The invention belongs to the
computer security field and specifically relates to a defect prediction method and a
system based on requirement change. The invention uses
software project history defect data and a
requirement document to construct a correlation set of requirements and defects, a requirement classifier classifies history requirements according to the correlated history defect attributive classification, calculates the requirement characteristic value of a requirement item and establishes an
SVM classifier; when new requirement change occurs, a requirement characteristic extractor extracts the requirement characteristic of the requirement, and a defect attribute predictor finds the requirement classification to which the predictor is belonged in the
SVM classifier according to the information of the requirement characteristic, consequently obtains the related defect attribute of the classification and completes the defect prediction. The invention can automatically add or delete the requirement characteristic classification to be extracted and modify the weights of these characteristics in a classification model so as to lead the obtained prediction model to be more accurate and improve the prediction accuracy. The
system can automatically complete prediction with directviewing prediction result.