What is a key first step in developing a critical path method schedule?

Defining the execution plan is the foundational step in creating a CPM schedule. This involves understanding the project's scope of work and outlining how it will be executed to meet project objectives.

Option A (bar chart) is a visualization step but does not address planning the sequence or scope execution.

Option C (resources) comes later in schedule development after the scope and plan are defined.

Option D (logic diagram) is a subsequent step that relies on the execution plan​​.

The PSP Study Guide emphasizes scope and execution planning as critical first steps​.