Balu Mahesh 1. Design a system using a conductive water sensor (basically two metal probes that are very close together - when water is present between the probes it conducts) to detect when water level in a tank falls below 20% and when that happens, turn on a pump. The pump is a 3-phase 3-wire 1kW rated. This is for an industrial application where the water is being used for a chemical process. Design the system with some fail-safe such that the tank should never become empty. 2. Design summary is ok but could have been a little more detailed. Where is the fail-safe to prevent the tank from being completely empty? How do you prevent overflow? How do you prevent the motor from running when input supply is not present? What about when the pump fails? Basically there is no mention of the failsafe requirement. What are the tadeoffs? How are you balancing cost, efficiency, and reliability? What is the meaning of "Zero PCB or card board"? 3. Block diagram: what is roof of the tank? The top of the tank? Or is the tank on the roof of a building? The block diagram is confusing: what is the meaning of "exception?" Which of thse lines are signal and which are power?? 4. Power supply design is totally absent. 5. Industrial Design: Your text is directly lifted from https://sg.rs-online.com/web/c/enclosures-server-racks/enclosures/pcb-mounting-enclosures/ 6. KICAD Design Schematic: Did you use this circuit? even the values are identical: https://easyelectronicsproject.com/wp-content/uploads/2020/10/Water-Pump-Auto-Switch-Pic-12.jpg?x56667 PCB: Layout seems ok DRC is not passing because there is no outline. 7. Pricing / Assembly: Items costs are ok although grossly underestimated. No mention of materials for the actual probes, wiring, etc ???