By applying a parametric modelling approach to pit design, experienced mining engineers can spend less time on routine drafting tasks required to produce safe, practical, and geotechnically compliant designs. This improved efficiency enables engineers to evaluate more options, generate greater value, and respond more quickly when circumstances change. This paper presents the parametric techniques for open pit mine design developed by RPM Global for their MINEPLANNER software. It summarises the key challenges encountered when creating a parametric model tailored to open pit geometry and how they were addressed. It also outlines the benefits reported by early adopters of the new approach.