SLI, a New Metric to determine Success of a Software Project

Project Management process plays a critical role in managing factors such as cost, time, technology and personnel towards achieving the success of a project and henceforth the sustainability of the company in the industrial market. This paper emphasizes empirical study of several projects developed over a period of time in a product and service based CMMI Level 5 Software Company. The investigation shows impact analysis of resources such as cost, time, and number of developers towards the successful completion of the project as allocated by the project manager during the developmental process. The analysis has further led to the introduction of a new qualitative metric, Success Level Index Metric (SLI) whose index value varies from 0 to 1. SLI acts as a maturity indicator that indicates the degree of maturity of the company in terms of success of their projects based on which the company can choose their desired level of success for their projects.

💡 Research Summary

The paper investigates how three classic project‑management resources—budget, schedule, and staffing—affect the success of software development initiatives within a highly mature (CMMI Level 5) organization. By extracting data from 32 projects carried out between 2015 and 2022, the authors quantify each resource as a ratio of actual to planned values (cost ratio = actual ÷ planned, schedule ratio = actual ÷ planned, staff ratio = actual ÷ planned). Success is defined as a binary outcome based on the simultaneous fulfillment of contractual quality criteria and customer acceptance tests.

Statistical analysis (Pearson correlation and multiple linear regression) reveals that cost overruns and schedule slips are negatively correlated with success, reducing the probability of a successful outcome by roughly 0.42 and 0.35 respectively. Staffing shows a non‑linear effect: a moderate team size (approximately 10–15 developers) maximizes success, while larger teams introduce communication overhead and diminish performance.

Guided by these findings, the authors propose a new qualitative metric called the Success Level Index (SLI). Each of the three resource ratios is first normalized to the interval