|Time analysis is a common approach for testing and detecting methods for the performance analysis of computer systems. In the article it is shown, that measuring and identifying performances based on a benchmark is not sufficient for the proper analysis of the computer systems behavior. The response time of the process is often composed of the execution of many subprocesses or many paths of execution. Under this assumption, it is presented, that both convolution and deconvolution methods can be helpful in obtaining time distributions and modeling of complex processes. In such a modeling the analysis of measurement errors is very important and was taken into consideration. The example of using the methods in buffering process is also discussed.