Formal transformation methods for automated fault tree generation from UML diagrams

With a growing complexity in safety critical systems, engaging Systems Engineering with System Safety Engineering as early as possible in the system life cycle becomes ever more important to ensure system safety during system development. Assessing the safety and reliability of system architectural design at the early stage of the system life cycle can bring value to system design by identifying safety issues earlier and maintaining safety traceability throughout the design phase. However, this is not a trivial task and can require upfront investment. Automated transformation from system architecture models to system safety and reliability models offers a potential solution. However, existing methods lack of formal basis. This can potentially lead to unreliable results. Without a formal basis, Fault Tree Analysis of a system, for example, even if performed concurrently with system design may not ensure all safety critical aspects of the design. [Continues.]</div

Principles of logic design

This study involves logic design and switching theory, in particular their practical application to the logic design and understanding of digital machines. Digital machines, of course, play an extremely important role in that large class of machines known as digital computers. But they also play an important role in many other kinds of practical devices important in the design of communications systems, digital control systems, counters, registers, digital meters, and so on. The basic content of switching theory is very simple. It embodies that body of machines and machine behavior that can be realized with "switches", things that are either "on" or "off", and nothing, really, could be much simpler than that. Of course the world is really comprised of very many complex structures which are really composed of exceedingly simple lesser structures, so that we really shouldn't be too surprised that even though the elements of switching theory are quite simple, their consequences are not necessarily so. The goals of our study are several, and include at least the following: 1) to develop some understanding and capability in using the techniques, design procedures, and models that have been developed for understanding and designing digital networks; 2) to explore in some modest detail the kinds of questions with which logic designers and practitioners concern themselves; 3) to develop an appreciation for the tremendous variation possible in digital design requirements and specifications, i. e,, for the complexity of the 'finite' digital problem, and hence an understanding of the need for systematic design techniques by which to attack such problems; 4) to gain some practice with the fundamental tools and techniques of logic design I so that the reader can adapt the techniques to the "new" problem presented by his own particular design constraints; and 5) to provide an introduction to the literature so that the discerning student can, in the future, dip into the ever growing literature in the field, and find it to some degree comprehensible, and advantageous to use