Unlike manual assembly operations, reviewed research revealed that lean techniques have less potential when applied to automated production lines that are typically balanced with minimum human interaction. This paper explores the lean application to a fully automated production process of irrigation plastic pipes. The study first analyzes the automatic process flow, assesses its leanness, and utilizes Value Stream Mapping (VSM) and simulation to estimate its current state performance. The study then applies a set of lean techniques that are most relevant to the automated process. The impact of lean application in terms of reduced waste and losses is assessed using simulation and presented in a future state VSM. Simulation was found to be effective tool when utilized for lean application to automated processes. Results showed an overall process improvement in terms of pull strategy, product quality, and reduced changeover and the overall order lead-time.