In Mianyang City and surrounding counties of Sichuan Province, as urban sewage treatment demands continue to grow, traditional fixed sewage treatment stations are increasingly unable to meet the requirements for rapid, flexible sludge cleaning and sewage transfer. In the second half of 2024, a municipal sanitation department collaborated with three subordinated subdistrict environmental maintenance units to launch a joint procurement initiative for 'Dongfeng Yizhan-style sewage treatment vehicles.' This article uses this case as a reference to deconstruct the entire process—from initial demand identification to final implementation—and integrates Chengli Special Purpose Vehicle’s product portfolio to provide procurement entities with actionable vehicle selection guidance. I. Background of Joint Procurement: Multi-County Pain Points Driving Demand The procuring entity was the Urban Management Bureau of a district in Mianyang City, whose jurisdiction includes three subdistricts that have long faced challenges such as high-frequency septic tank cleaning in aging residential communities, long-distance sewage transfer, and secondary pollution caused by conventional vacuum trucks. According to local procurement practices, if each subdistrict conducted separate tenders, the budget per vehicle would range from approximately ¥115,000 to ¥172,000; however, the combined requirement across the three subdistricts totaled four vehicles, with an aggregate budget exceeding ¥460,000. To enhance bargaining power and standardize operations and maintenance, the District Urban Management Bureau opted for a 'joint procurement' model—conducting a single tender, applying unified technical specifications, and implementing centralized acceptance. A distinctive feature of this procurement was the mandatory requirement for the 'Dongfeng Yizhan-style' configuration—i.e., a cargo box with side panels that lift upward, facilitating convenient maintenance and rapid loading/unloading, especially suitable for narrow access routes in aging residential neighborhoods. The vehicles were required to possess sewage suction, solid-liquid separation, automatic discharge, and high-pressure cleaning capabilities, while complying with China VI emission standards. According to publicly released tender information, the total project budget was capped at approximately ¥690,000, translating to an average unit price of around ¥150,000. II. Development of Unified Technical Specifications: From Requirements to Parameters To ensure fairness and quality in procurement, the Urban Management Bureau collaborated with technical experts to develop a detailed technical specification document. Key requirements included: Chassis Requirements: Dongfeng brand, China VI emission compliance, wheelbase approx. 3,300 mm—suitable for urban road operation. Upper-structure Requirements: Sewage tank capacity ≥ 3 m³, equipped with automated suction/discharge functionality and solid-liquid separation equipment; cargo box designed in Yizhan (wing-opening) style. Configuration Requirements: High-pressure cleaning gun, overflow alarm system, self-priming/self-discharging pump; tank interior requiring anti-corrosion treatment. After-sales Requirements: Nationwide chassis warranty; lifetime service coverage for upper-structure; spare parts delivery within 24 hours. These specifications closely align with Chengli’s CLW series. For example, the Chengli CLW5070GSSD6 model is built upon the Dongfeng DOLICA chassis, featuring a 3,308 mm wheelbase and an effective tank volume of 3.2 m³. It is equipped with a high-capacity vacuum pump and high-pressure cleaning system, fully satisfying all aforementioned technical parameters. Moreover, Chengli offers customized Yizhan-style cargo boxes to fulfill the specific requirement for 'rapid maintenance'. III. Centralized Tendering and Chengli’s Advantages in Bulk Supply Following open tendering, Chengli Special Purpose Vehicle Co., Ltd. secured the contract