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Orchid Blog

5 Opportunities You Miss When You Don't Incorporate Design for Inspection

Posted: Tuesday, June 12, 2018

Design for Manufacturing (DFM) has increasingly been the focus of conversations between Original Equipment Manufacturers (OEMs) and Contract Manufacturers Organizations (CMOs) when creating a new product. Design for Inspection (DFI), however, is often overlooked, and is just as important as DFM in our highly regulated and cost challenged industry.  If you don’t consider DFI in the early stages of design, you risk losing its multiple benefits.

While DFM seeks a product that will be easy to manufacture, DFI seeks a product that is reasonable to inspect throughout the manufacturing process. Inspection is a buried fee that, if thought of too late, can increase the product’s manufacturing price. DFI can prevent that. Creating a product that can be easily inspected improves its repeatability, reduces manufacturing costs and can potentially eliminate the need for final inspection.

It’s important to discuss DFI with your supplier before you quote your project. You’ll miss the following opportunities if you don’t.

1. You’ll miss utilizing DFI as a driving factor during design

DFI shouldn’t be considered when a product is halfway through production; it should be considered from the beginning and help drive your design. It can be used to sort through all available options when determining the best features and specifications for your project. Critical issues are often found after a product is designed and completed, making it difficult to implement DFI. You’ll want to ensure your product will be able to be inspected before locking down your design. Incorporating DFI early in the design process uncovers potential issues before the product is in production and will lead to clear and repeatable inspection results.

2. You’ll miss assessing how GD&T and critical-to-quality features drive processes and cost

If you’re not sold on DFI, consider this: DFI can be used as a cost-savings tool. It’ll help uncover how complex features can add to the cost of your product, including geometrical dimensioning and tolerancing (GD&T). The use of unnecessary tight tolerancing and constrained GD&T can increase cost. Instead of over-tolerancing your parts, consider investigating what the true tolerance should be. You’ll save money because you’ll avoid adding unnecessary inspection for designs not requiring it. Understanding these complex features can also help you focus on cheaper, easier inspection methods. You’ll be able to avoid using high cost inspection systems for final inspection because DFI will help you create an easy to inspect product.

3. You’ll miss utilizing processes and run into inspection limitations.

DFI will allow you to better understand the repeatability and reproducibility of the product, tolerances during manufacturing and whether the demands of the product are reasonable. Issues that may be uncovered through DFI include how tolerances will affect the gauging system and its ability to detect nonconformances.  If the gauging system can’t withstand the small tolerance bands, this impacts the reproducibility and repeatability of the product and will result in the need for 100 percent inspection. Thanks to DFI, you’ll make sure that the dimensions of your product will have the ability to be inspected using standard methods in the industry which results in lower costs.

4. You’ll miss defining critical vs. non-critical features

Overlooking non-critical features is common practice when designing a product, but by doing so, you miss out on multiple opportunities. For instance, identifying non-critical features helps you look at the tolerances of your product in a different way. Instead of only looking at your tight tolerances, you’ll look at the non-critical tolerances and see how you can increase them which will lead to direct cost reductions. Additionally, by understanding which features are non-critical and designing inspection around them as well, you can make the manufacturing and inspection more efficient. It’s important to spend time prioritizing the features of your product or else you risk leaving money on the table based on your assumptions. Negotiations and changes won’t take place after the design is locked down, so make sure to identify its critical and non-critical features beforehand.

5. You’ll miss consistency across parts, systems and methods that result in lower piece price

Inconsistencies across methods will rack up the price of your product, but DFI can prevent that. Communicating with your manufacturer from the beginning will ensure you will use a consistent system throughout the product’s manufacturing processes. You don’t want to receive a computer aided design (CAD) model that may not convert to your manufacturing capabilities, resulting in having to rebuild it and additional costs. These additional costs include fixturings, gauging and study expenses. Consistency is also beneficial from a risk management perspective because the process will be more controllable.  In the end, this will help you create a product that yields high quality and low cost.


Design for inspection is most successful when implemented early in the design process.


By Quinn Alexander, Executive Assistant, Orchid Orthopedic Solutions


Contributors:
Matt Schultz, Sr. Product Development Engineer, Orchid Design
Rod Soat, Corporate Product Quality Manager, Orchid Orthopedic Solutions

For more information about Design for Inspection, read our article in Medical Design Briefs: 
Design for Inspection: The Key to Lower Cost and Higher Profit Margins