A project manager is working on a software development project for an oil and gas...

In an agile software development project, especially one with many unknowns, iterative scheduling is the most appropriate method. This approach allows the project to be broken down into smaller sections, often referred to as sprints, which can be planned, executed, and reviewed in a cyclical manner. It accommodates changes and unknowns by allowing for adjustments after each iteration, ensuring that the project remains flexible and responsive to the client’s needs123. References:

“An Agile Approach to Scheduling” article1

Atlassian’s guide on "Creating Project Schedules: Steps & Techniques"2

“Agile Project Scheduling and Monitoring” from Open Colleges3