As product designers and manufacturers, we are always looking for ways to make the manufacturing process faster, easier and more cost-effective. This is where DfM comes into play.
Design for Manufacturing (DFM) is one of the most critical aspects of product development. It is the important link between conceptual design and manufacturing and can have a huge impact on the performance and cost of a product.
This article addresses a frequently asked question: What is DFM? To provide a comprehensive answer, we will delve into design principles for manufacturing and DFM analysis. Additionally, we'll highlight some basic skills you should have as a DFM professional and hope to provide tips for implementing these skills into your product development cycle.
What is DFM (Design for Manufacturing)?
Design for Manufacturing (DFM, as it is often abbreviated) is a fundamental engineering concept that encompasses all activities aimed at transforming an idea into a practical, usable product. Going from prototype to production requires technical analysis, financial management and in-depth knowledge of the market.
We will discuss the various aspects in a moment, but the basic definition is exactly the same as above.
In most cases, product development starts with a vague idea without practical limitations. Due to various reasons such as high cost, design complexity, unavailability of materials, etc., manufacturing may be impossible. DFM analysis looks at product development from these perspectives, lending credibility to product designers' ideas and investors' investments.
Main objectives of the DFM
Design for Manufacturability is a comprehensive method that branches into multiple areas of the product development cycle. Therefore, it is important to understand the main objectives to provide DFM engineers with a clear structure for their work.
This section examines the main objectives of DFM analysis from a business perspective.
Cost
As with any project, the main concern is the financial impact. The main objective of Design for Manufacturing is to minimize the production cost of a project as much as possible. This includes costs such as raw materials, manufacturing, energy and labor.
DFM ensures the financial viability of the product development process and guarantees a healthy return on investment.
Quality
Another goal of design for manufacturing is to maximize product quality. Of course, this is within constraints such as budget, material options and target markets.
Higher quality products are more attractive to consumers, strengthen the brand image and generally lead to better product performance in the market. Consequently, this also opens up new opportunities for market expansion and business growth.
sustainability
Minimizing waste is a top priority for DFM engineers. A key element of DFM analysis is identifying all areas where waste is generated and optimizing the process to eliminate as much waste as possible.
This objective aims to ensure that production meets modern sustainability goals arising from environmental concerns and the overconsumption of limited resources. Furthermore, it is also another way to minimize costs.
Design Principles for Manufacturing
Now that we have a comprehensive overview of design for manufacturing, let's dive into the details from a technical perspective.
Keeping in mind the key goals of reducing costs, improving quality, and sustainably reducing waste, engineers use DFM analysis to try to improve the following five areas of a manufacturing process.
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The process includes all physical manufacturing operations. Companies use a variety of manufacturing processes such as CNC machining, injection molding, 3D printing, electrical discharge machining, etc.
The job of production optimization experts is to find ways to optimize these processes. First, they review the design and verify that the designers made the correct process selection.
For example, an electronic box can be manufactured using several techniques, including machining, injection molding and 3D printing. DFM experts evaluate the pros and cons of each process in terms of design and suggest the most practical process for design and production teams.
Additionally, there are multiple process parameters within each manufacturing technique. For example, in CNC machining there are parameters such as cutting speed, feed and depth of cut that can be optimally adjusted to achieve high productivity and quality. DFM analysis aims to find a suitable machining strategy.
project
Design optimization is one of the most important principles in project production. Due to the loose nature of product design during the idea development phase, there are always some unaddressed aspects of the design, from a manufacturability perspective, that need to be addressed before the design can go into production.
In DFM analysis, engineers identify all these problems and develop solutions for them. In most cases, this is limited to small design changes here and there. For example, in DFM for CNC machining, suggestions might include adding fillets at sharp inside corners (see image below) to adjust the radius of the cutting tool.
In rare cases, major design changes may be proposed to the design team, which requires both teams to work together to find the best solution. This can happen when DFM teams use methods like topology optimization to suggest weight reduction or a change in preferred manufacturing technique.
Technical design is an iterative process and it is expected that there will be some deviations between design and production.
materials
Another area that production planning examines is materials. A wide variety of materials are available for manufacturing products, which provides a great opportunity to optimize material selection.
Let's go back to our example case. Enclosures can be made from metal, plastic, polymers, and even composite materials. However, only one of them is the most suitable choice. DFM analysis compares each material with the functional requirements of the product and suggests the best one.
For example, if the case is intended for cheap electronics, a simple plastic case will suffice. Choosing an expensive and difficult-to-manufacture metal would involve excessive engineering effort. When an expensive, high-value product needs to be protected against impact loads, composite materials may be the right choice.
Furthermore, the selection of materials involves much more than just the functionality of the parts. DFM engineers must also consider material availability and cost. Additionally, some materials have a negative impact on the environment and may contribute to missing carbon footprint targets.
Environment
The product's working environment plays an important role in the DFM process. The environment consists of characteristics such as mechanical stresses (static and dynamic), temperature, humidity, chemical stress, and electrical/magnetic disturbances.
The conceptual design will not always be able to withstand such environmental conditions. Therefore, DFM engineers apply manufacturing design principles to solve such problems.
Solutions may include dimensional changes, such as increasing wall thickness to accommodate mechanical loads. You may suggest another material due to its better thermal stability. In other cases, a special surface coating may be added to the manufacturing process to protect the part from chemical exposure.
Requirements Testing
Most products are subject to certain legal requirements and standards. These standards can be industrial, internal or even governmental. Design optimization engineers ensure that part design and manufacturing processes meet these standards.
How does Design for Manufacturing try to achieve its goals?
From the above discussion, it is clear that Design for Manufacturing is a very goal-oriented approach and encompasses multiple objectives. Achieving all of these while balancing them with project constraints is a complex problem.
