Design For Manufacturing – A Complete Guide

Developments in Design for manufacturing (DFM) have entirely revolutionized the world of manufacturing and production.

DFM plays a crucial role in determining the availability, quality and functionality of a product.

Let us consider a scenario in which designers develop an excellent design. Unfortunately, it is later determined during the manufacturing process that the design is very complex to manufacture, and it takes lots of additional costs and training for the operators to manufacture the product.

This is where DFM plays a critical role.

Once the product’s conceptual design is complete, DFM will help determine the practicality in manufacturing the product.

DFM helps to save unnecessary cost and the workforce required for the redesigning of the product. This will help to determine the best possible method of manufacturing by using the existing techniques and processes.

What is design for manufacturing?

DFA or DFMA is a vital part of product development. It is the process of ensuring that a design can be consistently manufactured with minimal defects by using a designated supply chain.

If the DFM is not implemented early, it might result in an excess production cost due to multiple design iterations.

Thus it is essential to implement the DFM as early as possible. The proactive implementation of DFM in the manufacturing process will help cut down the production cost substantially.

Why is DFM important?

Here are some of the critical reason why DFM is an important aspect of production:

1. Reduced cost of production  

It is a surprising fact that more than 70% of the cost of manufacturing is from various design decisions of manufacturing methods, and the remaining 30% is for production design like tool selection, process planning etc.

Giving importance to design optimization can significantly save the production cost.

One of the significant reasons why DFM is essential is that it helps to eliminate cost overruns. DFM brings better value to construction projects and ensures completion within the estimated time.

In today’s world, delay in completing projects results in severe losses to companies-loss in revenue regeneration, return of investment, legal hassles etc.

Implementing DFA will help to ensure that the construction is completed within the required time.

2. Ensure the practicality in production

Once the computer models are finalized, DFM is used to validate the design concept. Unlike the computer simulation, the actual product in the design environment is created to validate its practicality.

Computer models can often not be practically put into manufacture as there are various challenges involved when it comes to producing a model. There were cases in which engineers have to redesign the product as it is impossible to make it in the first place.

The prime goal of DFM is to ensure that the product is easy to manufacture. This is a critical step for the process development and design of the product.

3. It can impact your timeline

Once the software design is finalized, DFM can take a few weeks, depending on the complexity and functionality of the product.

Sometimes the entire process can go back and forth to ensure the optimal manufacturing method. It is advised to ensure that every aspect of the design should be confirmed and verified by a product designer to eliminate lots of mistakes that might creep in during the production process.

It might feel time-consuming, but in the long run, it is worthwhile.

4. Safety and Reliability

Unlike conventional manufacturing methods, adopting prefabricated components is much safer and reliable to use than traditional methods.

The product will have better quality since all the components will be manufactured and assembled later. This makes sure that the product will be of superior quality and long lasting.

Components that are produced in the factory and not based on manual skill sets combined with technology helps to ensure products with higher reliability.

5. Controlled onsite assembly

Since the fabricated elements are manufactured in a factory, there is a minimal dependency on weather conditions, site labour or other site based constraints.

DFM allows the manufacture of prefabricated structures, ensuring a simple execution of the on site project. 

How to perform DFM?

The following are the principal goals of running a DFM process:

1. Simplify the design process and reduce the number of parts to assemble

For a smooth and streamlined design process, it is essential to ensure that the number of parts to be assembled should be minimal. 

Once the computer modelling is complete, the production engineers have to evaluate carefully the number of components required for the particular design.

Important questions to consider include:

• Can this part be somehow combined with any other part?
• If combined, will it be possible for assembling and disassembling
• Can the pieces be produced without using specialized equipment?
• How does the part in question move in relation to other moving parts?
• Will combining with a different part affect the manufacture.

