DFMA: Design for Manufacturing and Assembly with Sustainment throughout the Product Lifecycle

Raytheon Design for Manufacturing and Assembly (DFMA®) is an integral part of the design process that ensures the manufacturability and affordability of products and processes. While achieving customer requirements, DFMA puts an emphasis on design, fabrication, assembly, integration, test and sustainment. It is the methodology for designing products and systems to more effectively utilize overall manufacturing and assembly processes. Collaboration is critical to the success of DFMA, as the design of a product is optimized when there is cross-functional participation from Engineering design teams and from operations and other disciplines’ subject matter experts (SMEs).

WHY DFMA?

Understanding every aspect of customer requirements as early as possible in the design process is an important part of staying competitive in the defense industry. Raytheon programs face the challenge of defining product requirements and developing robust designs under increasingly greater need for quality, lower cost and reduced schedule. Utilizing DFMA provides an advantage by addressing three key program metrics: Total Ownership Cost (TOC), Design Cycle Time and Cost of Poor Quality (CoPQ).

Design decisions can drive the TOC of a program, which includes elements of the program Life Cycle Cost as well as other infrastructure or business process costs not normally attributed to the program. New programs, therefore, as well as major upgrades to existing programs, have the greatest potential for TOC reduction. When applied at the earliest design stages of a program, DFMA practices have the greatest impact on the TOC, and reduce the overall design cycle time.

Studies by Boothroyd Dewhurst on products, with and without DFMA, across hundreds of businesses concluded that performing DFMA early in the concept phase of a product results in fewer disruptions in subsequent phases, requiring less change notices and rework. The result is an average of 40 percent reduction in design cycle time (Figure 1).1 With early DFMA, what normally involves a stepwise peer review through Quality, Operations and other functions becomes a proactive real-time closed loop feedback that influences the design starting at conception.

Figure 1: An early DFMA strategy provides reduced design cycle time

Cost of Poor Quality (CoPQ) is the costs associated with poor quality products or services which, in some cases, can result from poor designs. Quality issues throughout the program lifecycle can be reduced when production and sustainment information on process capability, cost drivers, cycle time, yield and defect opportunities is available early on to support data driven design decisions. With DFMA, engineers can predict and minimize manufacturing, assembly and sustainment risks early in the development process.

Examples of DFMA principles combined with cross team collaboration help to highlight these ideas. In a recent Raytheon printed wiring board (PWB) design activity, engineers engaged independent subject matter experts (SMEs) and the PWB supplier to create a more affordable design. Collectively, the team was able to create a list of more than 50 improvement ideas, prioritize the list through use of an ease and impact assessment and, finally, produce a recommended set of cost reduction activities. The recommendations included elimination of four layers of the PWB, an increase in panel utilization (# of boards per panel), optimization of the plating process, and improved PWB yields. In the end, the effort resulted in a greater than 25 percent cost reduction.

In another example, DFMA and Agile/Lean principles were used to meet the performance and cost targets of a product chassis. Engineers and SMEs from multiple program disciplines leveraged both manufacturing and test process capabilities to reduce weight and cost of the chassis.

In this instance, more than 30 improvement ideas were again prioritized through an ease and impact assessment to produce a set of cost reduction initiatives that resulted in 31 percent fewer parts and a greater than 40 percent cost reduction for the chassis.

DFMA with Sustainment (DFMA/S)

Raytheon has built upon the generally accepted principles of DFMA to better meet sustainment goals and the requirements of the industry in which the products are deployed. There are 15 Raytheon DFMA/S principles (Figure 2) that provide the foundation for reducing the complexity of the design and assembly sequence along with identification of alternative manufacturing processes, all of which helps to reduce the overall cost and complexity of production, integration and sustainment. The first 11 principles address simplicity of design, minimizing both parts and operations steps while meeting product requirements. These also stress using standard, easy to assemble, self-locating parts that do not require special tooling. Raytheon has modified these industry standard principles (highlighted in white) to better support sustainment, product use and maintenance by end-users.

Figure 2: Raytheon’s 15 principles of Design for Manufacturing and Assembly with Sustainment (DFMA/S)

DFMA/S at Raytheon incorporates three methodologies: DFMA/S workshops, Integrated DFMA/S (iDFMA/S) workshops and Concurrent Engineering.

DFMA/S workshops are collaborative events, led by a facilitator, that utilize DFMA/S principles and tools to identify design simplification ideas. These are typically larger cross-functional meetings of 12 or more people that focus on system level assemblies and are often held in one of Raytheon’s Immersive Design Centers (IDCs), Figure 3. IDCs provide an ideal collaborative space with 3D capability in a CAVE Automatic Virtual Environment where a team is immersed in virtual technical content with real-time model interrogation and idea capture. Here, using 3D models or prototypes, they are able to investigate early on, producibility issues such as operator physical interference, ergonomics issues during component manipulation and/or assembly tool accessibility limitations. Workshop activities are documented using a DFMA/S template from the Raytheon Six Sigma toolkit and an implementation plan with prioritized recommendations is produced.

While also a collaborative event, an iDFMA/S workshop is smaller in both size (usually only three to five people) and scope. Its narrowed focus is defined by product cost or size of the design; circuit card assemblies, interconnects and sub-components for example. The iDFMA/S workshop also uses the DFMA/S template to create a prioritized recommendations list and implementation plan.

 

Concurrent engineering involves using a cross-functional team to simultaneously design products along with associated manufacturing processes and sustainment methods. By integrating quality, operations and product support functions into the design and development process, trade studies on all critical processes and product areas can be performed concurrently. For example, studies may include production process capabilities, manufacturing costs, special tooling and test equipment along with manufacturing and sustainment issues such as material constraints and availability, field accessibility, special training requirements, and ergonomics.

When combined, the three methodologies form a foundation to help integrate DFMA/S across the enterprise, providing consistency in both application and focus for cost-effective manufacturability, quality and sustainment of Raytheon’s product lines.

Beyond DFMA/S, Design for “X” 

Going beyond the DFMA/S umbrella, Design for “X” (DfX), where X is a variable with many possible values, adapts the standard DFMA/S infrastructure processes, tools and people to influence and simplify other product development opportunities. For instance, DfX may include Design for: Automation, Test, Safety, Human Factors, Corrosion Mitigation, Additive Manufacturing or Facility Optimization. In all cases, understanding a program’s requirements and involving a program’s process experts as well as cross-functional influences is paramount to a successful DfX activity.

Figure 3: The Immersive Design Center provides an ideal setting for cross-functional team collaboration

Summary

DFMA/S is being used throughout Raytheon to reduce design cycle time, improve producibility and sustainability, and to promote cost competitiveness during product development. Resources are available across the enterprise through a DFMA/S website and the Raytheon Six Sigma toolkit for organizations to utilize the wealth of experience, tools, processes and methods key to developing the most efficient design solutions for customer mission success. DFMA/S is a product development best practice and is essential to how products are designed and improved at Raytheon. Although leveraged in the early development phase of a product, DFMA/S provides significant savings through the product lifecycle, and it helps ensure that systems are manufacturable, affordable and sustainable.

— Maria Spalt & Mark Steudel

 

1 Boothroyd G., Dewhurst P., