Design for Manufacturing (DFM) is the process of designing a product taking into account, from the very beginning, the manufacturing plant’s capabilities and availability of components and parts.
DFM aims to minimize the risk of errors and delays when a product is transitioning from prototyping to mass manufacturing. DFM also aims at optimizing design and cost and is vital to meet time to market.
Table of Contents
1. DFM IS NOT A SAUCE: CONSIDER DFM IN YOUR ARCHITECTURE
A tenet of Design For Manufacturing (DFM) is that 60% of the unit cost of a product is decided during architecture, and 20% in design. As they say at Toyota: ‘‘Skillful improvements at the planning and design stage are ten times more effective than at the manufacturing stage.’’
Designing your electronic product without close interaction with the factories in China & Taiwan who will manufacture it means you’re missing much crucial information, which necessarily means sub-optimal decisions.
If 95% of a product’s design is already done and validated, you can hire a brilliant China manufacturing consultant, but there is only so much they can do because 95% of the cost is frozen as well.
If you are Apple, you can demand that the factory invests in the exotic equipment upon which your Californian design is hinging.
But if you are starting with a 3K order, you need to accommodate the factory’s existing equipment, not the other way around.
Design for manufacturing rules #2
2. USE OFF-THE-SHELF COMPONENTS WHEREVER POSSIBLE
When it comes to design for manufacturing, standard components are key.
They’re readily available, with stable quality and dimensions, and so any engineer should use them wherever he can.
But somehow quite a few Western companies still wait eight weeks and pay a $250 K set-up fee for a custom LCD, when in China almost any display imaginable is readily available, mature and at a little cost.
It may seem quick to base your design on Digikey’s on-line catalog, but electronic product architecture done without the knowledge of China’s supply chain will never be DFM friendly; it leads to an uncompetitive BOM and will likely necessitate a drastic redesign later on.
3. NOBODY BEATS CHINA ON CUSTOM PARTS
Every electronic product will also need quite a few customs made parts, for example, the housing, and here the story gets even more compelling: China is unmatched in terms of speed, set-up, and unit cost for all parts which need to be customized or designed from scratch.
Not only are injection molds a lot cheaper and faster, but the same goes for PCB’s, batteries, cable trees, hinges, packaging…
Selecting vendors for custom parts is tricky as there are no ready-manufactured products you can compare on quality, price, and lead-time.
So when you’re new to China, and you want to ensure you’re accomplishing DFM, it’s often best to rely on recommendations, for example, from your Chinese assembly factory.
4. DO FINAL ASSEMBLY CLOSE TO YOUR VENDORS
Assembly is part of the DFM rules; some use DFM and DFMA (Design for Manufacturing and Assembly) interchangeably.
Each custom part is a new product, with prototypes and deviations to be worked out. When several first-run parts from different vendors need to play nice together in your assembly, the possibilities for problems multiply.
If you’re in Shenzhen, you can send a faulty batch right back, and receive new or reworked samples the next day.
Design adjustments will have to be made, and somehow most factories feel it’s more convenient if the other vendor takes on the hassle and expense of changing his molds, so quite a bit of negotiation is needed.
Having everybody around the same table, speaking Chinese helps tremendously to speed things up.
5. INVOLVE KEY SUPPLIERS EARLY IN THE DESIGN
There is no universal Design For Manufacturing (DFM) Guidelines. There is the only optimization for the particular factory which makes the part.
That’s one of the most important design for manufacturing rules to remember.
Ensure that each custom part of your design fits well with the machines, capabilities, and other preferences of the factory you’re working with, and you will save yourself much hassle later on. This past sentence perfectly encompasses what DFM is about.
But: factories will only invest their time in giving you input if they trust you to get the job.
Trust and mutual understanding need to be grown with time and physical proximity.
Rather than jumping to a different supplier to save a few cents we recommend very early involvement of a stable roster of suppliers close to the assembly factory; this will get you to a reliable product a lot faster.
6. FIND A RIGHT-SIZED FACTORY
As you know by now, knowing the factory you’ll work with is a big part of DFM, you simply can not do DFM if you don’t know who is going to manufacture your device.
The final assembly is where everything comes together, including any potential problems, so you need to find a manufacturer where you are important enough for the boss to show up when you visit.
Your annual buy should ideally not be less than 5% of their total sales. And be realistic about your forecast, a disappointing factory will quickly become decidedly less responsive.
