One method for determining minimum part quantities is to first list out all the components in your assembly, including hardware. Then ask the following questions:. Through reduction of component part quantities you also reduce the amount of hardware and the number of assembly steps required.
The likelihood of assembly errors are subsequently reduced in relation to the reduction in assembly steps. The designer should consider the method of fabrication that may be used for producing the parts, the required material specifications and required production volumes. Some particular guidelines to review are as follows:. The designer should become familiar with the process capabilities of any equipment required for the manufacture of the part. Avoid tight tolerances beyond the proven capability of the manufacturing processes.
Determine if improved process capabilities are required early in the design or program schedule to allow time for any process improvement activities and the establishment of proper process controls. Parts should be dimensioned in the center of the tolerance range to allow for the greatest variance and still remain a functional conforming part.
In addition, avoid one sided tolerances and use surface finish callouts only when required, as that may result in unneeded additional part cost. Chamfered or radius corners should both be allowed if it will not change the function of the part.
This will permit production control to route the part to different machines based upon demand. Whenever possible the design should incorporate common parts and materials, including parts already in use in other similar products or assemblies.
Common parts and materials help minimize inventory levels and will result in lower cost and higher quality. The new content of the design was greatly reduced therefore the design risk was reduced.
In addition, the learning curve of the assembly team members was reduced. Designers should look for ways to mistake proof their designs, making the proper assembly of mating parts instantly recognizable and impossible to assemble incorrectly. By the addition of tabs and slots, asymmetrical holes and interference features the parts can be made difficult or impossible to assemble in reverse or oriented improperly.
The designer should also avoid the need for any special adjustments or alignments in the assembly process. With enough thought put into the design of an assembly many of the parts can be made mistake proof.
The designer should also consider how the part or assembly could be inspected for quality purposes. In other cases the parts may need to be measured and the designer should indicate any key or critical to quality dimensions or features. The design engineer should consider how the parts are going to be handled and oriented during the manufacturing and assembly processes. If this is not done, the impact could range from non-value added motion and part movement to possible operator safety issues or requirements for special fixtures or lifting devices.
There are several basic principles that can be applied to improve parts handling and orientation. A few examples can be found below:. There are many methods to design for ease of assembly.
When designing for assembly, remember the simpler the design the easier it is to assemble. The designer should consider where the assembly is going to be performed and the tools or equipment that will be available. For example, if the product is sold as a kit and assembled in the field by the customer, it is different than if it will be assembled on an assembly line or in a work cell. There are many guidelines for ease of assembly.
The following list contains some examples:. The designer must consider the usage and environment in which the product will operate. Many product failures are due to the component parts not being robust to the application. There was a display system that operated a piece of equipment used outdoors which has inherent vibration during operation and experiences heavy usage.
The displays were failing due to a fragile ribbon cable that became brittle over time and would break. It was also found that the cable connectors did not lock into place and would sometimes vibrate out, breaking the connection. The product was redesigned to include a locking connector attached to a temperature resistant cable robust to the operating environment.
Here are a few ideas to think about:. Threaded bolts, washers and nuts are time consuming to assemble. If they are required, consider weld nuts or nuts that are captured in the part. The designer must look at alternative methods of attachment.
Modular design is becoming more prevalent in many industries. It has various advantages for the manufacturer, the dealer and the customers. Some of the advantages to modular design are listed below:. There are many obvious advantages to designing products or parts for automation.
A few of them are listed below:. Something else to consider is the fact that automated production can require less flexibility in design than manual production. The product must be designed so that it can be handled with automated equipment like gripping or magnetic lifting and placement equipment. You must also use self-locating parts, simple parts-presentation devices and avoid the need for clamping or securing parts during assembly or processing.
The primary goal is to design a product and process to be as efficient as possible. Whether a product is assembled by machines or by operators, the designer and the mechanical engineer should work together to ensure that labor cost, overhead and materials are reduced as much as possible. We should always strive to produce a quality product the first time and every time and Design for Manufacturing and Assembly can help!
Quality-One provides Knowledge, Guidance and Direction in Quality and Reliability activities, tailored to your unique wants, needs and desires. Contact Us Discover the Value! Reduce Quantity of Component Parts and Simplify Part Design The designer should review the assembly design part by part and determine if any part can be eliminated or combined with another part. Then ask the following questions: Can the part be manufactured using the same material as other parts?
