Design For X Guidelines
- 1. Design for X
- 2. Design for X (DFX) refers to the use of a specific methodology to optimise a specific aspect of a design. The X represents the area of focus and approach. The DFX family is one of the most effective approaches to implementing concurrent engineering. While not every single approach can be implemented into a design, practicing these methods will improve your decision making, control over your design and confidence.
- 3. Design for Deployment The deployment of your designs is to aid in delivery, documentation readiness and ease of understanding by everyone. This includes, but not limited to: ➔ Designers ➔ Manufacturer ➔ End User What does this include? 1. Engineering Drawings 2. Product Design Specifications 3. Instructions
- 4. Product Design Specification ➔ Is the PDS ready for you to start designing? ➔ Can the PDS be handed over to another designer to continue the work? A PDS that only contains the Primary, Secondary, Optional Requirements will not be a suitable piece of documentation. These should be treated as a guideline. The PDS should cover 1. Performance 2. Life span 3. Environment 4. Weight 5. Packaging... http://www.jensen-consulting.co.uk/blog/writing-a-product-design-specification
- 5. Engineering Drawings The engineering drawings of your product is the most critical piece of documentation. You’re drawings should be designed to make reading and understanding your designs easy and clear. Engineering drawings must obviously include all relevant dimensions, however they should also include symmetrical dimensions, a revision history and tolerances. (See Example) Including symmetrical dimensions, tells the reader that these two aspects of the drawing are the same much quicker than them figuring it out. A revision history also tell the reader that changes have been made, which will ensure that they observe the drawing.
- 7. Repeated dimensions, reader will immediately know this is symetrical
- 8. All components are clearly laid out in the Bill of Materials (BOM) along with their quantity
- 9. A clear and simple revision history shows the the drawing has been changed, when it was changed and what was changed. This is critical when drawings are being passed over to a number of people.
- 10. Instructions The engineering drawings should provide all the information and instructions the designer and manufacture needs. Therefore, instructions should only be used for the end user. Before, issuing instructions for your product. Make sure that everything that can be simplified, is. The end user shouldn’t be taught how to hold, and use the product. The product design itself should demonstrate that. Use instructions to ensure the product is used to it’s full potential.
- 11. Design for Procurement Design for Procurement covers a number of aspects. The methodology behind is to reduce and optimise both initial cost and total cost of the product. To achieve this, the product should be designed with multiple sources of supply for all components, where possible. This is to ensure that if the first supplier fails, your product won't be jeopardised. Performing risk assessments on single sourced items and long lead items will reduce surprise costs. This should cover aspects such as quality, quantity and delivery time. Overall, reducing components and complexity from the product will minimise maintenance cost and improve reliability.
- 12. Design for Supply Chain As a designer, you should also take into account supply chain efficiency, inventory and to reduce lead times. This can be achieved by designing products for high assembly and manufacturing efficiency. Furthermore, designing products to reduce costs in packaging and transport will also aid the supply chain.
- 13. Design for Testability Design for Testability is a critical methodology, ensuring that testability features are added into the product design will allow you to find faults quicker. The idea behind adding testability features is to make development and manufacturing changes easier. The purpose of testability features is to validate the the product works and contains no defects that could, otherwise, affect the product's correct functioning.
- 14. Design for Flexibility Design the product to be scalable. The ease of expandability must be taken into consideration from concept to prototyping all the way through to manufacture. This can be achieved by designing the functions within the product to be easy to modify or to add new functions. If there are more products that need to be manufactured, design components to be flexible so they can be used on other products.
- 15. Design for Portability Not to be confused with physical probability. Design for Portability focuses on the modular aspect of the design. Design for portability increases testability for future changes, and makes developing and expanding the design easier and quicker.
- 16. Design for Reusability Design for Reusability should always be considered for each aspect of the design, especially for bespoke products. Designing with future reusability and optimization of the building blocks of the overall design will increase efficiency and reduce time. The best way to achieve this is to design products that can either be integrated into different products or reused for different applications. This methodology will also help you innovate, by being able to find different uses for products.
- 17. Design for Repairability The repairability of your product will ultimately determine its reliability and serviceability. When designing, consider what will happen if a part breaks, will the entire product become obsolete? Will this effect subassemblies? Or will you be able to make DIY repairs? The longevity of products such as cars and white goods benefit from deploying DFX methodologies. Overall, the easier a product is to repair, the lower the risk will be for the end user. Thus lowering prices and making your product more competitive in the marketplace.
- 18. Design for Regulatory Compliance Whatever it is you’re designing, you must always comply with regulations. Do not confuse these with standards. Majority of regulations focus on how the product will be used and what it’s intended purpose would be. Regulations are in place to ensure safe and effective products are delivered into the market place. Incorporating this methodology into the development process will save you both time and money compared to testing the finished manufactured product.
- 19. Design for Reliability Like most design practices, Design for reliability should start early in the design process. Knowing how to calculate reliability is important, but knowing how to achieve reliability is equally important. Performing tests such as stress-strain on the materials used and FMEA will help you calculate the reliability of your design and outline areas that failed. Furthermore, if your design includes moving parts, calculate how long these parts can move and operate until they fail.
- 20. Design for Safety Design for safety can be interpreted in two different ways. The obvious: Identifying and reducing health and safety risks through good design. Consider if the end product will be handled by small children, is it safe for them to use? The other aspect of safety is investment. Is your design safe for people to invest/sell? By removing any doubt within your design/product, people will feel safer to use it
- 21. Design for Quality Design for Quality not only focuses on the physical quality of the finished product but more so of the process quality. To achieve a quality product, you must use quality tools and processes. This includes all of the mentioned methodologies, as well as quality tools. So, go and get yourself a quality mechanical pencil to start off with!
- 22. Design for Cost Like most practices, Design for Cost covers a range of topics. However, it’s main objective is to obviously reduce cost. DfC covers areas such as materials, labour, manufacturing, assembly, supply and finance By designing each of these areas to reduce the overall cost will drastically reduce the overall cost to produce your design. Designing costing into your product develop early on will be difficult to ignore and remove later on, making it a vital part of the design
- 23. Design for Manufacturability Design for Manufacture is the most common practice when designing. The sole principle of DFM is to optimise your design for the manufacturing process that will produce your final product. When considering DfM these points should be covered: 1. Setup Time - How long will it take to set up, will the part need to be flipped to complete manufacture? 2. Material type - Softer metals are easy to manufacture. While most plastics are easy too, softer plastics will have machinability issue 3. Material form - Metals are either in bar form or sheet form, while plastics are usually in pellet form 4. Tolerances - Every material has different tolerances, In general the tighter the tolerance the more expensive designing will be 5. Design and shape - The volume and shape of the product will impact the manufacturability
- 24. Design for Assembly This is a simple practice. Design products that are easy to assemble. This means reducing the overall parts and designing parts that are easier to move, and grasp. Parts that are self positioning will drastically reduce assembly time and costs. Solidworks and other CAD software have built in tools that help with designing snap fittings and channels for aligning parts. Furthermore, they also have features that help you design flat pack fitting for one off designs. While more and more designs are getting complicated, they are requiring specialised machines like a 6-axis CNC. Using manufacturing methods like this, will allow the designer to essentially make the entire product within one part. However, while this is moving forward. There is also pressure on designers to consider the repairability of their designs.