The increasing complexity of modern software-intensive systems makes their analysis much more difficult. At the same time, more and more of these systems are used in safety-critical environment. Model based safety analysis can help with this problem by giving provably correct and complete results, very often in a fully automatic way. Today, such methods can cope with logical as well as probabilistic questions. However, very often the models used in many model based approaches must be specified in different input languages depending on the chosen verification tool for the desired aspect, which is time consuming and often error-prone. In this paper, we report on our experiences in designing a tool independent specification language (SAML) for model based safety analysis. This allows to use only one model and analyze it with different methods and different verification engines, while guaranteeing the equivalence of the analyzed models. In particular, we discuss challenges and possible solutions to integrate SAML in the development process of real systems.