This document introduces five project methodologies - Lean, DMAIC, DMADV, DFSS, and PMI - and provides guidance on when each is appropriate to use. It explains the differences between efficiency and effectiveness, and how the methodologies focus on one or the other. A decision tree is presented to help determine which methodology to apply based on whether the project involves a new or existing process/output and is focused on effectiveness or efficiency. Readers are prompted to analyze past projects and potential future ones to practice applying the framework.