This document is focused on the management of the round robin study (RRS) and can provide guidance for the scope development, planning, and execution of the RRS study. It can provide guidance to identify the feedstock, machine operations, process controls, and post-processing operations prior to running the study. RR organizers can identify controlled and free parameters in the study. This document can also provide guidance on the selection and use of test methods that can be applicable. The RRS investigates the variations found in AM parts. The outcome of the study can be used to improve the maturation of AM technologies. A RRS, as described in this document, is different from an inter-laboratory comparison because an inter-laboratory study establishes the variability in a measurement method when undertaken by multiple users on a well-controlled artefact.