This document outlines the GUEST methodology for applying lean principles to business development and innovation management projects. It consists of five steps: Go, Uniform, Evaluate, Solution, and Test. The Go step involves gathering information about the project from stakeholders. Uniform standardizes this information using a Solution Canvas tool. Evaluate builds models of the solution. Solution implements the solution. Test develops a test plan. The methodology is then illustrated through a case study on optimizing garbage collection routes and schedules to minimize costs. The key objectives, constraints, and an optimization model used are described.