An Engineer’s Guide to Design for Manufacturing (DFM)

Bringing a product to life is no small feat. But even the smartest design can fall apart if it’s too complex to assemble, requires hard-to-source materials, or demands ultra-tight tolerances that drive up costs. That’s where design for manufacturing (DFM) comes in.

As experienced industrial designers and mechanical engineers, we’ve worked on products across industries and seen how early, thoughtful DFM can mean the difference between a smooth launch and a costly backtrack. Done right, it reduces production headaches, lowers costs, and helps you ship a product that meets your quality and performance goals.

In this guide, we’ll walk you through the DFM strategies we rely on every day: practical best practices, avoidable mistakes, and how to design with manufacturing in mind.

Table of contents:

• What Is Design for Manufacturing?
• DFM Benefits
• Design for Manufacturing Principles
• DFM Best Practices
• Examples of Design for Manufacturing
• FAQ

What Is Design for Manufacturing?

Design for Manufacturing, or DFM, is the process of examining how to make a product easier, faster, and more cost-effective to produce without compromising on quality or functionality. This process involves considering various factors such as materials, manufacturing methods, assembly techniques, and the capabilities of the production facility.

DFM isn’t just a one-time activity — it’s a proactive, iterative process that spans the entire product development lifecycle. It starts with the initial concept and continues through design, engineering, prototyping, and production. At each stage, DFM considerations play a crucial role in shaping the product’s design and ensuring its successful transition from concept to reality.

At StudioRed, we often start DFM conversations before a project officially kicks off. By considering manufacturing constraints and opportunities early, we can save significant time and money down the road.

Design for Manufacturing vs. Design for Assembly

Design for manufacturing and design for assembly (DFA) often get lumped together, but they tackle different challenges in the product development process.

• DFM is about making each individual part easy and cost-effective to produce. It considers things like material choice, manufacturability, tolerances, and tooling.

• DFA, on the other hand, is about making the entire product easier to put together. It focuses on reducing part count, simplifying interactions between parts, and cutting down on time and labor during assembly.

Together, they form DFMA (design for manufacturing and assembly), a more complete design strategy that reduces costs and speeds up production.

Benefits of DFM

Implementing DFM principles can have a massive impact on the success of a product. Here are some of the key benefits we’ve experienced firsthand:

• Lower production costs: Optimizing designs for manufacturing can reduce material usage, minimize waste, and streamline production processes. This can lead to significant cost savings, especially when onshoring manufacturing.
• Reduced risk: DFM helps catch and correct potential manufacturing issues early before they turn into expensive production problems.
• Faster time to market: Considering manufacturing early on helps avoid major redesigns later in development. This can shave weeks or months off product launch timelines.
• Improved product quality: DFM helps eliminate design features that are prone to defects or variability in manufacturing. The result is more consistent, higher-quality products.
• Enhanced reliability and maintainability: DFM principles often lead to simpler designs with fewer parts. This typically results in reliable products that are easier to maintain, service, and repair over their lifetime.
• Increased production flexibility: A DFM-optimized design can be more easily adapted to different manufacturing processes and scaled up or down as needed.
• Improved communication and collaboration: DFM fosters better communication and teamwork between design, engineering, and manufacturing teams.
• Increased innovation: DFM encourages creative problem-solving to optimize designs, often leading to innovative solutions.
• Improved sustainability: Optimizing material usage and manufacturing processes can reduce waste and energy consumption.
• Greater customer satisfaction: By offering higher-quality products delivered faster and at lower costs, you can exceed your customers’ expectations and boost loyalty.

DFM and the Product Development Lifecycle

From concept sketches to production-ready files, applying DFM early and often helps catch issues before they become expensive mistakes. Let’s break down how DFM fits into each phase of the process.

Initial Concept

Even in the early brainstorming phase, DFM should be on your radar. This process is when you make high-level decisions about product size, materials, and functionality — choices that can lock you into (or out of) certain manufacturing methods later on. 

Thinking about how something might be built, even roughly, helps avoid design dead ends and keeps development grounded in reality.

Design

As the concept evolves into actual CAD models, DFM becomes more hands-on. Now’s the time to start applying manufacturing constraints like minimum wall thickness, draft angles, and material-specific limitations. It’s also when engineers should loop in manufacturing partners to get early feedback and flag features that might complicate tooling, machining, or molding.

Prototyping

Prototypes are a testbed for how well your design plays with real-world manufacturing. At this stage, aim to build your prototype using processes and materials as close to final production as possible — for example, CNC machined parts instead of 3D prints if you’re prepping for injection molding. 

Actively test for DFM issues by checking assembly fit, simulating tolerances, and doing dry runs of the assembly process. Look for red flags like misalignments, fasteners that are hard to reach, or features that require overly precise tooling. These insights can help simplify or re-spec components before locking in your design.

Production

Once you move into production, DFM choices directly impact how fast, reliably, and affordably a manufacturer can make your product. For example, if your design includes tight corners or deep cavities, they might need extra machining steps or custom tooling — adding time and cost. 

