Functional hazard analysis advantages

Software System Hazard Analysis This type of analysis is conducted similar to a hardware system hazard analysis (SHA), analyzing software functional processing steps to determine whether they may have any particular hazardous effect on the system. The analysis utilizes a hazard-risk index to illustrate the severity of each potential failure. The main advantage to this method is in its ability to positively identify safety-critical hardware and software functions as well as consider the effect of the human element in system software operations. The results of the software SHA, which identifies single-point failures or errors within a system, can often be used to assist in the development of a software fault tree analysis or, to some degree, a system FMEA. However, as with the other various SWHA techniques briefly described above, this method is also time-consuming and costly to perform. 

Another well-known technique of hazard identification is the HAZOP (HAZard and OPerability) method. With this method, hazards are identified and analyzed using sessions with operational experts. At the same time, the experts come up with potential solutions and measures to cope with the identified hazards (Kletz, 1999). The advantage of HAZOP with respect to the functional approach is that also nonfunctional hazards are identified during the brainstorm with operational experts. However, in applying HAZOP, one needs to take care that hazard analysis and solution activities do not disturb the hazard identification process, which could leave certain hazards unidentified or inappropriately solved . Leaving such latent hazards in a design typically is known to be very costly in safety critical operation. 

Among the advantages of the FHA technique are that it is easily and quickly performed, it provides rigor for focusing on hazards associated with system functions, it is a valuable tool for SwS analysis, and it helps to identify SCFs in the system. Since the technique focuses on functions, it might overlook other types of hazards, such as those dealing with hazardous energy sources or sneak circuit paths. This is why other analysis tools are also required. 

In many Raman spectrometers, the use of hbre optics and waveguides can produce a big advantage. Samples that cannot be introduced into the Raman spectrometer due to their size or hazardous nature can be investigated in situ. A lens is fixed on the end of the fibre optic probe to focus the laser beam and to function as the collecting windows in backscattering geometry. The fibre is pointed at the sample and Raman spectrum is acquired. Small sample spots (about 1 pm) can be analysed this way (Smith and Dent 2005). Moreover, the portable Raman spectrometers can be used for rapid and in sim Raman analysis, which wiU be demonstrated in Chap. 4. 

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