is therefore important to establish a sound process that includes the software engineers in the safety analysis process. Analysis First Development (AFD) could be seen as an approach similar to Test First Development (TFD). TFD refers to programming activities in which three activities are tightly connected: coding, testing (in the form of writing unit tests) and improvements (in the form of e.g. refactoring). Our suggested AFD approach includes safety analysis before the first sprint, during the first sprint (iteration), as a part of alongside engineering (performed by experts not part of the software sprint team, e.g. safety experts) and as part of change impact analysis. This paper describes how to use AFD as part of recommended techniques and practices by the safety standards when recertifying safety systems.