# IEC 61703:2001 pdf download

IEC 61703:2001 pdf download.Mathematical expressions for reliability,

availability, maintainability and maintenance support terms.

Mean time to failure

Point estimate of the mean time to failure

Mean time to restoration

Point estimate of the mean time to restoration

Mean undetected fault time, i.e. the expectation of the undetected fault time

Mean up time

Point estimate of the mean up time

Asymptotic unavailability

Instantaneous unavailability (unavailability function)

Mean unavailbility for the time interval (h, 12)

Point estimate of the mean unavailability for the time interval (1, 12)

Expected number of failures in the time interval Z(0) = E[N(0)], where E denotes the expectation

Probability density function of the (operating) times to failure

Probability density function of the up times

Probility density function of the sum of the up times and the corresponding times to restoration

Probability density function of the active corrective maintenance times

Probability density function of the administrative delays

Probability density function of the active maintenance times

Probability density function of the down times

Probability density function of the logistic delays

Probability density function of the times to restoration

Probability density function of the repair times

Probability density function of calendar time to the nth failure, n2 1

Number of active corrective maintenance actions during a given period of observation

Number of administrative delays during a given period of observation

Number of down times during a given period of observation

Number of filures during a given period of observation

Number of logistic delays during a given period of observation

Number of failures while operating during a given period of observation

Number of times to restoration during a given period of observation

Number of repair times during a given period of observation

Number of up times during a given period of observation

Number of items in the population

Number of items that are in a down state at the instant of time

Number of failures observed during the time interval (, 1 + An), where the time scale includes both up and down times

Number of failures observed during the time interval (t, ta2), where the time scale includes both up and down times

Number of items that were operational at the instant of time 1 and operated without filure in the time interval (I, t2)

Number of items that are in an up state at the instant of time 1

Instantaneous restoration intensity

Instantaneous failure intensity

Asymptotic failure intensity

Point estimate of the instantaneous failure intensity at time

Mean failure intensity for the time interval (1. a)

Point estimate of the mean failure intensity for the time interval (1, 12)

Constant failure rate, i.e. the reciprocal of mean time to failure (MTTF) when time to fallure is exponentially distributed

Constant rate of transition from an up state to a down state, i.e. the reciprocal of the mean up time (MUT) when up times are exponentially distributed

Constant repair rate, i.e. the reciprocal of the mean corrective maintenance time (MCMT) when the corrective maintenance times are exponentially distributed

Instantaneous repair rate

Mean repair rate for the time interval (M, 12)

Reciprocal of the mean active corrective maintenance time (MACMT) when the active corrective maintenance times are exponentially distributed

Reciprocal of the mean administrative delay (MAD) when the administrative delays are exponentally distributed

Reciprocal of the mean active maintenance time (MAMT) when the active maintenance times are exponentially distributed

Reciprocal of the mean down time (MDT) when the down times are exponentially distributed

Reciprocal of the mean logistic delay (MLD) when the logistic delays are exponentially distributed

Constant rate at which the item is restored to service (constant resto- ration rate), i.e. the reciprocal of the mean time to restoration (MTTR) when the times to restoration are exponentially distributed Reciprocal of the mean repair time (MRT) when the repair times are exponentially distributed.