A new method of hard disk drive MTTF projection using data from an early life test

Traditionally, the exponential and the Weibull distribution approaches have been mainly used in the hard disk drive (HDD) industry to evaluate mean time to failure (MTTF) from a life test in which only early failures may be observed. This paper proposes an approach for projecting disk drive field MTTF using a two-phase bathtub curve failure rate function. Based on this 2-phase bathtub curve failure rate function, the MTTF expression is derived and turns out to be a weighted sum of the mean lives of the early failure and useful life distributions. Numerical simulations indicate that the proposed method is superior than the traditional ones.