During early production runs, work with your supplier to spot bottlenecks: Are parts taking too long to assemble? Are certain features causing defects or rework? 

You can often simplify things, like switching to snap fits instead of screws or increasing draft angles for easier molding. This is the time to lock in any final tweaks that make high-volume manufacturing more consistent and less error-prone.

Design for Manufacturing Principles 

By understanding and applying DFM’s core principles, you can create designs optimized for efficient, high-quality production. These principles form the foundation of our approach to DFM at StudioRed and have proven invaluable in countless projects.

1. Minimize Part Count

Think of product development as a puzzle — the fewer pieces there are, the easier it is to put together. The same concept applies to manufacturing. Each part of your product represents a potential point of complexity, cost, and failure. Minimizing part count means:

• Decreased material costs
• Fewer components to source and inventory
• Reduced quality control steps
• Minimal assembly times
• Less opportunity for defects or errors

At StudioRed, we always challenge ourselves to look for opportunities to combine multiple functions into single parts or eliminate unnecessary components. For example, instead of using separate fasteners, can we design snap fits or living hinges that are integrated into the parts themselves?

Of course, there’s a balance to strike. Overly complex multi-function parts can sometimes be more difficult or expensive to manufacture than multiple simple parts. But in general, a thoughtful reduction in part count pays dividends in manufacturing efficiency.

2. Standardize Parts and Materials

Opt for off-the-shelf parts whenever possible to avoid reinventing the wheel with each new project. This streamlines your inventory management, cuts procurement costs, and ensures consistency in production. Reusing the same parts across multiple products also creates economies of scale. By avoiding custom-made components, you can eliminate the time and cost of tooling and setup.

We encourage our designers to start with standard parts and only move to custom solutions when absolutely necessary. It’s also valuable to develop internal standards for commonly used components across product lines.

For materials, we default to widely available options that our manufacturing partners are experienced in working with. Uncommon materials may sometimes be necessary but often introduce additional cost and complexity.

3. Use Modular Design

Modular design involves creating independent subassemblies or modules that can be easily put together to form the final product. Imagine your product as a LEGO creation — a collection of individual bricks that come together to form a cohesive whole.

By breaking down your product into smaller, self-contained modules, you create a flexible system where each module can be manufactured and tested independently. Just like LEGO bricks, these modules can then be easily assembled and disassembled, allowing for customization, streamlined repairs, and faster upgrades without scrapping the entire product.

4. Prioritize Ease of Fabrication

A core tenet of DFM is designing parts to be as easy to fabricate as possible using the available production processes. This may involve adding draft angles, adjusting wall thickness, or optimizing geometry for the specific manufacturing techniques you’ll use, such as injection molding, sheet metal stamping, CNC machining, or 3D printing.

Whenever possible, choose fabrication methods that align with the capabilities of your manufacturing partners. Avoid pushing the boundaries too far beyond industry norms, as this increases risk and cost. Instead, aim for a design that plays to the strengths of the factory.

For example, if a client only produces a hundred devices a year, they might prefer we use sheet metal parts rather than invest in an expensive injection molding tool. Conversely, for clients producing thousands of units annually, injection molding becomes more cost-effective and allows for more complex surface development.

5. Optimize Assembly

While this principle starts to blur the line between DFM and DFA, it’s a fundamental consideration to a future-proof design process. Assembly optimization includes:

• Designing parts that are easy to align and assemble from a single direction (ideally top-down)
• Using symmetrical parts to reduce orientation issues
• Incorporating self-locating features, such as tabs, slots, or grooves, to minimize handling
• Including self-fastening elements, such as snap fits or press fits, to eliminate the need for additional fasteners like screws or adhesives
• Minimizing the need for specialized tools to reduce tooling costs and improve production line flexibility

In a recent project for a self-checkout system, we asked the manufacturer for input during the design phase. During their review, they suggested several improvements, such as adding wire clips to manage cable routing. They also ran a mold flow analysis, which checks how plastic is injected to help prevent sink marks and warp. This feedback allowed us to update our files before investing in tooling, saving time and money.

6. Be Flexible With Tolerances and Specifications

While it may be tempting to specify extremely tight tolerances everywhere, this level of precision is often unnecessary and expensive to achieve consistently. Instead, be judicious in how you apply tolerances to the design. Allow looser fits where possible and only tighten up on critical interfaces. This reduces rework and scrap rates while keeping costs under control.

We perform a tolerance analysis to check that parts will fit together correctly, even accounting for the worst-case scenarios of manufacturing variations. For instance, we might run an analysis to ensure that a plastic part coming out of a mold with a tolerance of plus or minus a few thousandths of an inch will still fit properly with other components without gaps or interference.

