ABSTRACT
Calculations using the Weibull and lognormal distributions are usually associated with a more deterministic approach. Reliability calculations using the Weibull and lognormal distributions are quite complicated. Deterministic reliability is more a management approach than a set of methods. Constant failure rates are coupled with a probabilistic approach to reliability. Deterministic reliability, on the other hand, usually includes the assumption that the failure rates are not constant. All operating and storage conditions which may impact reliability must be known and communicated to the product designer and manufacturer. To be useful in designing for reliability, the ambient and operating conditions must be known in terms of specific temperatures, humidities, vibration limits, voltages. Quality and reliability do not end when a material or component is selected and the supplier is chosen. Some progressive manufacturers require the quality and reliability of all new manufacturing processes and materials to be verified by a properly designed experiment prior to implementation.