2. Parts should be designed to ensure a smooth fabrication

While designing the parts for manufacturing, the designer should keep in mind the following guidelines:

• Carefully review the design and eliminate those parts that will result in expensive tooling, additional efforts, unnecessary features and complicated process.
• Try to make use of commonly used materials that are compatible with the existing production process. Using a new material or process might be time-consuming and results in wastage of money and workforce. 
• The design should be reviewed with experts of various departments such as engineering, metallurgy, production, quality control and fabrication. This will help ensure that the existing tools and machine can be used to the maximum possible extent and eliminate the need for unnecessary expenses. The meets also help to keep the members of the organization updated on recent developments.

3. Design should allow ease of assembly

Over the years, several methods have been developed to allow ease of mechanical assembly. Engineers should first consider when and where the assembly process will take place. Assembling the product in the field will be different from assembling it in a work line.

Here are some of the essential tips to ensure ease of assembly: 

• Assembly parts should have chamfers and lead-in features for making it easy to insert bolts and pins.
• Product design should be designed to be assembled from the top up by using gravity.
• Avoid any unnecessary orientation in the assembly process to avoid the wastage of time.
• The assembly should be done with simple patterns. In case it is difficult, it should be divided into sub-assemblies.
• Make sure that the technician can see what they are assembling by providing adequate tool clearance.
• Put restrictions on the type and size of hardware that can be used in a specific assembly unit. This will help to avoid any incorrect hardware being used in one particular assembly unit.

4. Reduce the number of flexible parts

While designing the components, engineers should consider the usage and type of environment where the product will be used.

Products often fail if the components are not well suited to operate in the desired working environment.

• The connectors should be strong and not flexible.
• Avoid flimsy and flexible cables.
• Utilize direct drive instead of the belt.
• Make sure to use the attachment of connectors as error proof by using unique ones that cannot be fitted in the wrong way.

5. Use effective fastening techniques

Engineers should ensure that the fastening elements are robust, long lasting and easy to attach. If it is felt that some joints are time-consuming, alternate means should be sought to connect.

• Reduce the types of hardware required for assembling
• Use integrated connections such as snap-fit.
• Try to make use of bonding adhesives for attaching
• It should be easy to remove the attachments for the repair of servicing

6. Modular product design

Within the manufacturing industry these days, modular designs have become a popular method for manufacture.

This is beneficial in several different ways. These include: 

• Allows to achieve production balance all through the year.
• It helps to reduce the learning curve of employees and reduce the time for giving training for assembly.
• Improvement can be given to a specific part without having much effect on the entire product.
• It helps to cut down the cost by minimizing the number of parts within one family.
• Customizations can be quickly done.
• Improve the maintenance and servicing of the products.
• It helps to instal the product within a short period, helping to save money and human resources.

7. Design for automation

Here are some of the key benefits of designing the products for automation. A few of them are:

• Steady output
• Enhanced efficiency
• Helps to cut down labour costs
• Improved quality 

Automated production offers less flexibility in design when compared to the manual process. The product must be designed in a way that it can be handled effectively by various automatic activities such as

• Handing by the robotic arm
• Magnetic lifting
• Automated placements

8. Design by using the known process and existing techniques

• Rather than implementing newer producing techniques and lesser-known processes, it will be wholly beneficial if the designers can make use of the existing ones.
• Before finalizing a design, the production engineers should be fully aware of the equipment required for handling and the process capabilities.
• Try to avoid tolerance beyond the capacity of the manufacturing process. Before the onset of production, evaluate carefully whether the project in hand requires advanced production techniques.
• Make sure to check the interaction between different components to avoid tolerance stack up issues.
• Use finish callouts only when it is required and avoid one sided tolerances.

9. Make sure to use Commonly used materials and parts

During the design process, make sure to use commonly used parts and materials. This will help to reduce the cost of production and minimize the inventory levels.

Besides, this will also help minimize the worker’s team’s need to learn new manufacturing methods.

Commonly used materials include the parts that are already in use or similar products or assemblies.

10. Mistake proof product design

While designing, it is essential to make sure to prove the designs. Adding too many slots and tabs, interference features, and asymmetrical holes can make it very difficult to assemble the product.

Ensure that the parts can be appropriately assembled without the need for any special adjustments or alignments during the assembly process.

Designers should also ensure to specify any features or quality dimensions to test the product for quality. 

