Explanation
According to the Implementation Roadmap article on the Scaled Agile Framework website, organizations begin realizing better results when following the Implementation Roadmap as soon as the first Program Increment (PI). The article states that "The first PI is a critical milestone. It's the first time the new ART delivers a fully integrated and tested increment of value. It's also the first time the ART demonstrates its new way of working to the enterprise and its stakeholders. The first PI is a big deal. It's a celebration of the new culture and the new way of working. It's also the first time the enterprise can see the benefits of the new approach." Therefore, the correct answer is B, as soon as the first Program Increment. The other options are not accurate, as the roadmap consists of more than just steps, training, or metrics. It is a continuous journey of learning and improvement.