Select proper input ground motion based on site conditions. The input ground motion considered here is for rock-like soil conditions.

Choose coherency functions based on the knowledge of time lags between the locations per the site conditions.

The mesh size should be able to resolve the shortest wavelength.

Select a suitable region size based on the coherency model used, central frequency, and the problem type. The size of regions should be such that they capture motion incoherency and wave-passage effects.

Include a suitable number of modes in the analysis based on the cutoff frequency and the study of modal density.

Execute a few test runs using a minimal number of modes, as the cost of the analysis can grow rapidly. The growth ratio is governed by the number of regions (or more specifically, the number of PSD tables) to the power of 2, as well as the number of modes, also to the power of 2. The total analysis duration is therefore predictable after a single test run. Parallelization is recommended.