Weibull Analysis and Zero-time Failures. What Are Your Data Analysis Options?

This paper discusses the issues of processing life data containing zero-time failures, which are often the result of out-of-box, assembly line, screen test or other types of failure that occur before a product begins its field operation. Processing these zero-time failures can be a challenging task, since most statistical distributions and analysis software packages do not handle zero time values well. Therefore it is important for the analyst to have a good understanding of the data, including failure modes, data sources, mode of fault detection, and the product's design and manufacturing process. This paper discusses real life situations with zero-time failures and suggests different approaches to handling such data. Examples and case studies are provided for each analysis method.