A method includes providing a bearing housing configured to house a bearing, the bearing housing enclosing a free volume for receiving lubricant, providing a quantity of the lubricant in the free volume, and providing a sensor configured to measure at least one parameter affecting a degradation rate at which the lubricant will degrade and to produce at least one output signal indicative of the measured at least one parameter. The method also includes providing a pump for pumping lubricant into the bearing housing, providing a controller configured to receive the at least one output signal from the sensor and configured to control the pump based the received at least one output signal, and controlling the pump based on a function of the received at least one output signal.