How does the part in question move in relation to other moving parts? Can the parts be combined without need for any special process or tooling? If combined with another part how does that impact ease of possible disassembly? If combined with other parts how would it impact ease of manufacture? Design Parts for Ease of Fabrication The designer should consider the method of fabrication that may be used for producing the parts, the required material specifications and required production volumes.
Some particular guidelines to review are as follows: Specify materials that are commonly used and compatible with existing production processes that will minimize processing time and will meet all functional requirements Review the part and eliminate unnecessary features that could result in additional process steps, extra effort and complex or expensive tooling Design reviews with members of process engineering, quality control and the fabrication team are beneficial when possible.
In most cases the meetings result in a few changes to the design that increase utilization of existing tools or improve machine utilization, preventing the need for capital expenses for special tools.
In addition, the meetings improve knowledge transfer of design intent to all levels of the organization. Design Within Known Process Capabilities and Avoid Tight Tolerances The designer should become familiar with the process capabilities of any equipment required for the manufacture of the part. Utilize Common Parts and Materials Whenever possible the design should incorporate common parts and materials, including parts already in use in other similar products or assemblies.
Gradually, as you choose effective shape-forming processes and consider how to modify part features to lower cost, your product becomes cost optimized. A Highly Accurate Cost-Estimator Thanks to over 40 years of industry experience, DFM consistently provides accurate feedback on the change in cost associated with changes in parts or their design. Parts that are more expensive to produce than others will always yield higher cost estimates, and the amount of added expense is always correctly portrayed in the DFM results, something that historical pricing and automated CAD analysis cannot do.
Our approach to cost analysis provides superior accuracy because it correctly identifies each step required to manufacture the part and then quantifies each associated cost. An Easily Implemented Solution DFM software delivers complete and accurate should-costing capability right out of the box. After installing, you gain immediate access to thousands of potential process, material, and machine combinations. Should you wish to add additional capabilities, you can easily create new operations and open and edit all of the existing libraries.
Software training only takes a few days and generally results in users being completely self-sufficient in their usage. With DFM, there is no lengthy implementation or expensive customization necessary to begin enhancing your product development process. An Aid to Concurrent Engineering DFM shortens the product development cycle by providing early-stage cost transparency between design, manufacturing, marketing, finance and purchasing personnel.
The ability to share cost information during early stages prevents many of the hurdles that the typical product development team encounters when trying to get a product to the market. A Useful Design Tool Rather than simply providing cycle time and cost estimates, a DFM analysis educates the designer on the most important cost drivers of the proposed design.
The availability of this information is invaluable when deciding how the design should be changed to reduce cost. As soon as improvements are identified, new DFM estimates can instantly be generated to get accurate results for alternative proposals. The software reports all of the values and assumptions that are used to generate a cost estimate. This offers a purchasing department far more negotiating leverage than a basic quote could ever provide.
With DFM, supplier negotiation is about sharing relevant data instead of using pressure tactics to lower price. Engineers use DFA to reduce the assembly labor within a product through the consolidation of single function parts into more elegant, multifunctional designs. The DFM software is then used to help the design engineer quickly compare the costs to produce each alternative design. Used together, the DFM and DFA software give engineers an early cost profile for each product design and provide a basis for planning and decision making.
Such analyses, when performed at the earliest stages of concept design, have the potential to greatly influence manufacturing and other life cycle costs before they are solidified and become locked in place. It helps us analyze our designs and make decisions that lower overall costs, not just product costs. For pricing or to schedule a live demo, visit our contact us page. To view a demonstration of DFA basics, click here. Download the Design for Assembly Brochure. Click here to enlarge.
Harley-Davidson is working with its vendors to reduce costs while allowing the vendor his profit margins. The software accurately models part costs, providing a quantitative basis for evaluating competing design alternatives.
To view a demonstration of DFM basics, click here. For information on patents related to Metal Extrusion cost estimating, click here.
DFA: Product Simplification. Benefits of using Design for Assembly software Product engineers know that 85 percent of manufacturing costs are determined in the early stages of design. Use DFA software to: Estimate difficulty of assembly. Cost Breakdown, Cost vs.
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