Modelling plays an important role in continuously operated plants as in chemical, metallurgical and aerospace fields, directly affecting subsequent researches of industrial processes. Rapid industrial development requires a high-quality model. Generally, external excitation is applied to the industrial process, ensuring the informative data for system identification. However, these processes are regularly operated to achieve a secure operation and to meet production objectives. For the safety and avoid violating product quality, external excitation can be forbidden or limited in the plant. Historical records are logged, which is natural to use them for analysis. These data are available at less, even no cost for identification. In this paper, based on the definition of information matrix and attenuating excitation, a detailed standard is aimed to propose to help extract informative data with respect to the chosen model structure to support system identification. The assessment of this standard is evaluated in a case, and the benefits are demonstrated, which ensures identification information enough, decreases information waste and achieves less, even no impact or cost of industrial processes.