What marks the beginning of the Continuous Delivery Pipeline?

According to the SAFe DevOps Practitioner 6.0 study guide1, the Continuous Delivery Pipeline (CDP) represents the workflows, activities, and automation needed to guide new functionality from ideation to an on-demand release of value. The CDP consists of four aspects: Continuous Exploration (CE), Continuous Integration (CI), Continuous Deployment (CD), and Release on Demand. The CDP enables organizations to deliver new functionality to users far more frequently than traditional processes. The first step in the CDP is Continuous Exploration, which focuses on creating alignment on what needs to be built. In CE, design thinking ensures the enterprise understands the market problem or customer need and the solution required to meet that need. It starts with a hypothesis of something that will provide value to customers. Therefore, an idea marks the beginning of the CDP in CE.