Editing Failure rate (section)

===Coefficient of variation===

When the failure rate is decreasing the [[coefficient of variation]] is ⩾&nbsp;1, and when the failure rate is increasing the coefficient of variation is ⩽&nbsp;1.{{clarify|date=December 2024}}<ref>{{Cite journal | last1 = Wierman | first1 = A. | author-link1 = Adam Wierman| last2 = Bansal | first2 = N. | last3 = Harchol-Balter | first3 = M.|author3-link=Mor Harchol-Balter | title = A note on comparing response times in the M/GI/1/FB and M/GI/1/PS queues | doi = 10.1016/S0167-6377(03)00061-0 | journal = Operations Research Letters | volume = 32 | pages = 73–76 | url = http://users.cms.caltech.edu/~adamw/papers/fbnote.pdf| year = 2004 }}</ref> Note that this result only holds when the failure rate is defined for all t&nbsp;⩾&nbsp;0<ref>{{cite book | title = Analysis of Queues: Methods and Applications | first = Natarajan | last =Gautam | publisher = CRC Press | year = 2012 | page = 703 | isbn = 978-1439806586}}</ref> and that the converse result (coefficient of variation determining nature of failure rate) does not hold.