What design for manufacturability (DFM) is and why it matters

Developing a part involves many steps and moving pieces, in both a planning and manufacturing sense. Preparation becomes vital to the part development process, as it sets the stage for project success. This preparation lays the groundwork for designing for manufacturability (DFM).

What is design for manufacturability?

Design for manufacturability (DFM) is the systematic process of engineering products for optimal manufacturing efficiency, cost and quality. In plastic injection molding, DFM is more critical than ever—industry timelines are tighter, assembly is more complex and customers demand speed to market without sacrificing quality or cost.

As a multidisciplinary effort, DFM leverages advanced simulation, material science, metrology, prototyping and automation to streamline part development through smarter, earlier engineering decisions. Selecting a partner with a deep bench of experience provides significant expertise and practical know-how to best leverage key tools and industry best practices during this process. With up to 80% of a part’s cost determined during the design phase, technical rigor in DFM is essential for competitive success.

Why does design for manufacturability matter?

DFM is not just a technical requirement—it’s a strategic advantage. The design planning stage is the most opportune time in the development process to consider how the end user wants the product to function. A better understanding of how it will be used allows for a more robust design, provides an advantage to realize higher quality parts and ensures efficiency.

In manufacturing, early design decisions directly impact:

• Product cost: When the combination of the material selection, tooling complexity and process efficiency are locked in early, it often determines 70–80% of the final product cost.
• Quality assurance: Robust designs minimize defects, enable statistical process control and ensure repeatability. Scientific injection molding and process monitoring are planned from the outset.
• Production efficiency: Upfront investment in simulation allows for the effective mitigation of factors that could impact uptime, scrap rates and tooling longevity long before the project hits the floor.
• Speed to market: Decades of subject matter expertise coupled with simulation, prototyping capabilities and robust project planning allow for a more predictable and streamlined product launch.

How DFM injection molding manufacturers ensure a quality product

To ensure designs meet quality and reliability standards, the DFM process includes several checkpoints that assess technical impacts to a part, identifying risks and validating robustness before production begins.

One example of a checkpoint in the DFM process is Process Failure Mode Effect Analysis (PFMEA), a structured method for calculating the likelihood of a product failure, where it might occur and its level of severity. PFMEA takes place after the initial design is complete, allowing mold makers and manufacturers to view the design through the customers’ eyes and identify potential pitfalls in making the part.

Another critical checkpoint is the Advanced Product Quality Planning (APQP) process, which focuses on ensuring design robustness. APQP helps mold makers and manufacturers better understand customer needs, provide feedback and confirm that the design aligns with process capabilities. When combined with PFMEA, APQP strengthens failure mode mitigation and establishes verification and validation standards.

What are the six core technical principles of design for manufacturability?

1. Early supplier and customer involvement »

Early customer involvement is vital to help ensure a flawless part. The DFM process begins with cross-functional collaboration internally and with the customer. Engineering, tooling, quality, automation, purchasing and plant personnel are engaged from day one. The customer provides insight into how the end user will need the product to function and can better help determine how specific features will play a role in its functionality. Additionally, the customer will provide context around the environment the final part will live in and help anticipate any variables that may inhibit proper functionality. This important conversation ensures:

• Holistic design reviews: All disciplines contribute, identifying risks and opportunities across the product lifecycle.
• Supplier expertise: Material vendors and component suppliers are consulted early, leveraging their technical knowledge for optimal selection and manufacturability.

 

2. Advanced material selection »

Material selection takes place at the start of the plastic part design process and is critical because it directly impacts part performance, manufacturability and overall cost efficiency of a finished part. Material choice begins with understanding how the part will perform in real-world conditions. This includes evaluating mechanical properties such as tensile strength, impact resistance and flexibility to ensure the part can withstand its intended load and stress. Chemical resistance is important for applications exposed to oils, solvents or harsh cleaning agents, while environmental durability, such as UV stability for outdoor use or resistance to extreme temperatures, helps guarantee long-term reliability.

Even the best-performing material must be compatible with the molding process, making it imperative to understand the processability of the material for the part. Factors like melt viscosity determine how easily the resin fills complex cavities, while shrinkage rates affect dimensional accuracy and tolerance control. Additionally, compatibility with automation, including robotic handling or insert molding, can influence cycle times and overall production efficiency.

For some injection molding manufacturers, considerations surrounding environmental impact must be taken into account. This includes choosing recyclable resins or incorporating regrind strategies to reduce waste without compromising quality. Lifecycle analysis also plays a role, helping manufacturers understand the environmental footprint from raw material sourcing through end-of-life disposal, aligning with sustainability goals and regulatory requirements.

 

3. Tolerance optimization and metrology »

Metrology is a vital step in the DFM process, establishing reliable and repeatable measurements. During this stage, the feasibility of each tolerance and dimension is reviewed, with the goal of ensuring the long-term statistical capability of critical and major dimensions. A comprehensive approach is necessary to ensure dimensional accuracy and process stability throughout manufacturing. It begins with geometric dimensioning and tolerancing (GD&T) review, where a team carefully reviews all critical dimensions and challenges unnecessary callouts that could increase cost and complexity. Overuse of GD&T often results in impractical or even “illegal” tolerances, which add inspection burden and costs without improving quality. This is something EVCO actively works to prevent during the DFM process.

To maintain flexibility, critical dimensions are fabricated in a safe condition, allowing for post-mold adjustments when needed. This proactive planning ensures that any refinements can be made efficiently without compromising part integrity. Methods of measurement are identified for suitable reliability and repeatability to support validation and production of each product. Based on the outcome of the quality assurance planning activity, critical steel dimensions will be fabricated in steel-safe conditions to allow for minor adjustments and molded part capability.

