This research delves into the critical aspects of information security during the implementation stage of the Software Development Life Cycle (SDLC). By employing a systematic literature review, the study synthesizes findings from various digital repositories, including IEEE Xplore, ACM Digital Library, Scopus, and ScienceDirect, to outline a comprehensive framework addressing the implementation stage's unique security challenges. This research contributes to the field by proposing a novel assurance model for software development vendors that focuses on enhancing information security measures during the implementation stage. The study's findings reveal 12 key steps organizations can adopt to mitigate security risks and enhance information security measures during this critical phase. These steps provide actionable insights and strategies tailored to support security protocols effectively. The article concludes that by incorporating these steps, organizations can significantly improve their security posture, ensuring the integrity and reliability of the software development process, particularly during the implementation stage. This approach not only addresses immediate security concerns but also sets a precedent for future research and practice in secure software development, particularly in the critical implementation stage of the SDLC.