Reliability theory is a branch of general probability, which has proved to be
of wide use in engineering sciences, since its introduction about 3 decades ago.
Reliability, is a logical framework within which indeterminacies inherent in engineering problems, may be analysed and solved quantatively by mathematical methods.
The present paper, gives an introduction to the fundamentals of relility, for
the engineers who are concerned with the word "Safety", practically. Although, the theory' is of the most general form, and may be applied to different statistical Systems, examples are given in the domain of civil Engineering. The wide range of problems. that civil engineering deals with, and its longer history in deterministic
outlooks, has made it more sluggish in adopting probabilistic concenpts , compared with other engineering practices.
Throughout out the paper, the author has tried to make a clear comparison between newly introduced concepts and more conventional ones, ie., the factors of safety.
In conclusion Practical problems are categorized as being appropriate for reliability analysis, or not so.
)