This guide presents a checklist designed to assist organizations in initiating their modernization projects. It outlines essential steps to modernize architecture and infrastructure, aiming to simplify the digital transformation process. The first section emphasizes the importance of business discovery and analysis, suggesting the formation of a dedicated team to oversee the project and the definition of business use cases and requirements in collaboration with stakeholders. The guide also details the review of current architecture, including an assessment of existing systems and applications, identifying those that require replacement or retirement, and documenting their business purposes. Furthermore, it includes a section on creating future state architecture, which involves mapping transitional architectures and determining necessary integrations. The final part focuses on prioritizing modernization efforts, recommending the development of a phased modernization plan based on the identified priorities. This structured approach aims to streamline the modernization process and enhance organizational efficiency.