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.

By using these tools, the agile project manager can estimate the time lines for delivery of the initial release based on the following factors:

The size and complexity of the product backlog items

The effort and value of each product backlog item

The capacity and velocity of the project team

The feedback and expectations of the customer

The dependencies and risks of the project

PMBOK Guide, 7th edition, page 19, section 1.2.2, Adaptive Development Approach

PMBOK Guide, 7th edition, page 20, section 1.2.3, Agile Project Environment

PMBOK Guide, 7th edition, page 21, section 1.2.4, Agile Principles

PMBOK Guide, 7th edition, page 23, section 1.2.5, Agile Team Roles

PMBOK Guide, 7th edition, page 25, section 1.2.6, Agile Practices

PMBOK Guide, 7th edition, page 149, section 5.2.3.1, Joint Requirements Session

PMBOK Guide, 7th edition, page 150, section 5.2.3.2, Facilitation

PMBOK Guide, 7th edition, page 237, section 8.2.3.1, Root Cause Analysis

PMBOK Guide, 7th edition, page 238, section 8.2.3.2, Quality Management Plan Updates

PMBOK Guide, 7th edition, page 33, section 1.3.2, Project Success

PMBOK Guide, 7th edition, page 34, section 1.3.3, Project Success Criteria and Objectives

PMBOK Guide, 7th edition, page 35, section 1.3.4, Project Success Measures

PMBOK Guide, 7th edition, page 37, section 1.4.1, Develop Project Charter

PMBOK Guide, 7th edition, page 38, section 1.4.1.3, Project Charter