Lesson Notes By Weeks and Term v4 - SHS 3
Design and Drawing for Manufacture
Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.
Design and Drawing for Manufacture
Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.
Subject: Manufacturing Engineering
Class: SHS 3
Term: 1st Term
Week: 4
Grade code: 1.2.1.LI.3
Strand code: 2
Sub-strand code: 1
Content standard code: 1.2.1.CS.1
Indicator code: 1.2.1.LI.3
Theme: Design and Prototyping
Subtheme: Design and Drawing for Manufacture
This page supports the lesson note with a companion video and a short classroom-ready summary.
For class groups and homework, share this lesson page so learners also get the summary, objectives, and full lesson context.
This lesson introduces the Design Process, a systematic and iterative series of steps that engineers and designers use to solve problems. In Ghana, from the artisan crafting a new stool in Ahwiaa to the engineer designing a new fufu-pounding machine, this process is the backbone of all creation and innovation. Understanding this process is crucial for manufacturing because it helps ensure that products are not only functional and well-made but also that they truly meet the needs of the people who will use them. It helps us move from a simple idea or a community problem to a tangible, tested solution, saving time, money, and resources along the way.
The Design Process is not a rigid, linear path but a cyclical framework. This means you often have to go back to an earlier step to make improvements. It is a journey from identifying a problem to creating and refining a solution.
Let's explore the eight key stages using a problem every SHS student understands: "Carrying many heavy textbooks and notebooks to and from school is uncomfortable and causes back strain." Stage 1: Define the Problem What it is: This is the most critical stage. It involves clearly and specifically stating the problem you are trying to solve. A poor problem definition leads to a poor solution. Why it's important: If you don't fully understand the problem, you might solve the wrong thing. You need to identify the *root cause*, not just the symptoms. Example (Carrying Books): *Weak Definition:* "Students need a new bag." (This assumes a bag is the only solution). *Strong Definition:* "SHS day students need a more ergonomic and efficient way to transport up to six textbooks, four notebooks, a mathematical set, and a lunch pack daily, without causing back or shoulder pain and while protecting the items from rain." This definition is specific about the user (SHS day students), the load, and the key requirements (ergonomics, weather protection). Stage 2: Research and Ask Questions What it is: Gathering information to fully understand the problem and its context. This involves asking questions, observing users, and looking at existing solutions. Why it's important: Research prevents you from "reinventing the wheel." It provides inspiration and helps you understand the constraints (e.g., cost, available materials). Example (Carrying Books): *Questions to Ask:* How much do the books weigh? What is the average distance a student walks? What materials are affordable and available in the local market (e.g., Makola, Kejetia)? What features do students like or dislike about their current bags? *Research Activities:* Interview fellow students. Weigh a typical set of books. Go to the market to check prices of canvas, zips, and straps. Look at different types of bags online and in shops. Stage 3: Brainstorming Potential Solutions (Ideation) What it is: Generating a wide variety of ideas, without judgment or criticism. The goal is quantity over quality at this stage. Think freely and creatively. Why it's important: The first idea is rarely the best one. Brainstorming helps you explore many different possibilities before settling on one. Example (Carrying Books): Idea 1: The "Super-Backpack" - A backpack with extra-wide, padded straps, a rigid back support, and multiple compartments to distribute weight evenly. Idea 2: The "Scholar's Trolley" - A small, lightweight wheeled trolley that can be pulled, removing all weight from the back. Idea 3: The "Modular Binder System" - A system where students only carry the specific chapters they need for the day in a lightweight binder, leaving the main textbooks at home or in a locker. Stage 4: Decide on a Solution (Selection) What it is: Evaluating the brainstormed ideas against a set of criteria to choose the most promising one to develop further. Why it's important: This ensures the chosen solution is the best fit for the problem based on logic and evidence, not just personal preference. A tool called an Evaluation Matrix is very helpful here. Example (Using an Evaluation Matrix): Criteria: Let's choose criteria based on our problem definition: Cost, Durability, Comfort, and Weather Protection. We'll score each idea from 1 (poor) to 5 (excellent).
| Criteria | Idea 1: Super-Backpack | Idea 2: Scholar's Trolley | Idea 3: Modular Binder System | | :--- | :---: | :---: | :---: | | Low Cost to Make | 3 | 2 (wheels are expensive) | 4 (photocopying costs) | | Durability | 4 | 3 (wheels can break on bad roads) | 2 (paper is fragile) | | Comfort | 4 | 5 (no weight on back) | 5 (very lightweight) | | Weather Protection | 4 | 3 (books might get splashed) | 2 (paper easily damaged by water) | | TOTAL SCORE | 15 | 13 | 13 | Conclusion: Based on this matrix, the Super-Backpack is the most balanced solution and the best one to develop further. Stage 5: Develop the Solution What it is: Taking the chosen concept and turning it into a detailed plan. This involves creating detailed drawings (orthographic projections, assembly drawings), selecting specific materials, and planning the manufacturing steps. Why it's important: A detailed plan acts as a guide for building the product. It ensures that anyone building it knows exactly what to do. Example (Super-Backpack): Create drawings showing the exact dimensions of each part, specify the type of canvas and thread to use, and list the steps: cut fabric, sew pockets, attach straps, insert zips, etc. Stage 6: Make a Prototype What it is: Building a first-version, functional model of the product. A prototype can be made from cheaper materials (e.g., cardboard and tape) or from the actual intended materials. Why it's important: It allows you to see and interact with your design in the real world for the first time. It helps you find problems that you couldn't see on paper. Example (Super-Backpack): Sew a real backpack using the drawings from Stage 5. It doesn't have to be perfect, but it must be functional enough to be tested. Stage 7: Test the Prototype What it is: Putting the prototype to use in real-world conditions to see how well it works. Why it's important: Testing provides valuable feedback on what works and what doesn't. This is where your assumptions are checked against reality. Example (Super-Backpack): Get five different students to load the prototype with their actual books and use it for a full school day. Ask them to fill out a feedback form: Were the straps comfortable? Was it easy to organize the books? Did anything break? Stage 8: Improve the Design (Iterate) What it is: Using the feedback from testing to make changes and improvements to the design. Why it's important: Design is a cycle. Almost no product is perfect the first time. Iteration is the process of refining the solution to make it better. Example (Super-Backpack): The test feedback shows that the side pocket for the water bottle is too small. Improvement: Go back to Stage 5 (Develop), update the drawing to show a larger pocket, and modify the prototype (Stage 6). You might test it again to be sure the new pocket is right.
Guided Practice (With Solutions)