A method of assessing hole cleaning effectiveness of a drilling operation of a drilling system, comprising: a) determining a mass of cuttings removed from a well wherein determining the mass of cuttings removed from the well comprises: i) measuring a total mass of fluid entering the well; ii) measuring a total mass of fluid exiting the well; and iii) determining a difference between the total mass of fluid exiting the well and total mass of fluid entering the well; b) determining a mass of rock excavated in the well, comprising: producing at least one of an offset log, a logging while drilling log, or a formation bulk density log of the well; c) determining a mass of cuttings remaining in the well wherein determining the mass of cuttings remaining in the well comprises: determining a difference between the determined mass of rock excavated in the well and the determined mass of cuttings removed from the well; assessing at least one quantitative measure of hole cleaning effectiveness based on the determined mass of cuttings remaining in the well; the method further comprising: monitoring for a decrease in rheological properties of fluid in at least one point of the drilling system; assessing a water influx from at least one decrease in the rheological properties of the fluid: and adjusting the quantitative measure of hole cleaning effectiveness to account for the water influx. a) determining a mass of cuttings removed from a well wherein determining the mass of cuttings removed from the well comprises: i) measuring a total mass of fluid entering the well; ii) measuring a total mass of fluid exiting the well; and iii) determining a difference between the total mass of fluid exiting the well and total mass of fluid entering the well; i) measuring a total mass of fluid entering the well; ii) measuring a total mass of fluid exiting the well; and iii) determining a difference between the total mass of fluid exiting the well and total mass of fluid entering the well; b) determining a mass of rock excavated in the well, comprising: producing at least one of an offset log, a logging while drilling log, or a formation bulk density log of the well; c) determining a mass of cuttings remaining in the well wherein determining the mass of cuttings remaining in the well comprises: determining a difference between the determined mass of rock excavated in the well and the determined mass of cuttings removed from the well; assessing at least one quantitative measure of hole cleaning effectiveness based on the determined mass of cuttings remaining in the well; the method further comprising: monitoring for a decrease in rheological properties of fluid in at least one point of the drilling system; assessing a water influx from at least one decrease in the rheological properties of the fluid: and adjusting the quantitative measure of hole cleaning effectiveness to account for the water influx. monitoring for a decrease in rheological properties of fluid in at least one point of the drilling system; assessing a water influx from at least one decrease in the rheological properties of the fluid: and adjusting the quantitative measure of hole cleaning effectiveness to account for the water influx.