According to NIST SP 800 64, what follows the decision to initiate system development?

The decision to initiate system development is followed by initiating the project and security planning. This step is crucial because it lays the groundwork for the entire development process, ensuring that security considerations are integrated from the start. Initiating the project entails gathering requirements, defining roles and responsibilities, allocating resources, and establishing the project's scope, which are essential for aligning development efforts with organizational goals and security requirements.

Security planning is involved at this stage to address potential risks and ensure that security measures are considered throughout the development lifecycle. This proactive approach ensures that security is not just an afterthought but is woven into the fabric of the development process, which is pivotal for achieving overall system integrity and protecting sensitive information.

While categorizing the information system, assessing business impact, and ensuring secure system development are all important components of the system development lifecycle, they occur either alongside or after the initiation of the project and security planning. The initiation phase is foundational, making the planning phase critical for the successful integration of security principles into the system development.