Reliability prediction in early phases of product design

Computer support of design and development procedures is becoming more and more diversified, sophisticated and efficient. Can it be expected that the design and development process will, in the future, be fully controlled by highly sophisticated computer support, analytical modeling and simulation? The paper explains some drawbacks of the design evaluation method by which dimensional suitability is evaluated using the criterion or 'sufficient safety', and points to the advantages of 'design for reliability' enabling simultaneous evaluation of the functional and dimensional suitability of solutions. Research has shown that even the most complete computer-supported analytical methods do not enable the designer to predict reliability during operation with sufficiently low statistical risk. Even the implementation of partial, yet relevant tests results into the analytical reliability evaluation process does not essentially improve its efficiency. It is only model or prototype testing that makes it possible to predict reliability with sufficiently low risk. A new method was developed to predict the probability of stress state occurrences during operation. It probably need not be mentioned that this kind of reliability prediction requires maximum computer support. So to meet these needs, a computer-supported system for this kind of analysis has been developed.