System Design Process

Created:5/30/2020Last Updated:10/12/2020


New production introduction (NPI) involves many teams together to come up with a product that fits the market needs. The simplified steps includes following: first of all market requirements document (MRD) is generated from the market team; secondly, market requirements is translated into product requirements document (PRD), a list of features that the product should have,; lastly, an engineering requirements document (ERS) is created to address technical implementation to each feature list on the product requirements.

Design Steps Overview

General design steps:

  1. Generate a product requirements document (PRD) base user needs and wants (i.e product features lists)

  2. Translate product requirements to an engineering requirements specification (ERS) (i.e system requirements containing component list (plan of record POR) and system performance and constraints.)

  3. Translate engineering requirements to system architecture (i.e block diagram, power tree, clock tree, and physical design)

  4. Design and implementation (i.e schematic capture, board layout, and simulation)

  5. Come up with a system validation and verification plan for the system design (i.e SIPI validation, power system validation, basic functional validation, RF validation, Thermal validation, reliability validation, etc.)

  6. Test and update the design through multiple development iteration stages (i.e proto, evt, dvt, etc.) until engineering requirements are met.

Practical Example

MRD: A consumer friendly streaming dongle in development countries.


  1. A plan of record (POR) that lists the the main ICs used in the product

    • 2K streaming stick with 1 GByte of RAM and 8 GByte of Storage with only 2.4 GHz band WifI support. 1 meter long HDMI cable, and 5V 1A power usb power supply, 2x AAA remote control.

  2. Performance

    • Maximum Skin temperature

    • Range of remote

    • Keypress response latency

    • Battery life of remote

    • 4K60FPS streaming

  3. Compliances

    • HDMI 1.4, FCC, and CE compliance certifications

  4. Connectivity Standards

    • WLAN 802.11 b/g/n/ac

    • Bluetooth 5.0


  1. Components selection

    1. 2K resolution SoC selection, RAM selection, eMMC selection, layers of PCB board, WifI module selection with correct RF standard, thermal design and material selection, HDMI cable type selection, power supply vendor selection.

  2. Performance

    1. EMC requirements

      1. ESD test criteria

      2. Emission and Immunity criteria

      3. Surge/lighting criteria

    2. Power budget

      1. < 5W

    3. RF

      1. Link budget

      2. Rate vs. Range

      3. Peak Tx and RX throughput

        • conducted and radiated tests

      4. Competitive benchmark analysis

    4. SIPI (Signal integrity and Power integrity)

      1. Physical layer compliance for high speed digital interface such as USB3.0

      2. Power distribution network (PDN) for all critical power rails within the power tree.

    5. Thermal

      1. Max IC case temperature

      2. Max Skin temperature

    6. Reliability

      1. Drop test

      2. Vibration test

      3. Tumble test

      4. Environment test

System Architecture: Digital interface between SoC and its peripherals, power tree to all subsystem, clock tree to all subsystem, and physical layout floor plan for each subsystem.

Schematic Capture and Layout: Electrical system is drawing using EDA tool such as Cadence and Altium Designer.

Validation and Verification: Functional and physical layer test plan are enumerated per functional areas such as audio, RF, low speed digital interface, high speed digital interface, etc.

Summary & Conclusion

MRD: Outlines the why the market needs the product

PRD: Outlines the what the product features are based on market needs

ERS: Outlines the how the product features are met

System Architecture: Outlines electrical design implementation strategy for the ERS

Schematic Capture: Implementation of electrical system interconnect in terms of electrical symbols and wires.

Layout: Implementation of electrical system interconnect terms of real-world electrical component footprints and copper trace.

Validation and Verification: it's a test plan document that validates the architecture and test the design implementation based on performance and constraints from ERS.

Designing base on market product fits and product requirements are essential for system design engineers to make right trades offs on scope, schedule, and cost.