TechGuide ~ PartModules ~ Reliability

Reliability

The part has the capability of module failure. This module disables other modules when a failure happens.

PROPERTY	DESCRIPTION	DEFAULT
type	name of the component part module (f.i. ModuleParachute)
mtbf	mean time between failures, in seconds. set to 0 to disable mtbf failures.	21600000.0
repair	trait and experience required for repair, in the form trait@experience
title	short description of component
redundancy	redundancy group
extra_cost	extra cost for high-quality, in proportion of part cost	0.0
extra_mass	extra mass for high-quality, in proportion of part mass	0.0
rated_radiation	works in combination with MTBF only: the amount of radiation (in rad/h) this part can endure without taking additional damage. if set to 0 there will be no radiation damage.	0.0
radiation_decay_rate	works in combination with MTBF only: the rate at which the time to next failure is reduced while in radiation	20

Engine failures

PROPERTY	DESCRIPTION	DEFAULT
turnon_failure_probability	probability of a failure upon ignition (0..1)	0
rated_operation_duration	burn duration that can be expected from an engine with a reasonably low probability of breakdown (seconds)	0
rated_ignitions	ignitions this engine is expected to sustain. warranty void if exceeded.	0

turnon_failure_probability, rated_operation_duration and rated_ignitions work for engines only, specifically for ModuleEngines and ModuleEnginesFX. If the value is 0, the feature is disabled (f.i. there will be no ignition failures if rated_ignitions is 0).

Every time an engine is ignited (that is when it provides thrust when it didn't before, not when the engine part module is turned on in the part action window), there is a chance of turnon_failure_probability that the engine will experience a failure on ignition. Engine might explode on failure (p = 10%).

Engines get 35% of the rated_operation_duration guaranteed without failure, after that the failure rate rises exponentially. Engine might explode on failure (p = 35%).

rated_ignitions are guaranteed engine relights without failure. Any additional ignitions come with increasing odds of failure. Engine might explode on failure (p = 10%).

MTBF

Althought MTBF is mean time between failures, the implementation guarantees 50% of the MTBF without failures. We found MTBF based failures too frustrating without that guarantee. After that the failure rate raises exponentially, and pretty much guarantees a failure after 150% of the MTBF.

Radiation Damage

While the vessel experiences radiation that exceeds the rated_radiation level, the MTBF is effectively reduced at a rate that depends on radiation_decay_rate and the amount that the current level of radiation exceeds the rated radiation level.

Description

Parts with the reliability module can optionally be set to high quality in the editor:

• High quality parts will have the extra_coss added to the part cost
• High quality parts will have the extra_mass added to the part mass
• MTBF will be multiplied by the quality scale value (configured in Settings, QualityScale, default is 4)
• turnon_failure_probability will be divided by the quality scale
• rated_operation_duration will be multiplied by the quality scale
• rated_ignitions will increase by a third of QualityScale percent
• rated_radiation will be multiplied by the quality scale