A system analysis method includes: acquiring history information indicating, based on sensor values outputted by sensors, whether one of sensor values outputted by respective sensors indicates abnormality and/or whether individual relationship between sensor values outputted by different sensors indicates abnormality in time-series manner; estimating a change point group of change points, each indicating a time point system state has changed, based on history information; estimating relevance levels, each indicating relevance to the system state between two arbitrary time points included in the change point group; generating groups of change point groups by classifying the change point group into a plurality of groups based on the history information and the relevance levels; and generating and outputting output information, as information relating abnormality per group of the change point groups.