How DFA Lowers Risk When Scaling Your Assembly

Published March 25, 2026
By David Kachoui and Jacob Huben

How to Scale with Safety, Quality, and Speed

The Major Pitfalls of Design Transfer

You’re ready to scale your assembly. You need to transfer the assembly process from your development team to your manufacturing team. But your manufacturers complain about being stuck with a design that is not scalable. Your manufacturers blame your designers, and your designers blame your manufacturers. Mistakes during design transfer can have a ripple effect that lasts for years or even decades. With all the finger-pointing back and forth, you have to play facilitator and make sure everyone works together to reach the optimal solution. 

Development teams get excited when the product finally works and want to jump straight into design freeze so they can move to production. The excitement when it does work is so high, and development teams are so fatigued, so financially strained, and so afraid to make any changes to a working product that they view DFA as something too expensive and too risky. They don’t plan for scale, so they skip DFA altogether. But skipping DFA is counterproductive. Decisions like this sacrifice safety, quality, and speed. 

Safety

Manufacturing challenges emerge during design transfer. Operators have difficulty achieving the same level of precision with the joining of mating components that the engineers were able to achieve. Manual operations repeated over a full shift for many days can contribute to health hazards. You want to uncover those safety risks by asking the right questions. 

Ergonomic Risks – If your engineers and scientists only make a handful of items, will ergonomic issues emerge once your operators manually perform the same motions over time? The risk of repetitive stress injuries for operators increases over time. Listening to feedback from the operators and making adjustments helps alleviate the risk. Cycling operator responsibilities help so they don’t perform the same isolated motion. Tools that perform repetitive motions that require strength can help alleviate the risk. 

Chemical Risks – If your assembly involves adhesives, can extended exposure create a health hazard for the people who make it over the long term? You can select safer materials or design out the chemicals from the process in the first place. If these are not options, process improvements can help, such as separating the operator from the fumes by adding venting or barriers. 

Mechanical Risks – If your assembly requires tools or equipment, does using it at higher speeds and higher quantities increase the likelihood of an operator making a mistake and causing injury? How well can you guarantee operators will not get hurt over the long term? Over time, new operators will join the assembly line and must be trained; can the process be altered to use safer tools and equipment to reduce the chance of injury by future new operators?  

Quality

Manual assembly operations can expose you to quality risks that remain invisible. During development at low quantities, moving slowly to get it right might be fine, but during manufacturing, operator speed grows critical, and quality risks escalate for the end user.  

Severity Risk – Can you adjust manual operations requiring high precision and operator judgment to make the correct assembly natural and less error-prone? The impact of a nonconforming part being accepted during development is far lower than that of nonconforming parts being accepted during production. In the worst-case scenario, the impact can be life and death for the end user. DFA activities should prioritize ways to reduce the likelihood of the most severe quality risks.  

Detectability Risk – Can you increase the detectability of nonconformances? Skilled engineers making a small number of parts will be more likely to be able to identify nonconforming parts during assembly than unskilled operators making a large number of parts at higher speeds. During DFA, you will want to make your nonconformances obvious. 

Rework Risk – Can you update the process, tools, and part design to ensure the assembly happens correctly the first time? Reworking quality errors during development might be acceptable, but during production, the impact of rework grows expensive by orders of magnitude. Rework increases the chance of additional quality errors.  

Speed

Speed allows you to scale. But premature scale and premature automation are the root of too many manufacturing evils. Speed-to-scale is at the forefront of the mind during the final stages of development. You want to achieve faster loading of the workpiece, faster orientation of the workpiece, faster alignment with the mating component, faster assembly, and faster ejection. Many DFA methods focus only on the part, but sometimes the design is already locked, or the tooling and equipment are already built. Manufacturers compensate by adjusting the tool or the operator, which is less desirable. The assembly typically scales from manual to tool-assisted to fully automated assembly. In other words, as you scale, the focus shifts from operator to tool to part.  

The Operator – What level of skill is necessary for correct assembly the first time? Do you have clear documentation on the procedures that are written for unskilled operators? Or do you have instructions written by highly skilled engineers for highly skilled engineers? What are the knowledge gaps, and what training is required to cover those gaps? The goal is to accelerate the learning process for the operators. 

The Tool – Do the tools fully support the operator? Is the right way obvious for operators? Can tools be used or improved to reduce the level of operator skill needed for consistently making good parts? Or do you require a high level of skills to know the right way? The goal is to lower the level of operator skill necessary while lowering the cycle time and quality reject rate.  

The Part – Is the correct assembly of parts obvious, natural, and designed to be done quickly and easily by a skilled person, an unskilled person, a human-assisted tool, and a fully automated tool?    

Conclusion

Too many companies fail to realize that assembling a small number of parts during development is very different from assembling high quantities with many people at high speed. Spending the time and resources to perform a proper DFA requires discipline and yields a high return on investment. You don’t want to fall into the trap of rushing your product into manufacturing just because “it works.” 

Incorporating Design for Assembly (DFA) during the design phase gives you the opportunity to design manufacturability into your product so your manufacturers can scale with confidence. Include the DFA phase in your project schedule, and budget for DFA adjustments to improve safety, quality, and speed, so you don’t get stuck with a part design that is not scalable. 

Your DFA process should simplify the product and reduce the operations necessary.

Remember: safety hazards impact quality, quality problems slow things down, and slowness raises costs. 

Let’s Build Your Assembly the Right Way from the Start

If you’re preparing to scale your assembly and want to eliminate risk in safety, quality, and speed, we can help you apply Design for Assembly the right way from day one.