Design Document

Video Lecture

Video, Slides


The design document communicates the complete and detailed design of your project. It is substantially more detailed than the proposal and prepares you for the assembly phase of the semester. A quality design document is the key to a successful project. Use the following format.

  1. Introduction

    • Problem and Solution Overview:

      One to two paragraphs explaining the context of the problem to be solved by your project, including any relevant references to justify the existence and/or importance of the problem (i.e., the need or want for a solution). Justify the novelty of your solution or explain the expected improvements of your solution over previous results.

    • Visual Aid

      A pictorial representation of your project that puts your solution in context. Not necessarily restricted to your design. Include other external systems relevant to your project (e.g. if your solution connects to a phone via Bluetooth, draw a dotted line between your device and the phone). Note that this is not a block diagram and should explain how the solution is used, not a breakdown of inner components.

    • High-level requirements list:

      A list of three to four objective characteristics that this project must exhibit in order to solve the problem. These should be selected such that if any of these requirements were not met, the project would fail to solve the problem. Avoid vague requirements that can be interpreted a number of ways (e.g. "The radio subsystem should work reliably."). Each high-level requirement must be stated in complete sentences and displayed as a bulleted list.

  2. Design

    • Block Diagram:

      A general block diagram of the design of your solution. Each block should be as modular as possible and represent a subsystem of your design. In other words, they can be implemented independently and re-assembled later. The block diagram should be accompanied by a brief (1 paragraph) description of the high level design justifying that the design will satisfy the high-level requirements.

    • Physical Design (if applicable):

      A physical diagram of the project indicating things such as mechanical dimensions or placement of sensors and actuators. The physical diagram should also be accompanied by a brief one paragraph description.


      For each subsystem in your block diagram, you should include a highly detailed and quantitative block description. Each description must include a statement indicating how the block contributes to the overall design dictated by the high-level requirements. Any and all design decisions must be clearly justified. Any interfaces with other blocks must be defined clearly and quantitatively.

      Include any relevant supporting figures and data in order to clearly illustrate and justify the design. Typically a well justified block design will include some or all of the following items: Circuit schematics, simulations, calculations, measurements, flow charts, mechanical diagrams (e.g. CAD drawings, only necessary for mechanical components).

      You must include a Requirements and Verifications table. Please see the R&V page for guidance on writing requirements and verification procedures.

    • Tolerance Analysis: Through discussions with your TA, identify the block or interface critical to the success of your project that poses the most challenging requirement. Analyze it mathematically and show that it can be feasibly implemented and meet its requirements. See the Tolerance Analysis guide for further guidance.
  3. Cost and Schedule

    1. Cost Analysis: Include a cost analysis of the project by following the outline below. Include a list of any non-standard parts, lab equipment, shop services, etc., which will be needed with an estimated cost for each.
      • Labor: (For each partner in the project)
        Assume a reasonable salary
        ($/hour) x 2.5 x hours to complete = TOTAL
        Then total labor for all partners. It's a good idea to do some research into what a graduate from ECE at Illinois might typically make.
      • Parts: Include a table listing all parts (description, manufacturer, part #, quantity and cost) and quoted machine shop labor hours that will be needed to complete the project.
      • Sum of costs into a grand total
    2. Schedule:

      Include a time-table showing when each step in the expected sequence of design and construction work will be completed (general, by week), and how the tasks will be shared between the team members. (i.e. Select architecture, Design this, Design that, Buy parts, Assemble this, Assemble that, Prepare mock-up, Integrate prototype, Refine prototype, Test integrated system).

  4. Discussion of Ethics and Safety:

    1. Expand upon the ethical and safety issues raised in your proposal to ensure they are comprehensive. Add any ethical and safety concerns that arose since your proposal.
    2. Document procedures to mitigate the safety concerns of your project. For example, include a lab safety document for batteries, human/animal interfaces, aerial devices, high-power, chemicals, etc. Justify that your design decisions sufficiently protect both users and developers from unsafe conditions caused by your project.
      Projects dealing with flying vehicles, high voltage, or other high risk factors, will be required to produce a Safety Manual and demonstrate compliance with the safety manual at the time of demo.
  5. Citations:

    Any material obtained from websites, books, journal articles, or other sources not originally generated by the project team for this project must be appropriately attributed with properly cited sources. This means that even work the project team has done previously, as long as it was not done for this project, must be cited. Use IEEE format citations.


An example is available available to illustrate the expectations for a high quality Design Document: Sample DD.

Submission and Deadlines

Your design review document should be uploaded to PACE in PDF format by the deadline shown on the course calendar. If you have uploaded a DDC document to PACE, please make sure that it has been removed before uploading your Design Document.

Tea Blend Distributor

Zhenzuo Si, Zhiyuan Wang, Ruiqi Ye, Anyu Ying

Featured Project


- Zhenzuo si (zsi2)

- Ruiqi Ye (ruiqiye3)

- Zhiyuan Wang (zw39)

- Anyu Ying (anyuy2)


Tea is a popular beverage but cannot be easily obtained like coffee because no machine on the market can make it as convenient to drink tea as a coffee machine. Additionally, people’s requirements for the type and strength of tea are just as complex as those for coffee. We want to design a device that allows users to input the type of tea they want to drink and their taste preferences and then receive a cup of tea that meets their requirements.”


This machine has a total of five systems: an interactive subsystem that receives user input, a control subsystem that controls all other subsystems, a solid storage subsystem for storing tea leaves, a tea brewing subsystem that adds an appropriate amount of water at the right temperature, and a flavour subsystem for adding additional ingredients such as milk and sugar.



The interactive subsystem includes a series of digital displays and buttons for users to adjust parameters related to taste, such as tea strength, temperature, and concentration of additional ingredients. It is also capable of delivering this data to the control subsystem.


The control subsystem is capable of transmitting signals to other subsystems and can control the number of tea leaves and additional ingredients used, as well as the temperature and amount of water used, and the overall brewing time.


The tea brewing subsystem includes a mixing tank that can store the added tea leaves, water, and additional ingredients and can dispense the brewed tea and tea leaves together at the set time.


The flavouring subsystem includes tanks for storing syrup and milk, as well as pipelines and valves for adding a predetermined amount of syrup and milk based on instructions from the control subsystem.


After users set their taste preferences on the front-end interface, they can wait for a certain amount of time and then enjoy a cup of tea that meets their preferences. After each tea-making process, the machine’s interior is relatively clean and there are no residual tea leaves that could affect the taste or food safety.


Zhiyuan Wang is responsible for designing the mechanical structure, including the outer shell, storage compartment, and liquid pipelines. Anyu Ying is responsible for designing and soldering the circuit board. Zhenzuo Si and Ruiqi Ye are responsible for developing and debugging the control and interaction systems.