Abstract: In problem situations of a computer controlling a process, such as transmission of calls, it is very important to direct the maintenance operations in the correct manner at the correct places as rapidly as possible. In the fault data collection method according to the invention, fault data is collected selectively by using empirical data about what type of information is useful in solving problems. Data (P10A-40A) about each process family is searched for from the list of process families PL in the data area (DA) of the computer's operating system. By means of the first process (P10) of the process family, data is obtained about the other processes (P11-P14) of the family. The data structures (PA) of the processes (P10-P14) provide data about the memory resources reserved by the process, time supervision, etc. By comparing the content of the data structures (PA) to the empirical base values, data structures (PA) are copied to the storage area (SA) from the process that are to be examined in greater detail.