A computer-implemented method for determining the qualitative or quantitative susceptibility of a microorganism inoculum in a phenotypic antimicrobial susceptibility test using broth dilution, characterized in that the AST method comprises or consists of the following steps: a) Providing a microorganism inoculum and diluting the inoculum in a medium suitable for broth dilution AST, b) Providing a carrier comprising one or more compartments suitable for broth dilution AST, wherein the or at least part of the compartments comprise respectively a single antimicrobial agent or a combination of antimicrobial agents, c) Dispensing a sample of the medium containing the diluted inoculum of step a) into the or at least part of the compartments of the carrier of step b) so that the one or more inoculated compartments of the carrier comprise the respective test assays, d) Incubating the carrier of step c) comprising the respective one or more test assays, e) Measuring, during the incubation step d), at least n times for each of the one or more test assays with constant or inconstant frequency f a signal derived from a chemical or physical property of the inoculated microorganism, wherein the signal represents an essentially monotonic function of the number of the microorganisms in the measured test assay, and reading out corresponding values { x i} at corresponding recording times { t i}, wherein i represents the index number of the measurement represented by an integer 1 to n, and wherein n represents a full integer of 13 or more measurements, f) Estimating one or more slopes of linear trends α in data as a function of distribution of a difference from the subtraction of constituents of a pair of the readout values { x i} and { x j}, where j > i, divided by the time interval δt ij between taking readouts indexed i and j, whereby part or all of the n readout values { x i}, but at least 13 or more readout values { x i} at corresponding recording times { t i} are used for the distribution, and g) Determining the qualitative or quantitative susceptibility of the inoculated microorganism against the single antimicrobial agent or the combination of antimicrobial agents as a function of one or more slopes of linear trends α. a) Providing a microorganism inoculum and diluting the inoculum in a medium suitable for broth dilution AST, b) Providing a carrier comprising one or more compartments suitable for broth dilution AST, wherein the or at least part of the compartments comprise respectively a single antimicrobial agent or a combination of antimicrobial agents, c) Dispensing a sample of the medium containing the diluted inoculum of step a) into the or at least part of the compartments of the carrier of step b) so that the one or more inoculated compartments of the carrier comprise the respective test assays, d) Incubating the carrier of step c) comprising the respective one or more test assays, e) Measuring, during the incubation step d), at least n times for each of the one or more test assays with constant or inconstant frequency f a signal derived from a chemical or physical property of the inoculated microorganism, wherein the signal represents an essentially monotonic function of the number of the microorganisms in the measured test assay, and reading out corresponding values { x i} at corresponding recording times { t i}, wherein i represents the index number of the measurement represented by an integer 1 to n, and wherein n represents a full integer of 13 or more measurements, f) Estimating one or more slopes of linear trends α in data as a function of distribution of a difference from the subtraction of constituents of a pair of the readout values { x i} and { x j}, where j > i, divided by the time interval δt ij between taking readouts indexed i and j, whereby part or all of the n readout values { x i}, but at least 13 or more readout values { x i} at corresponding recording times { t i} are used for the distribution, and g) Determining the qualitative or quantitative susceptibility of the inoculated microorganism against the single antimicrobial agent or the combination of antimicrobial agents as a function of one or more slopes of linear trends α.