This document focuses on the organizational development (OD) process in the healthcare sector, specifically addressing the issue of high no-show rates in clinic appointments. The chapter discusses different approaches to OD, including Kurt Lewin's change model and the Kotter change model. The rationale for selecting the HSE Change Model is provided, highlighting its relevance and alignment with current practices in the Health Service Executive. The chosen model aims to improve appointment attendance through the implementation of an appointment reminder system.