Component 3 Creating a Prototype and Testing Plan - Overview

Preface

Prototype and Build Plan: A well-designed and well-built prototype will make testing and evaluation of the test data more realistic and valuable. Students typically view building the prototype as the most exciting step in the process and sometimes neglect or rush through the planning stage. However, a good plan will result in a better finished prototype. Because individual team members may have different ideas about how to build the prototype, teams should come to consensus on a step-by-step explanation of the assembly directions. Continued emphasis using brainstorming techniques will result in a better assembly procedure for their prototype. Well-written directions will provide better guidance for others who choose to continue research on the product and will result in more comparable prototypes if multiple models are built.

Testing: Why test at all? In engineering and science, a test is conducted to either prove a hypothesis or to answer a question. For instance, a tensile test can answer the question, “How much tension can this material safely withstand?” The strength of a material can only be determined by testing it under very precise and controlled circumstances. Or perhaps a skateboard deck was designed to withstand repetitive loading resulting from a 200 pound person jumping 24 in. high and landing on the deck over and over. Testing can help prove the hypothesis that the deck can safely withstand the design loads. In EDD, students will need to determine either what question they are trying to answer or how they can prove that their prototype performs as designed. Either way, it is important to identify exactly what data is needed and exactly how the test will be conducted.

Industry relies upon the American Standard Testing Methods (ASTM) and International Standards Organization (ISO) for testing procedures. Perhaps you have seen a company advertise that it is ISO 9001 certified – this means that the company has established a rigorous quality control of its materials and manufacturing processes that are internationally recognized.

If they can access the ASTM Standards, students can research testing methods. The actual documents are very expensive, so a visit to a local library may be necessary. If that is not possible, try to provide a copy of several test procedures for students to examine. Each organization has test procedures that cover most technical situations one might encounter. Many of these are extremely elaborate, costly, time consuming, and require expensive equipment operated by highly trained personnel. After showing students the national or global standard, you can allow them to use less rigorous tests. This will reinforce the importance of testing standards and industry accepted procedures but will allow more realistic testing situations in your classroom.

To yield useful results, students must first determine exactly what they are trying to discover or prove – they must define the test criteria based on the design specifications. Second, they must devise a test method that will allow them to safely gather data in a technically acceptable manner and that will demonstrate the success (or failure) of the design to meet the design specifications.

 

Understandings

  1. Relevant principles and practices of Science, Technology, Engineering, and Mathematics (STEM) should be used to inform and justify design choices.  They should be evident and well documented in an engineering design process. 
  2. Project management is the discipline of planning, organizing, motivating, utilizing resources to achieve specific goals.
  3. During the construction of a prototype, safety in the workplace is a critical component. All safety guidelines and procedures should be followed.
  4. Material, tools, and equipment requirements are defined by creating a materials and cost analysis before the construction of a prototype.
  5. A prototyping provides the engineer with a scaled working model of the design solution that can be tested.
  6. Engineers write step-by-step instructions for the prototype assembly to guide the fabrication of the design solution.
  7. Designers must consider characteristics such as strength and weight of materials and fastening procedures to be sure that the final design meets design specifications.
  8. Testing is a critical component to any engineering design process.  A plan and process for testing the proposed solution both qualitatively and quantitatively against design requirements should be created and carried out.
  9. Prototypes can generally be broken down into subsystems in order to isolate problems and conduct incremental testing.
  10. Prototype testing is a controlled procedure that is used to evaluate a specific aspect of a design solution.
  11. In order to gather useful data, specific criteria for success or failure of a test must be determined before testing begins.
  12. A detailed description of the testing procedure helps to ensure that the results of the design solution testing are valid.
  13. Data can be classified as either quantitative because it can be measured or qualitative because it describes a quality or categorization.
  14. The results of prototype testing are used to refine the design and to improve the design solution.
  15. A Critical Design Review are used to determine the quality and functionality of the final prototype. Designers should seek feedback from key stakeholders to determine if any modifications or improvements can be made before finalizing the testing process.

 

Knowledge and Skills
It is expected that students will...

  1. Document project progress in an engineering notebook.
  2. Create a step-by-step plan for building a prototype.
  3. Devise a list of testing criteria that will be used to evaluate the prototype and determine the success or failure of the design solution.
  4. Prepare a description of the testing method that will be used to validate and verify the design solution. 
  5. Construct a testable prototype.
  6. Select and describe a valid testing method that will be used to accurately evaluate the effectiveness of their design solution in solving the problem.
  7. Create a valid justification for the selected testing method.
  8. Design and implement a prototype testing procedure and data collection plan.
  9. Identify opportunities to incrementally test a prototype.
  10. Conduct testing of their prototype.
  11. Identify, define, and implement necessary modifications to testing methods based on expert feedback and ongoing research.
  12. Design and participate in a critical design review to evaluate their prototype and determine how their project will proceed to identify, define, and implement necessary modifications to their design based upon their test results.

 

Essential Questions

  1. Why is it important to have clear, concise directions for the assembly of a product?
  2. What steps can be taken to lower the cost of your prototype?
  3. How can I explain to others that if tested, the final prototype design or collection of individual segments representative of the complete solution idea will be able to yield real evidence of how well the idea meets each of the design requirements?
  4. Why are test criteria important in test design?
  5. What is the plan to test the prototype design and how can I show others that the testing plan for each design requirement is a well thought our test and would yield believable data?
  6. What measurement practices are used to analyze your test results?
  7. What did I learn from testing about how well this design met the stated design requirements?
  8. Why should others believe my/our analysis of the data?
  9. What is the significance of seeking input from experts or non-team members?

 

References

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