According to the PMBOK Guide, 7th edition, an agile project manager is a person who leads and facilitates an adaptive development approach, where requirements and solutions evolve through collaborative efforts of self-organizing and cross-functional teams and their customers. An agile project manager should use the following tools to estimate the time lines for delivery of the initial release:
Backlog grooming: This is a technique used to refine and prioritize the product backlog, which is a list of features and requirements that need to be delivered by the project team. Backlog grooming helps to ensure that the product backlog items are clear, concise, and ready for development. It also helps to estimate the effort and value of each item, and to align them with the product vision and customer needs.
Product backlog: This is the primary source of information for the project team and the product owner, who represents the voice of the customer and defines the product value. The product backlog contains the features and requirements that the project team will deliver in the form of product increments, which are potentially releasable outcomes that provide value to the customer. The product backlog is dynamic and changes as the project progresses and new information emerges.
Minimum viable product (MVP): This is the version of the product that has enough features to satisfy the customer's needs and provide feedback for future development. The MVP is the first product increment that the project team delivers to the customer, and it represents the minimum scope that the project must achieve. The MVP helps to validate the assumptions and hypotheses about the product value and customer satisfaction, and to guide the subsequent iterations and releases.