Company X is a company engaged in the PVC industry for High-Rise Building, industrial, residential, and warehousing projects throughout Indonesia. In its supply chain flow, the company faces problems such as mismatches in the amount and time of delivery of raw materials from suppliers, the discovery of defects in the raw materials supplied, and the high number of defective products in the production process, which reaches 26% per month. Pipe production activities produce waste in the supply chain flow, affecting the economic, social, and environmental pillars and the company’s sustainability index value. This research aims to map the supply chain flow in the company to provide suggestions for improvements to the performance of PVC pipe production using a sustainable lean supply chain approach. At first, Sustainable Value Stream Mapping (SUSVSM) was made for the company’s supply chain flow, followed by Process Activity Mapping to analyze Non-Value Added and waste in the pipe production supply chain flow. Identification of the causes of waste is carried out using the Ishikawa diagram. Furthermore, the Sustainability Index calculation is based on economic, social, and environmental indicators to measure the company’s sustainability performance. Proposed prevention actions based on the House of Risk (HoR) method are given to improve the sustainability index value. Proposed improvements based on the results of waste analysis and analysis of the causes of the gap between current conditions and targets to be achieved include identifying waste and determining proposed improvements to minimize waste and increase the value of the sustainable index. The proposed improvements are expected to increase the Process Cycle Efficiency (PCE) value from 57.22% to 67.85% and improve the Company’s Sustainability Index value of 118.4%.