Finally, understanding statistical capability requires incorporating long-term capability studies into the workflow, such as Ppk and Cpk, for major dimensions. These studies provide insight into process stability over time, reinforcing confidence in consistent quality and performance.

 

4. Smart part geometry and tooling-aware design »

EVCO’s approach to smart part geometry and tooling-aware design combines advanced simulation, innovative cooling strategies and automation-ready engineering. It starts with mold flow analysis, leveraging high-end, in-house simulation tools to predict fill patterns, cooling rates and potential defects such as weld lines or sink marks. This proactive analysis helps identify and resolve issues before production begins, ensuring optimal part performance.

To further enhance efficiency, EVCO can incorporate conformal cooling through 3D-printed metal inserts. These inserts enable precisely engineered cooling channels that significantly reduce cycle times while improving part quality. This technology accelerates production while supporting consistent dimensional accuracy.

Design considerations for downstream integrated operations including automation and secondary operations are reviewed for product preservation, labor reduction and efficiency. Automation requirements are integrated early in the process, allowing for seamless downstream handling and reducing labor-intensive steps.

 

5. Scientific injection molding and process monitoring »

EVCO’s process control strategy is built on three pillars: development, monitoring and risk mitigation. It begins with process development, where injection parameters such as pressure, temperature and speed are carefully validated to establish robust processing windows. This ensures consistency and repeatability from the very start.

To maintain precision during production, EVCO employs real-time monitoring through advanced sensors and controls. These systems continuously track critical process variables, enabling immediate corrective action whenever deviations occur. This proactive approach minimizes variability and safeguards part quality.

 

6. Sustainability engineering »

Integrating sustainability engineering into every stage of the DFM process is an aspect that many injection molding manufacturers are now requesting. Designs are carefully optimized to minimize resin usage without sacrificing performance, ensuring material efficiency from the start. Beyond production, lifecycle analyses evaluate recyclability, end-of-life options and overall environmental impact, helping customers meet sustainability goals. For high-volume applications, hot runner systems are often selected to eliminate waste and improve efficiency, reinforcing commitment to both cost-effectiveness and environmental responsibility.

How DFM helped increase efficiency and create higher quality medical disposables

For decades, a global medical technology company used the same supplier to mold medical disposables used in physicians’ offices, which require high standards of quality, efficiency and traceability. In reviewing the incumbent’s manufacturing processes, several details stood out:

• A 72-cavity mold limited output and efficiency.
• The bulk production had parts falling into large bins, followed by offline packaging.
• There were quality control challenges, including defects like “flash” that could potentially cause patient discomfort.
• Decoupled molding and packaging offered limited traceability.

With increasing demand and the need for improved quality and efficiency, the company sought a new partner capable of innovating the existing manufacturing process.

The DFM process allowed EVCO to improve plastic part design and production

EVCO collaborated closely with the company’s tenured engineers, incorporating their feedback and quality requirements into the design and manufacturing process. As a result, EVCO delivered a fully integrated, high-speed manufacturing and packaging system with process improvements in three core zones:

 

Engineering and simulation increased output »

• Advanced mold design: EVCO engineered a new mold with increase cavitation, significantly increasing output.
• Simulation: Extensive simulation work ensured the mold could operate at unprecedented speeds (96 parts every 5 seconds) while maintaining part integrity and dimensional capability
• Physics optimization: The engineering team balanced cooling rates and material flow, right-sizing runner channels to meet the company’s regrind allowance.

 

Integrated automation ensured quality and efficient packaging »

• High-speed robotics: A side-entry robot immediately packages parts into sleeves and then into bags, maintaining cavity separation for traceability.
• Vision inspection: Every 50 seconds an online vision system inspects a part from every cavity, allowing for the quick detection and isolation of defects if they are to occur.
• Automated packaging: The system stacks and seals sleeves, ensuring zero downtime and efficient throughput.

 

New process increased sustainability »

• Closed-loop regrind: All runner scrap is reprocessed and reused within the allowed limits, a notable achievement for medical products.

EVCO’s innovative approach enabled the company to achieve new levels of efficiency and quality. This project stands as a testament to the value of collaboration, engineering excellence and process optimization in medical device manufacturing.

EVCO’s technical advantages

EVCO Plastics transforms DFM from a routine step into a strategic advantage. By integrating proven methodologies like PFMEA and APQP with advanced engineering tools and collaborative expertise, EVCO ensures every design is optimized for performance, cost and sustainability before production begins. Here’s what sets EVCO apart:

• In-house mold flow simulation: High-end software and dedicated specialists deliver rapid, accurate analysis of fill patterns, cooling rates and potential defects, eliminating guesswork and reducing risk early in the design phase.
• Cross-functional teams: Experts in processing, tooling, quality, automation and purchasing collaborate from the start, ensuring every design decision supports efficiency, manufacturability and long-term reliability.
• ISO-certified quality systems: Rigorous standards and global best practices guarantee consistency, compliance and repeatability across all projects.
• Advanced metrology and tooling: Built on a mastery of GD&T and print interpretation, EVCO is equipped to drive out non-value-added inspection costs, effectively plan tool designs for conformance and streamline gage qualification and validation.
• Material expertise and sustainability: EVCO leverages deep knowledge of resin behavior, material properties and lifecycle analysis to minimize environmental impact while meeting performance requirements. Closed-loop regrind strategies and recyclable resin options further support sustainability goals.
• Rapid iteration and responsiveness: Early design feedback and simulation cycles shorten time-to-market without compromising quality or functionality.
• Industry 4.0 integration: Smart manufacturing tools and real-time data analytics ensure precision, adaptability, traceability and scalability for global programs throughout production.
• Customer education and partnership: Through lunch and learns, technical training and collaborative design reviews, EVCO empowers customers to make informed decisions and turn design challenges into competitive advantages.