Below are some of the practical methods DFM professionals pursue to achieve their goals.
Minimize the number of parts
The number of components in a mechanical assembly can be minimized to simplify, reduce costs and reduce waste. Although not always possible, DFM analysis always focuses on identifying and eliminating redundant parts through careful analysis.
Use standardized pieces
Designing for manufacturability also involves using as many standardized parts as possible. Standardized components may include fasteners (nuts, bolts), sealing devices (O-rings, gaskets) and movement mechanisms (lead screws), all readily available directly from stock.
This reduces production effort, focuses manufacturing effort on non-standard parts and reduces costs.
Modular design
Using modular designs is another technique commonly used by DFM engineers. A modular design means that the product assembly is divided into different subassemblies (modules) that can be easily changed without affecting the design of other modules.
This approach makes it much easier to perform product updates during the prototype development phase. Additionally, the entire design process is placed in a more systematic structure, where designers can conveniently select specific modules to work on without worrying about overall functionality.
Easy construction
Finally, a critical design objective for manufacturability is to make product assembly as simple and quick as possible. The project must be considered from an assembly/disassembly perspective and DFM engineers ensure that the effort required for these activities is minimal, saving time and money.
What does it take to become a DFM specialist?
This article discusses various aspects of design for manufacturing and places great emphasis on the role of DFM analysis professionals in achieving objectives.
This section briefly introduces our readers to some of the key skills they can learn to become DFM professionals.
Advanced simulation and modeling
CAD modeling and simulation software are commonly used in DFM analysis. They allow engineers to determine whether the design will withstand environmental conditions and are useful in modifying the design according to manufacturing requirements.
Collaborative design
Design for Manufacturing is a collaboration between designers, product developers and manufacturing experts. Modern businesses encourage this teamwork through on-site and online collaborative design activities, which include learning to use tools like cloud-based technologies and whiteboards.
Design suitable for production vs. design suitable for assembly
For engineers in this area, the distinction between design for manufacturing and design for assembly is important. Although the differences are subtle, it is good to be aware of them as these two techniques vary greatly in detail.
Let's briefly look at some of the main differences between them.
Parts vs. assemblies : As the name suggests, design-for-assembly analysis deals with multiple components in a mechanical assembly, while design-for-manufacturing analysis focuses specifically on a single part.
Project vs. assembly : DFM analysis is more focused on design optimization and material selection. Design for Assembly, on the other hand, places more emphasis on simplifying the assembly process through the use of efficient assembly techniques.
DFM applications and examples for various manufacturing processes
There are numerous examples of manufacturing design in industrial settings that can help us develop a better understanding of how it works in a practical setting. This section covers some of them to give you an idea of how manufacturing projects can be implemented in practice.
1. CNC Machining
CNC machining is one of the most common manufacturing techniques for DFM analysis. There are different ways to achieve design-for-manufacturing goals. The most important are the following:
- Sharp internal corners : Designers make this common mistake when designing internal slot/pocket features. The inner corners must be rounded to accommodate the rounded geometry of the cutting tools.
- wall thickness : Some wall/floor elements are often too thin to withstand shear loads. This can lead to parts breaking during machining. Therefore, DFM engineers recommend thicker walls/floors when given such geometries.
- Pocket Depth : Pocket milling is a true test of tool rigidity. The deeper the pocket becomes, the more violently the cutting tool vibrates, resulting in poor surface finish and tool failure. Therefore, DFM analysis often leads to changes in the geometry of very deep pockets.
- Tolerance : It is common for design tolerances to change during DFM. Because meeting tolerances is expensive, DFM professionals often relax non-critical tolerances to save time and money.
2. 3D printing
3D printing is another area that requires attention from DFM engineers before designs go into production.
- Supports : Certain protruding elements in 3D printing designs are very weak and tend to fall due to gravity during the printing process. A common DFM solution to this problem is to use scaffolding beneath these elements. The operator later removes these scaffolds.
- wall thickness : This problem is similar to thin walls in CNC machining. Very thin walls often cannot be printed because they are very fragile and can break during printing. Therefore, the design for manufacturing suggests thicker walls in some designs.
3. Injection molding
Finally, we will discuss the applications of Design for Manufacturing in the context of injection molding.
- Undercuts : Many injection molded designs feature undercuts. Sometimes these are not viable as they make tool movement difficult, or there are cheaper alternatives to achieve similar geometries. DFM experts are responsible for pointing this out and suggesting viable solutions.
- Draft Angles : Desmolding is an important part of the injection molding process. It must be done smoothly and quickly and not damage the part or die. To maximize efficiency, engineers often add a small design to the design during DFM analysis to facilitate demolding.
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DFM is where all stakeholders involved in product development come together and solve problems directly related to product design, processes and the manufacturing process. This ensures a smooth product transition from design to assembly and mass production.
Concluding
This concludes our discussion on the topic of Design for Manufacturing. It is a very comprehensive technical analysis with a variety of main objectives, tools and applications. In the era of rapid prototyping, it has become an indispensable tool for evaluating the manufacturability of product designs.
Common questions
Who is responsible for the DFM?
In a manufacturing company, DFM engineers are responsible for DFM analysis. You will work with the design and production teams to bridge the gap between conceptual design and manufacturing.
How long does DFM last?
A DFM project can take an average of 1 to 5 days to complete. Depending on the complexity of the project and the DFM analysis, the duration may be longer or shorter.
When should DFM be implemented in the product development process?
DFM must be implemented in parallel with the design process. Once the conceptual design takes some form, a preliminary analysis must be carried out to assess its basic feasibility. As design iterations progress, the DFM team must provide input until conducting a final, in-depth DFM study of the final design before moving into production.