Any project will have problems starting, the speed with which these will be resolved depends almost entirely on how important you are to the factory.
7. DON’T BANK ON A FACTORY PRIORITIZING DESIGN WORK
Every factory boss has one clear priority: keep production lines humming. Most factories do not have too many engineers, to begin with, and if a sizable production order has the slightest problem, the engineers will be assigned to fix that.
Working on the bugs of a new product which may, in 5 months perhaps, generate a first 3K order, which may or may not have a follow-up order, is not their top concern.
This is not short-sightedness specific to Chinese bosses; the manager of Jabil plant No.27 also needs to meet his quarterly targets.
No matter what, his top management says about supporting new ventures. If your “shared resource” PM also works for Cisco, it may take time to get your emails answered.
Remember one thing, a factory won’t have DFM in its mindset, it is your job to work on design for manufacturing.
8. PROTECT YOUR IP, BUT DON’T OVER-WORRY
Protecting our Client’s IP is a big thing at Titoma.
We employ quite a few strategies to ensure this, and since our start in 2002, we have yet to experience a problem.
At the same time, you should not exaggerate the risk. Not all inventions become mega sellers, and so nobody will invest time and money in copying a new, unproven product.
Once the product is a market success, everybody can have it copied. Manufacturing electronics in the US can work against you because of your higher retail price signals more margin potential for low-cost imitators.
9. RAMP UP CAREFULLY
If your Design for Manufacturing (DFM) process is robust, you should have a smooth transition into mass manufacturing; you must be careful though.
There is always much pressure to get a new product on the market ASAP, but ramping up step by step is the way to go if you want to avoid a Samsung style recall.
That case is an excellent example that no matter how much you test a product in your labs, there is nothing like having real pilot run samples in the hands of your actual end-users, Murphy’s law lurks in all sorts of dark corners, so start with 20 pcs, then 200 then 2,000.
Learn more about DFM in our DFM Hub.
ELON MUSK’S DFM RULES
1. Make requirements less dumb: find the person who wrote the requirement and ask him why.
2. Try hard to delete the part or process. Don’t leave stuff in for just in case, because you can come up with so many just in cases.
3. Simplify or Optimize.
4. Accelerate cycle time
5. Automate
The steps really need to be in this order.
– Do not optimize a part that should not be there.
– Do not accelerate digging your own grave.
Elon made the mistake of doing this backward multiple times, for example in his over-automated car factory.
Play this video to clients, coming from Musk
“your requirements are definitely dumb”
may go down a bit better.
DESIGN FOR MANUFACTURABILITY FAQ
HOW DO YOU DESIGN FOR MANUFACTURING?
These are the basic steps to design for manufacturing
1- Fully understand the capabilities of your manufacturing partner
2- Use already-manufactured components and parts
3- Get custom parts made in China as they’re quick and reliable
4- Involve key suppliers early in the design
5- Minimize the number of parts in the product
6- Leave some room for back up parts and/or electronic components
7- Make sure you use the same screws, fasteners or adhesives across the whole design
8- Follow experts’ guidelines
WHAT IS DFM AND DFA?
DFM stands for Design for Manufacturing. DFA stands for Design for Assembly.
In theory, DFM focuses on designing a product in such a way that its parts are easy to manufacture. DFA focuses on designing a product in such a way that putting it together is as easy as possible.
To learn more about the between DFM and DFA, check out our dedicated article.
WHY IS DESIGN FOR MANUFACTURING IMPORTANT?
Design for Manufacturing is important to avoid errors and delays when moving from prototypes to mass manufacturing.
Problems are likely to arise when scaling up production; if the only solution turns out to be a change in the design, your team will have to go back to the design table and start all over again.
This means you will have wasted a lot of time and resources and won’t meet your time to market.
That’s why design for manufacturing becomes imperative, if done correctly, you’ll include your manufacturing partners and other part suppliers early in the design stage, reducing manufacturing problems to the minimum.
WHAT IS DESIGN FOR MANUFACTURE AND ASSEMBLY?
Design for manufacture and assembly, or simply , DFMA , is the combination of two methodologies, DFM and DFA
DFMA aims to create a design that is easy to manufacture and assemble, simplifying the design structure is at the core of DFMA, this also reduces manufacturing and assembly costs.
