Which tool is primarily a graphical representation of a process's main steps and outputs?

The correct choice is indeed the process flow chart because it serves as a visual tool that maps out the main steps of a process along with their corresponding outputs. It provides a clear and concise graphical representation, which helps stakeholders understand the workflow, identify key steps, and visualize the flow of materials, information, or tasks within a process. This is particularly valuable in process analysis and improvement, as it allows for easier identification of bottlenecks or inefficiencies.

In contrast, a control chart is utilized for monitoring process stability over time by plotting data points and determining if a process is performing consistently within predefined limits. A cause and effect diagram, often referred to as a fishbone diagram, is used to identify potential causes of problems within a process, rather than mapping out the process steps themselves. A Pareto chart highlights the most significant factors in a dataset, typically displaying the frequency of issues in descending order, but it does not provide a flow representation of the process. Therefore, among the options provided, the process flow chart is distinctly focused on the representation of process steps and outputs.