Does Hard Disk Drive Failure Rate Enter Steady-State Afer One Year?

This paper looks into the actual field return data of hard disk drive (HDD) and conducted an extensive study on the hazard rate, or failure rate, function and examined the time to reach steady state. It was found that the HDD hazard rate function doesn´t follow the traditional bathtub curve, but manifests itself as an increasing-decreasing-stabilized pattern. Furthermore, its time-to-steady-state is not one year as historically assumed by the industry. As it turns out, the generalized Gamma distribution is a better candidate to characterize the HDD non-traditional bathtub curve than Weibull and other non-Weibull parametric models. The corresponding reliability matrix, such as mean life, or mean-time-to-failure (MTTF), annual failure rate (AFR) during warranty, etc. are also derived. The findings and derived results in this paper will prove to have a constructive long-term impact on HDD industry in the understanding of HDD failure characterization, reliability quantification, risk assessment, and warranty prediction.