A non-transitory computer-readable storage medium storing a program that causes a processor to execute a process. The process includes selecting a section from among a plurality of sections, performing on an input data group the time-series analysis from a top section to the section when each of a plurality of approximation application degrees is set in the section, based on a result of the performing, for each of the plurality of approximation application degrees is set, calculating an error and an index value for a result of the time-series analysis when an approximation calculation is not applied, the index value indicating a degree of speed-up, storing an approximation application degree in which the error falls within a range, and the index value obtained when the error falls within the range, and executing the time-series analysis on an another input data group by applying a combination of the approximation application degrees.