11. Equipment Handling 

This is a step that is often neglected during the production process. Faulty equipment handling can result in severe consequences to the operator’s safety and the equipment.

• To make the fabrication easy, the design parts should be symmetrical along both axes.
• Parts should be designed so that the technician can easily understand and orient them for welding or joining. For automated assembly, the design should allow the robotic arm to pick up the part quickly.
• The drawing should be made in such a way as to indicate the proper origin when fed into a process.
• Try to avoid large parts as it requires heavy lifting equipment and increases the risk of workers injury.
• Avoid parts with sharp edges to minimize any chance of injuring the operator.
• Make sure to avoid parts that get entangled in the container, as it will be hard for the operator to handle the part. This can consume unnecessary time and effort.
• Try to minimize the distance to access and move the part to the assembly unit. It is advisable to keep the components at least two steps from the assembly unit.

12. Orientation and handling

The engineers should determine how the parts are going to be oriented and handled. If this is not determined and fixed beforehand, it will result in unnecessary movement of the parts, risking both the equipment and the operator’s life.

Benefits of Design for Manufacturing

Here are some of the benefits of DFM:

1. Reduce New Product Introduction Cycle 

Design engineers are constantly on the lookout for production methods that help create products that are robust and keep up the design standards.

Using DFM, it is possible to identify the manufacturing issues that might creep in. This will help to prevent any design or production changes required to address the issue.

It has been noted that sometimes the design may be challenging to assemble on the manufacturer. This will add additional cost and time to the initial development and affect the production of the product.

Aided by DFM, it is possible to reduce the number of parts and operations required for manufacturing.

2. Helps to ensure a better quality output

One of the essential ingredients for better quality output is standardization. Standard parts and operations are time tested by including them in a lot of devices.

Implementing DFM makes it possible to evaluate the existing manufacturing process and design to implement a standard operating procedure.

This is beneficial since the technicians are already well-versed in the regular operating procedures ensuring higher quality output.

It is also possible to design the product with tolerances within the plant’s existing capability.

3. Minimize the overall production cost 

By implementing DFM, it is possible to bring the development and production team under one roof. It will be practical to discuss the availability and cost of certain raw materials critical for the new product.

If the raw materials are scarcely available, the production team can discuss with the procurement team to have a better alternative for the product.

DFM is effective in identifying substitute solutions that are effective when it comes to product handling or operations. 

By using the concept of modular design, it is possible to optimize the inventory and material control, thereby minimizing the assembly time to the maximum possible end.

This will also help to ensure a shorter turnaround time for mass production.

How long will DFM take?

The DFM can take a few days to a couple of weeks, depending on the:

• Type of the product
• Parts to be manufactured
• The complexity of the product
• Type of manufacturing process

On average, the DFM will take around two weeks to complete. For more complex designs, it will take about three to four as well.

Examples of DFM

DFM can be used in casting to reduce casting defects. This will help to optimize the geometry and shape of the product, thereby reducing the shortcomings.

Recently DFM helped to reduce the different parts required to manufacture a tank for the American military. The number of components to be assembled was decreased from 24 to 8.

The components with joints can be manufactured using snaps fits, an effective form of fastening the two parts together. This will help to minimize the unnecessary production cost and time taken for manufacture.

Bottom Line

Design for manufacturing has completely revolutionized the world of manufacturing. With DFM, it is possible to manufacture products with the most complex designs within a short time frame.

DFM has brought practicality in the manufacturing sector where it is possible to determine the manufacturing possibility while it is still in the design phase.

This will also help avoid any last minute design changes that have a massive impact on the engineering and the cost of production.

In this article, we have mentioned some of the significant advantages of using DFM for manufacturing.

Thus, in summary, DFM will help to:

• Speeding up the production process.
• Minimizing the time taken for product development.
• Cut down unnecessary cost due to frequent design changes.
• Quicker time to market.
• Identify the possible design flaws.
• Identify what all parts can be coming to reduce the design steps.
• Produce superior quality products
• Create a safer production environment.

Reach out to EKO industries for a specialised end to end services on DFM.