Developed a comprehensive LMM Cross-Software Comparison Guide for the PSIAIMS/CAMIS repository, focusing on clinical trial analyses using R and SAS. The guide detailed numerical optimization strategies, covariance model representations, and convergence behaviors, providing analysts with clear documentation of similarities and actionable differences between the two platforms. By leveraging R programming and statistical modeling expertise, the work improved reproducibility and reduced ambiguity in cross-language results. The documentation was integrated directly into the repository, enhancing onboarding and supporting multi-tool workflows. This contribution addressed the need for reliable, reproducible analysis in clinical trials and informed user guidance for both SAS and R implementations.