Your design specification should include measurable statements (be able to test against) that will help you design with manufacture in mind. It needs to include enough detail to develop feasible design ideas that you could possibly make, but still leave room for creativity. 

Use the following checklist to help develop your product design specification.

These could also be titles of sub-sections when writing your specification:

·       The products purpose, function and aesthetics

·       User requirements and needs

·       The expected performance requirements of the product, materials and components

·       The kind of processes, technology and scale of production you may use

·       Any value issues that may influence your design, such as cultural, social, sustainable or environmental concerns

·       The use of renewable energy or materials

·       Any quality control and safety procedures that will constrain your design

·       Time, resource and cost constraints you will have to meet

Your design specification should guide all your design thinking and provide you with a starting point for generating design ideas. Your specification can change during the course of a project and develop as research is carried out, often starting as an outline specification until the final design or manufacturing specification is reached. This is used as a check when testing and evaluating design ideas and provides information about the solution that can help to monitor its quality of design. The design specification is an essential document that sets up the criteria for the design and development of your product and will be used at the end of your project for your Evaluation. 

Therefore, it is worth triple marks because if you do not have a good one you will lose marks for your Research, marks for your Design work and marks for your Evaluation! 

Your design specification needs to take into account designing for manufacture, where considerations for design should include the purpose, function, aesthetic and performance requirements of the product; materials, components or systems; market and user requirements; environmental concerns; energy implications; any values issues that may influence your design ideas and considerations about manufacturing processes, technology, scale of production; quality and safety issues; time, resource and cost constraints.

Title and Project Overview

Start with a clear title, such as "Design Specification for [your Project Name]." or just Design Specification. Include a brief summary to start (an explanation sentence) that defines the product that you are designing and its purpose (what it will do).

General Requirements

This section outlines the basic, non-negotiable aspects of your design.

• Aesthetics: Describe the desired look and feel. Use adjectives like "sleek," "modern," or "rustic." Mention colour schemes, textures, or a preferred finish.

• Target User: Who is this product for? Be specific about their age, needs, and lifestyle. For example, "This product is for urban commuters aged 25-40 who value portability and durability."

• Ergonomics: How will the user interact with the product? Specify aspects like weight, size, and the comfort of use.

• Life Cycle: Consider the product's journey from production to disposal. Include details on materials, manufacturing processes, and end-of-life considerations like recyclability. This is an opportunity to mention Environmental, Social, Moral and Ethical considerations.

Functional Requirements

List what the product must do. These are testable and measurable, and you will return back to them later in your Evaluation.

• Performance: Define how well the product should work. Use quantifiable metrics. Examples: "The device must have a battery life of at least 10 hours," or "The product must be able to withstand a drop from 1 meter without breaking."

• Key Features: List the specific functions of the product. Use bullet points for clarity. Example: "Must have a secure locking mechanism," or "Must be waterproof up to 1 meter for 30 minutes."

Constraints and Standards

Identify the limitations and mandatory rules your design must follow.

• Materials: Specify the type of materials to be used and any that are forbidden. Example: "Must be made from a non-toxic material" or "Must not contain PVC."

• Size and Weight: Provide a maximum or minimum for these parameters. Example: "Maximum dimensions: 150mmm x 100mm x 50mm."

• Budget: State the maximum manufacturing or material cost per unit. Ideally do this in THB and also add in a conversion to UK GBP.

• Safety and Regulations: List any relevant safety standards or legal requirements the product must meet (e.g., CE, RoHS, or FCC).

Research and Justification

Briefly connect your specification back to your initial research. Explain why each requirement is necessary.

• Link to Client Needs: Show how your specification points directly address the client's requests from your interview.

• Market Justification: Explain how your design fills a gap or improves upon existing products. This demonstrates that your decisions are evidence-based.