A Method for Determining Safety Requirements  
Author Shiyu Gong


Co-Author(s) Bohua Li; Pengcheng Luo


Abstract Determining of the safety requirements is a prerequisite for ensuring system safety. STAMP (System-Theoretic Accident Model and Processes), created by Dr. Nancy Leveson and utilized to consider the safety as a hierarchical control problem, has offered a new approach to solving safety problem. The most basic concept in STAMP is a safety constraint. But, how to determine the safety constraints or safety requirements is still a difficult problem, and is in urgent need of the further investigation. The paper suggests a method for determining the safety requirements by means of the hierarchical control principle in STAMP. In the method, the engineering safety design process is abstracted and focused on the safety analysis and design between the parent node and its sub-nodes on the adjacent levels of the system hierarchy. The sub-node’s behavior is examined and contrasted with the current safety requirements on the node and its parent. Then, the risks of any violations of the safety requirements could be assessed. Dependent on the results of risk assessment, the iterative safety design and new safety requirements identification could be proceeded. The proposed method is demonstrated with an example on spacecraft re-entry capsule.


Keywords safety requirements; requirement analysis; STAMP; Hierarchical Control; safety design
    Article #:  21287
Proceedings of the 21st ISSAT International Conference on Reliability and Quality in Design
August 6-8, 2015 - Philadelphia, Pennsylvia, U.S.A.