Safety critical systems are growing more complex. To keep these systems safe, methods and techniques are necessary to prevent accidents from happening. Earlier when the engineered systems were smaller and the possibility for large scale destruction was not there, we had the luxury of being in a position to learn from experience. Due to the catastrophes safety critical systems can cause today, w...

In recent years, serious accidents in chemical plants frequently occurred in Japan. In order to prevent accidents and to mitigate process risks, to re-evaluate risks which consider the reliability of existed safeguards in chemical plants is needed. The chemical plant is obligated to provide and maintain a safe environment for people that live in such circumstances. Plant safety is provided thro...

In this paper, we present the use of D-higraphs to perform HAZOP studies. D-higraphs is a formalism that includes in a single model the functional as well as the structural (ontological) components of any given system. A tool to perform a semi-automatic guided HAZOP study on a process plant is presented. The diagnostic system uses an expert system to predict the behavior modeled using D-higraph...

There is a clear link between safety and reliability in system design and operation. So the knowledge about sources of failure, their physical consequence related to plant operation and the frequency of effects (incident consequence) is of great value for improvement. Next, the selection of best improvement alternative should be justified by complete life cycle cost benefits. In this contributi...

Hazard and Operability (HazOp) and Fault Tree Analyses (FTA) are embedded into UML component models. The latter are constructed by employing UML's extension mechanisms in conjunction with component-based software techniques. Taking an application's safety-related requirements into consideration, the elements of HazOp and FTA are defined as component attributes, and assigned to a UML component m...

The progress of artificial intelligence techniques, particularly decisional mechanisms, has allowed reactive systems to become more autonomous. This allows new applications in domains such as service robotics in which failures can lead to human injury or death, or financial loss. To ensure safety of such systems, we propose in this paper a process, based on a HAZOP/UML risk analysis, to elicit ...

INTRODUCTION The accidents at Texas City and Buncefield remind us of the importance of human factors in preventing major accident hazards in the Process Industry. Much of the advice focuses on organisational factors required to ensure a motivated and competent workforce working within a good safety culture. Another key area that is often overlooked is the design of plants, processes and procedu...

A widely used hazard identification technique within the process industry is HAZOP (hazard and operability study). To overcome the repetitive and time-consuming nature of the technique automated systems are being developed. This work considers batch processes, in which material undergoes processing in distinct stages within the plant equipment items according to a set of operating procedures, r...

Some results of the implementation of a new support tool for automated hazard analysis are presented in this paper. We describe in detail the further progresses on the application of intelligent systems to the hazard analysis and especially to the HAZOP and FMEA analysis. A previously developed program, that allows the automatic generation of the report of the HAZOP analysis as regards the dete...

Safety-critical systems which are systems that may harm the environment they are operating in are commonplace. Standards and regulations for developing software for safety-critical systems usually require restricted programming languages and formal methods. For reasons of scale and for coping with the complexities of large systems it may be beneficial to use modern object-oriented techniques in...