In the COBIT 2019 implementation lifecycle, the phase where long-term targets should be adjusted based on experience is the evaluation phase, known as "Did we get there?". This phase involves assessing the results of the implemented governance and management practices to determine if the objectives have been met and to identify areas for improvement.

Detailed Explanation with References:

How do we get there? (Option A):

This phase focuses on developing and executing the plan to achieve the governance objectives. It involves identifying the steps, resources, and timeline needed to reach the desired state. While important for planning, this phase is more about action and implementation rather than evaluation and adjustment of long-term targets.

Where are we now? (Option B):

This phase involves assessing the current state of the governance system, identifying gaps, and understanding the baseline. It provides the foundational information needed to plan improvements but does not involve adjusting long-term targets.

What needs to be done? (Option C):

This phase is concerned with identifying the specific actions and initiatives required to address the gaps and achieve the governance objectives. It involves planning and prioritizing activities but not the evaluation and adjustment of long-term targets based on experience.

Did we get there? (Option D):

In this phase, the enterprise evaluates the outcomes of the implemented governance system against the set objectives and targets. It involves assessing whether the desired goals were achieved and analyzing the effectiveness of the governance practices. Based on this evaluation, the organization can adjust long-term targets to better align with practical experience, new insights, and evolving business needs. This phase is critical for continuous improvement and ensuring that the governance system remains relevant and effective over time.

According to the COBIT 2019 Implementation Guide, this phase includes reviewing performance metrics, stakeholder feedback, and lessons learned from the implementation process. These insights are then used to refine and adjust long-term targets to improve future performance and outcomes.

Conclusion:The correct answer isD. Did we get there?. This phase involves evaluating the results of the governance implementation, learning from the experience, and making necessary adjustments to long-term targets to ensure continuous improvement and alignment with the enterprise’s goals.