Discussion: To achieve a more reliable and accurate evaluation results, employ a systematic evaluation procedure instead of using a manual mental method to guess the answer for an analysis question. The modeler might attempt to use a mental or manual method of guessing the answer for an analysis question by tracing through the links without going through the systematic evaluation procedure presented in this section. While this method can produce some analysis results for relatively simple models, it is more difficult to produce sensible and consistent results for complex models. Therefore, the benefits of obtaining more accurate and traceable analysis results justify spending the time to evaluate i* models.