The Reliability of all modules reflects the Reliability of its Outputs. If any Output Reliability is not reliable, then the module Reliability must not be reliable.
The Pump Selector module checks the value of the Device nn Capacity property of all devices with indexes less than or equal to Number of Devices. If the capacity of any of the devices is zero, the reliability of the module is Configuration Error and the module does not execute.
For example, if Number of Devices = 3 and Device nn Capacity of devices 1, 2 or 3 is set to zero, then the reliability of the primitive is Configuration Error.