Weapon system programs often suffer from schedule slip and cost overrun associated with late or incomplete testing according to numerous analyses published by Government Accountability Office (GAO) and Department of Defense Office of Inspector General (DOD OIG). Most of the time, the success of DOD programs are hindered by unanticipated failures, found during testing and integration in the later part the program. The GAO claims that problems found late in the program development cycle are indicators of weak testing and evaluation processes. Addressing testing and evaluation errors in later stages of development life cycle can lead to schedule slip and cost overrun. Quantitative analysis of the benefits of uncovering issues early in the system development on the program performance is needed to help the decision maker implement adequate testing at the right time to improve overall DOD program outcome. This report reflects the results of a quantitative analysis conducted on the cost growth due to inadequate early testing utilizing cost data from selected acquisition reports. The analysis was done by performing a comparative analysis of the cost growth on two groups of programs: one with testing related issues and the other with non-test related issues. The purpose of this analysis is to statistically prove that early testing plays a major role in the success of systems development, so that decision makers can thoroughly examine the existing testing guidelines and implement the appropriate and adequate testing requirements early in the system development phase.