Altarica is a modeling language for safety analysis and supports simulation analysis. Although Altarica is widely used in the industry, research studies on simulation algorithm are rarely found. Therefore, we design and implement a simulation algorithm. We first briefly introduce the syntax and characteristics of Altarica, and then describe the design and implementation of the algorithm in detail, and finally accurately simulate the most probable sequence of events. We use Reverse Polish Notation to deal with complex event triggered conditions, and support three kinds of synchronization, including Synchronization, Broadcasting and Common Cause Failure, and support multiple probability distribution types. At the end of this paper, through case study and comparison with SIMFIA, the correctness of the algorithm is proved.

Dependability analysis is the main method to evaluate the design of safety-critical systems, which is able to analyze the source of the faults and find them as early as possible. With the increasing system scale and complexity, Model-Based Dependability Analysis (MDBA) has become the mainstream, so that it is crucial to provide powerful models that accurately reflect the real systems and easy to be built. However, modeling a system is error-prone and it is difficult to verify the correctness of the model being built. Therefore, this paper proposes our dependability modeling tool called DATAM (Dependability Analysis Tool of AltaRica Model), which is based on AltaRica, a dataFlow language. We present a method for converting key elements of AltaRica into model/GUI components, thereby ensuring the consistency of the model with the modeling language. GUI-based operations and rich custom components ensure ease of using DATAM. Besides, some components of the model can be edited directly through the AltaRica script and can be interchanged with GUI components. Finally, DATAM supplies varieties of reliability calculation functions. We demonstrate the ability of DATAM through a case study and compare the results with SimFia education version.

Since the AltaRica language has, in fact, become the European industry standard, the AltaRica-based simulation method is one of the important research contents in the field of safety analysis methods. At the same time, in practical applications, simulations are mostly executed tens of thousands of times. Therefore, it is practical to optimize the execution time of the simulation method. We first analyze the hotspots in the execution of simulation methods and then propose two optimization strategies for two hot issues. The optimization method is designed and implemented by the method of space for time. Finally, the effectiveness and application scenarios of the optimization method are illustrated by experiments with different scale models.Moreover, the experiment data shows that the optimization method is effective in most cases.