I. Case Background and Procurement Requirements In 2025, a municipal sanitation department (hereinafter referred to as 'Party A') publicly tendered for a batch of sewer cleaning vehicles to support urban drainage network and riverbed desilting operations. The tender specifications explicitly required: vehicles must be blue-plate registered and operable with a Class C1 driver’s license; tank capacity must be no less than 5 cubic meters; chassis must feature a Dongfeng single-cab configuration; and emission standard must comply with China VI. Following multiple rounds of evaluation, Chengli Special Purpose Vehicle Co., Ltd. delivered 10 units of the Dongfeng single-cab blue-plate 5-cubic-meter sewer cleaning trucks (corresponding to official model number CLW5070GSSD6). Party A reported that, prior to procurement, the department primarily relied on manual desilting and rented large-scale vacuum trucks—resulting in low efficiency, high operational costs, and prolonged project timelines. This procurement initiative aimed to enhance desilting efficiency through standardized equipment and reduce long-term operating expenses. In accordance with local procurement practices, the unit price for this project was approximately RMB 135,000 (based on publicly available tender information), with the total budget capped at RMB 1,493,000. II. Performance Comparison Before and After Deployment To clearly demonstrate the improvements brought by the new sewer cleaning trucks, we conducted a comparative analysis across three key dimensions: average daily operation volume, staffing requirements, and operating costs. Data sources include Party A’s operational statistics for 2024 (pre-procurement) and from June to December 2025 (post-procurement). Comparison Dimension Pre-Procurement (Manual + Rental) Post-Procurement (Chengli Sewer Cleaning Trucks) Improvement/Optimization Rate Notes Average Daily Desilting Volume (m³/day) Approx. 8–12 m³ Approx. 35–45 m³ ~3–4× increase Based on CLW5070GSSD6 official specifications; cycle time per operation significantly reduced Time per Operation (hours) Approx. 4–6 hours (including transport) Approx. 1.5–2 hours ~60% reduction Integrated lifting and self-unloading functions eliminate need for auxiliary machinery Required Personnel per Crew (persons) 5–7 persons (including driver, desilting workers, assistants) 2–3 persons (including driver, operator) ~50% reduction Automated operation reduces dependency on manual labor Annual Operating Cost (RMB 10,000/year) Approx. 50–60 (including rental fees, labor, fuel) Approx. 25–32 (including fuel, maintenance, depreciation) ~40–50% reduction Based on local procurement practice; excludes vehicle acquisition cost Annual Maintenance Cost (RMB 10,000/year) Approx. 8–10 (rental vehicle repairs) Approx. 3–5 (Chengli superstructure: lifetime after-sales service; chassis: nationwide warranty) ~50–60% reduction Chengli provides 24-hour direct parts delivery, minimizing downtime As shown in the table above, after deploying the Chengli sewer cleaning trucks, the average daily desilting volume increased from under 12 m³ to over 45 m³—a more than threefold improvement in efficiency. Time per operation decreased from 4–6 hours to under 2 hours, substantially shortening project cycles. Staffing requirements were optimized from 5–7 personnel per crew to just 2–3, reducing both labor costs and safety risks. In terms of operating costs, annual expenditures dropped from RMB 500,000–600,000 to RMB 250,000–320,000—a reduction of approximately 40–50%. These figures fully validate the significant benefits achieved through equipment modernization. III. Increase in Average Daily Operation Volume: From 'Slow Manual Excavation' to 'Fast Mechanical Suction' Prior to procurement, Party A mainly employed manual methods combined with