Analyzing measurement results of a target system. The analysis is performed by receiving a first matrix including first measurement results of the target system; training a matrix decomposition model with the first matrix to obtain a third matrix of normal or stable measurement results and a fourth matrix of anomalous or unstable measurement results; receiving a second matrix including second measurement results of the target system, wherein the second measurement results are later measurement results compared to the first measurement results; selecting from the third matrix a subset that matches with the second matrix; subtracting the selected subset from the second matrix to obtain a fifth matrix; outputting the fifth matrix or information derived from the fifth matrix for the purpose of evaluating performance of the target system.