Computer-implemented method for determining a net throughput time between process steps of a process instance in a computer system which has a processor, wherein a memory device is operatively coupled to the processor of the computer system, wherein the process instance comprises a number of process steps which comprise the process steps between which the net throughput time is determined, wherein at least one unique identifier and one time indication are stored for each process step, wherein each process step is stored as a data record in a process log in the memory device of the computer system according to a predetermined data structure, wherein the memory device is a main memory, wherein - the predetermined data structure at least comprises: - a first attribute in which a unique identifier of the process instance of the relevant process step is stored; - a second attribute in which the unique identifier of the relevant process step is stored; and - a third attribute in which, using the time indication, the sequence of the process steps within a process instance is stored; wherein, in the data structure, the process steps belonging to a process instance are stored in the main memory at adjacent addresses so as to be sorted according to the third attribute, - the processor uses a calendar to determine the net throughput time of the process instance, in which calendar a number of time intervals are stored which are to be taken into account when determining the net throughput time, and processes the process steps in a stream, sequentially and in the correct sequence, - the processor carries out a comparison between the time indications stored for the process steps and the time intervals stored in the calendar, wherein a net throughput time between two process steps is calculated after the comparison. - the predetermined data structure at least comprises: - a first attribute in which a unique identifier of the process instance of the relevant process step is stored; - a second attribute in which the unique identifier of the relevant process step is stored; and - a third attribute in which, using the time indication, the sequence of the process steps within a process instance is stored; wherein, in the data structure, the process steps belonging to a process instance are stored in the main memory at adjacent addresses so as to be sorted according to the third attribute, - a first attribute in which a unique identifier of the process instance of the relevant process step is stored; - a second attribute in which the unique identifier of the relevant process step is stored; and - a third attribute in which, using the time indication, the sequence of the process steps within a process instance is stored; wherein, in the data structure, the process steps belonging to a process instance are stored in the main memory at adjacent addresses so as to be sorted according to the third attribute, - the processor uses a calendar to determine the net throughput time of the process instance, in which calendar a number of time intervals are stored which are to be taken into account when determining the net throughput time, and processes the process steps in a stream, sequentially and in the correct sequence, - the processor carries out a comparison between the time indications stored for the process steps and the time intervals stored in the calendar, wherein a net throughput time between two process steps is calculated after the comparison.