PMI’s CPMAI/PMI-CPMAI guidance emphasizes that, in the Data Understanding and Data Preparation phases, the team must identify appropriate datasets, evaluate training data requirements, validate “ground truth” quality, and explicitly assess data representativeness and potential bias issues before moving forward. Using historical data from multiple sources best supports representativeness because it increases coverage across operating conditions, environments, and failure modes that occur in real deployments (different fleets, sensors, maintenance practices, and duty cycles). This directly aligns with PMI’s expectation that the project manager ensures readiness of data for model development through quality checks and representativeness assessments as part of go/no-go decisioning. In contrast, relying solely on synthetic data can reduce fidelity and distort real-world distributions if not carefully validated; competitor data often has ownership and fit-for-purpose limitations; and real-time monitoring is useful operationally but does not inherently make the training dataset representative. Therefore, aggregating and reconciling multi-source historical data is the most PMI-aligned method to meet the objective of representative training data prior to model development and evaluation.