Patent ID: 7395519

Claim:
A computer readable medium having recorded thereon a program for analyzing an electronic-circuit, wherein said program allows a computer to execute: a circuit-information input step of inputting circuit information including an element model describing an electronic circuit; a changed-circuit detecting step of detecting an electronic circuit using a changed element model in the circuit information; an analysis-necessity deciding step of deciding whether waveform analysis is necessary by comparing a characteristic of an element model before change and a characteristic of the element model after change; and a determination-result processing step of displaying the result of deciding whether waveform analysis is necessary and making an instruction for waveform analysis of the electronic circuit using the element model after change for which it is determined that waveform analysis is necessary to cause the instruction to be executed; wherein, in the analysis-necessity deciding step, a voltage/current characteristic, a transient characteristic, and a frequency characteristic are calculated as the characteristics of the element model before change and the element model after change, a similarity value of each characteristic is calculated, when the similarity values of all characteristic are equal to or larger than predetermined thresholds, it is determined that waveform analysis is not necessary, and when the similarity value of any one of the characteristics is smaller than the relevant threshold, it is determined that waveform analysis is necessary.