Design for assembly: 6 simple points to follow for reduced product complexity and cost.
6 simple points to follow to design out complexity and create products that are easier to make and build. This should be design common sense but is often forgotten about and could be damaging your bottom line.
When you’re designing or developing a product, it can be easy (and feel more exciting) to focus only on creating something that looks incredible with some obvious flashy features. I’ve seen concepts before for amazing products; they look sleek, they’ve got all the features a consumer could ever want and it perfectly meets the design spec. It’s usually shortly after this grand moment that things begin to unravel. You realise that you can’t access half the bolts with a standard tool, you’ll need to source fixings from 27 different suppliers (some in DIN spec, some in BS spec and one spurious little screw in an imperial ANSI spec because “it looked better”) and the casing of the product will cost 3 times your entire budget because aerospace grade titanium was used in order to meet the vague product requirement of ‘must be strong’. What’s more, you find that when you come to do an assembly trial that some parts are so awkward and fiddly to assemble that you need some poor person to spend half a day using special jigs, a magnifying glass and a set of tweezers to build the thing.
Obviously there’s exaggeration here, but hopefully you see the point. If you don’t take the time during the design and development phase to do these following things, you could end up paying way over the odds in materials, manufacture processes and assembly time:
Be clear on your product requirements. Vague and rambling product requirements make it difficult for the designer to begin with as they’re not clear on what the product needs to achieve. Requirements as a minimum need to be specific and measurable. Instead of ‘must be strong’, try ‘must survive an impact force of 100N onto the front face without plastic deformation’.
Reduce the number of parts. If you can get away with fewer parts without impacting product function, do it. You’d only be paying extra for someone to fit things together otherwise. You could merge smaller parts, replace 4 bolts with 2 larger bolts, replace screws with snap fittings, etc.
Commonise parts. Make your product modular, use the same type of fitting, make similar parts identical. There are lots of ways to do this, but all of them will reduce the demands on storing and managing unique parts, finding the right part, finding the right supplier and minimising the number of tools needed. The result is a lower assembly cost and potentially a lower materials cost through economies of scale.
Use common or standard materials. If your material choices are readily available off the shelf from multiple suppliers, then your lead times will likely be lower and your costs will likely be lower. Avoid specifying custom or rare spec parts if a standard one would do just as well.
Make sure your tools fit. This can’t be overstressed enough, make sure standard and common tools fit into where the fixings are in your product. Custom or rare tooling adds production cost and potentially increases the risk of assembly errors as operators won’t be used to using them.
Make sure parts can be manufactured using standard processes. 3D printing allows any shape to be made. That unfortunately doesn’t translate to an injection moulding machine or CNC machine. Having complex shapes with overhangs in the line of draw or undercuts makes manufacturing more difficult and hence more expensive. Make sure to consider how you’re going to manufacture the part as you design it and remember that just because you can design it, doesn’t mean you can make it.
Keeping the above points in mind can really help with reducing manufacture and assembly complexity. More importantly for your finance team, designing with the above ethos in mind means your product cost price will be lower and your profit margins likely higher.
Get in touch with us today to see how we can help you design and develop your products to be easier (and cheaper) to produce.
