Metrics to predict future modifications and defects based on software requirements specifications

In software development, the quality of the upstream process greatly affects the quality of the downstream process. However, few studies have applied metrics to estimate quality, controlled the quality quantitatively, or have verified the relationship between specifications and software quality. One reason is that specifications are described in natural language, making it difficult to quantitatively evaluate software metrics, such as complexity. Although high-quality software requirements specifications (SRSs) lead to successful implementation, neither a simple quantitative evaluation nor an effective indicator to predict modification-prone SRSs exists. Herein, the effectiveness of two specification metrics is evaluated (the number of pages and the number of previous modifications) in order to predict software defects and future modifications of SRSs. We confirm that both specification quality measured by specification metrics and software quality measured by the number of defects are related. We also reveal that future modifications are correlated with the size of SRSs.