The Hazard and Operability (HAZOP) study is the most commonly used process hazard analysis (PHA) method in the process industries. While the HAZOP method provides a more thorough and complete treatment than other classical PHA methods, HAZOP studies tend to be tedious and time-consuming which can compromise the quality of the work performed. Major Hazard Analysis (MHA) was developed in an attem...

The study of serious accidents, which have occurred in the chemical process industry in recent times, highlights the need to understand fluid property related phenomena and the interactions between chemicals under abnormal process conditions or with abnormal fluid compositions. Consideration of these issues should be common practice in professional safety analysis work, and computer programs de...

Concerned with serious problems regarding security as a safety issue, a HAZOP specifically suited for identifying security threats has been developed. Unfortunately, the emphasis placed on security issues when developing safety critical systems is to often inadequate, possibly due to the lack of ”safety-compliant” security methods. Having had the opportunity to adapt the HAZOP-principle to the ...

This paper reports on an experiment comparing three reading techniques: ad hoc, UML-HAZOP and scenario-based applied during inspection of UML models. UML-HAZOP is a reading technique adopted from the domain of safety analysis of critical systems. The technique and its variants applied in experiment are outlined in the paper. Design, a way of conducting and results processing of the experiment a...

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 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 ...

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...