DFM Best Practices

Through decades of experience at StudioRed, we’ve developed a set of best practices that ensure the successful implementation of DFM principles:

Involve Manufacturing Partners Early 

We often seek input from manufacturers before we even start designing. By involving them from the start, we can identify potential issues before they become costly problems. This collaboration helps us understand manufacturing constraints and gives us the opportunity to optimize designs for production.

Conduct DFM Reviews 

We hold regular DFM reviews throughout the design process. These reviews bring together designers, engineers, and manufacturing partners to evaluate the design from a manufacturability perspective.

Use DFM Simulation Tools

Modern CAD and simulation tools offer powerful capabilities for evaluating designs from a manufacturing perspective. At StudioRed, we regularly use tools for mold flow analysis, finite element analysis (FEA), and tolerance analysis.

Create Prototypes To Validate DFM Decisions 

While simulation tools are incredibly useful, there’s no substitute for physical prototypes when it comes to validating design decisions. We often create prototypes at various stages of the design process to test manufacturability, assembly processes, and overall product function.

Collaborate Closely With Suppliers 

Suppliers can and should be valuable partners in the DFM process. We tap into their expertise on things like material selection, part geometry, and assembly methods to inform our design decisions.

Real-World Examples of DFM

Let’s examine some real-world Design for Manufacturing examples from our work at StudioRed. These illustrate how DFM principles can lead to significant improvements in product design and manufacturing.

Cable Box

In a project for a national cable company, StudioRed was tasked with designing a set-top box. During a design review, the manufacturer suggested we flip the printed circuit board (PCB) upside down to enable “in-process testing.” This meant testing could be done on the manufacturing line without additional fixtures, significantly reducing costs.

The change required about 30 hours of CAD rework but saved significant time and resources in the long run. Had this DFM input been received later in the process, the redesign effort would have been much greater.

Sheet Metal Assembly 

In a sheet metal assembly project, StudioRed was faced with a decision on how to connect two parts to form a “T” shape. While screws, spot welding, or rivets were options, our partner, a major computer manufacturer, recommended something we hadn’t considered — a toggle lock. This simple change, incorporated directly into the metal stamping process, proved more cost-effective than other joining methods and eliminated the need for additional assembly steps or equipment.

By collaborating with the manufacturer and leveraging their expertise, we avoided the need for new files, drawings, and potentially even additional prototype and testing rounds.

Small Wearable Device 

A client approached StudioRed with the challenge of redesigning a wearable ring with embedded electronics. They had a very specific price point in mind and an ambitious production goal. Their existing ring design was expensive to manufacture and had a high failure rate due to tight tolerances and complex machining processes.

Recognizing the challenges of thin-walled, high-tolerance parts, we reached out to a partner specializing in hearing aid manufacturing. By collaborating with them, we were able to redesign the ring using two plastic parts plated in metal. This change improved the product’s reliability and consistency while reducing costs by over 90%.

By applying DFM principles from the very beginning, we were able to develop a superior design that could be produced at scale while exceeding the client’s target cost.

Streamline Your Product Development Process With DFM by StudioRed

Design for Manufacturing is about approaching product design with a deep understanding of manufacturing constraints and opportunities. At StudioRed, we’ve honed our DFM expertise through years of experience and a commitment to excellence. Our team of industrial designers and mechanical engineers collaborates closely with clients and trusted manufacturing partners to ensure every product we create is optimized for production from the very beginning.

Partner with StudioRed to transform your product development process. Contact us to learn how we can apply our DFM expertise to your next project.

FAQ

You might still have questions about how to implement Design for Manufacturability for your specific situation. Let’s address a few common ones that come up in our discussions with clients and partners.

How Long Does DFM Take?

The DFM process is iterative and never truly “done” until you launch the product. However, the upfront DFM work typically takes a few weeks to a few months, depending on the size and complexity of the project. It’s tempting to rush through it or skip steps to save time, but it’s always worth investing the time upfront to avoid much costlier delays and re-spins later.

How Do You Start the DFM Process?

The first step in DFM is assembling a cross-functional team with representation from design, engineering, manufacturing, quality, supply chain, and other relevant areas. Then, you need to establish the key requirements and constraints for the product, such as target cost, annual volumes, and required materials and processes. This will guide the design effort and DFM analysis.

Does DFM Only Apply to High-Volume Manufacturing?

While DFM is critical for mass production, where even small inefficiencies can snowball into major costs, it’s just as useful in low- or mid-volume runs. Even if you’re making 50 units instead of 50,000, DFM helps you avoid expensive surprises like overly complex assemblies, hard-to-source parts, or design features that require specialized tooling.

Where Can I Learn More About Specific DFM Applications for My Industry?

The best way to dive deeper into DFM for your industry is to look at real-world case studies and manufacturing guides tailored to your specific processes, whether that’s injection molding, CNC machining, sheet metal, or PCB assembly. Industry-specific resources like IPC standards (for electronics) or SPI guidelines (for plastics) are also good sources to turn to.

Better yet, talk to your manufacturer early in the design phase. Most offer design reviews or technical support that can flag red flags before they become expensive changes.