OneCycleAgeReplacementPolicy

class relife.OneCycleAgeReplacementPolicy(model, cf, cp, *, discounting_rate=0.0, ar=None, model_args=(), nb_assets=1, a0=None)

One-cyle age replacement policy.

The asset is disposed at a fixed age \(a_r\) with costs \(c_p\) or upon failure with costs \(c_f\) if earlier.

Parameters:

modelLifetimeModel

The lifetime model of the assets.

cfnp.ndarray

The cost of failure for each asset.

cpnp.ndarray

The cost of preventive replacements for each asset.

discounting_ratefloat, default is 0.

The discounting rate.

arnp.ndarray, optional

Times until preventive replacements. This parameter can be optimized with fit

model_argsModelArgs, optional

ModelArgs is a tuple of zero or more ndarray required by the underlying lifetime model of the process.

nb_assetsint, optional

Number of assets (default is 1).

a0ndarray, optional

Current ages of the assets (default is None). Setting a0 will add left truncations.

References

[1]

Coolen-Schrijner, P., & Coolen, F. P. A. (2006). On optimality criteria for age replacement. Proceedings of the Institution of Mechanical Engineers, Part O: Journal of Risk and Reliability, 220(1), 21-29

Methods

asymptotic_expected_equivalent_annual_cost	The asymptotic expected equivalent annual cost.
asymptotic_expected_total_cost	The asymptotic expected total cost.
expected_equivalent_annual_cost	The expected equivalent annual cost.
expected_total_cost	The expected total cost.
fit	Computes the optimal age of replacement for each asset.
sample	Sample simulation .

Attributes

discounting
model1
reward

asymptotic_expected_equivalent_annual_cost(dt=1.0)

The asymptotic expected equivalent annual cost.

Parameters:

dtfloat, default 1.0

The length of the first period before discounting

Returns:

ndarray

The asymptotic expected equivalent annual cost.

asymptotic_expected_total_cost()

The asymptotic expected total cost.

Returns:

ndarray

The asymptotic expected total cost for each asset.

expected_equivalent_annual_cost(timeline, dt=1.0)

The expected equivalent annual cost.

Parameters:

timelinendarray

Timeline of points where the function is evaluated

dtfloat, default 1.0

The length of the first period before discounting

Returns:

ndarray

The expected equivalent annual cost until each time point

expected_total_cost(timeline)

The expected total cost.

Parameters:

timelinendarray

Timeline of points where the function is evaluated

Returns:

ndarray

The expected total cost for each asset along the timeline

fit(inplace=False)

Computes the optimal age of replacement for each asset.

Parameters:

inplacebool, default is False

If True, it sets the optimal age of replacement inplace.

Returns:

OneCycleAgeReplacementPolicy (inplace is False) object or None (inplace is True)

sample(nb_samples, seed=None)

Sample simulation .

Parameters:

nb_samplesint

Number of samples generated

seedint, optional

Sample seed. Usefull to fix random generation and reproduce results

Returns:

RenewalRewardData

Iterable object that encapsulates results with additional functions