A method for automatically relating system resource behaviour to transaction performance a system resource said method using monitor and a transaction performance monitor running on monitored servers, these monitors collecting on the basis of a periodic cycle respectively system resource metrics values and transaction performance metrics values, these monitors also detecting when system resource or transaction performance, metrics threshold values are exceeded, said method further using a management server, said method being characterized in that it comprises the steps of: - triggering from the transaction performance monitor, each time a transaction performance metric threshold value is exceeded, the system resource monitor for collecting system resource metrics values outside its periodic monitoring cycle; - at the management server, receiving system resource metrics values and transaction performance metrics values from the system resource monitor and the transaction performance monitor; - at the management server, performing the following additional method steps: - calculating, for a number of periodic monitoring cycles, the mean value of each periodically collected system resource metrics value; - calculating, for the same number of periodic monitoring cycles, the mean value of each system resource metrics value collected by the system monitor outside its periodic monitoring cycle; - identifying the system resource metrics for which there is a notable difference between mean values of system resource metrics values obtained by the system resource monitor outside its periodic monitoring cycle and mean values of system resource metrics values obtained by the system resource monitor on its periodic monitoring cycle; - setting new threshold values between the two calculated mean values for the identified system resource metrics. - triggering from the transaction performance monitor, each time a transaction performance metric threshold value is exceeded, the system resource monitor for collecting system resource metrics values outside its periodic monitoring cycle; - at the management server, receiving system resource metrics values and transaction performance metrics values from the system resource monitor and the transaction performance monitor; - at the management server, performing the following additional method steps: - calculating, for a number of periodic monitoring cycles, the mean value of each periodically collected system resource metrics value; - calculating, for the same number of periodic monitoring cycles, the mean value of each system resource metrics value collected by the system monitor outside its periodic monitoring cycle; - identifying the system resource metrics for which there is a notable difference between mean values of system resource metrics values obtained by the system resource monitor outside its periodic monitoring cycle and mean values of system resource metrics values obtained by the system resource monitor on its periodic monitoring cycle; - setting new threshold values between the two calculated mean values for the identified system resource metrics. - calculating, for a number of periodic monitoring cycles, the mean value of each periodically collected system resource metrics value; - calculating, for the same number of periodic monitoring cycles, the mean value of each system resource metrics value collected by the system monitor outside its periodic monitoring cycle; - identifying the system resource metrics for which there is a notable difference between mean values of system resource metrics values obtained by the system resource monitor outside its periodic monitoring cycle and mean values of system resource metrics values obtained by the system resource monitor on its periodic monitoring cycle; - setting new threshold values between the two calculated mean values for the identified system resource metrics.