How do I answer why do I need a PMO?

PMO (Project Management Office) may include both project management functions (standardizing project processes) and business functions (managing the business strategy). Relationship management requires connecting with key stakeholders, sponsors, and customers for communication and a consensus. The business strategy management requires the PMO to look at business objectives and prioritize projects in the portfolio. The PMO's focus should be driving business results. The PMO plays a vital role in any data science team. Here are three reasons why a PMO is critical for any data project:

1. Business context. A successful data project has to solve real business problems. The PMO manages the business relationship and communication to ensure the project stays in context. The PMO can also help team members focus on solving the correct issue and remain in line with the organizational strategy.
2. Execution. Data projects typically involve complex processes. Data science projects involving processes defined by the CRISP-DM model (cross-industry standard processing for data mining) are particularly complex. To execute the process, the team needs the PMO to ensure efficient and high-quality project delivery and navigate through organizations, mitigate the risks, and resolve problems. The PMO can also remind the team not to lose the big picture of creating an outcome.
3. Collaboration. No matter of discovering data, accessing data, or sending the data to the right place to process, data projects require much cross-team collaboration. A PMO can make communication efficient.

After years of managing data projects at major US corporations, I strongly recommend you to consider creating a PMO team side by side with data team for your projects.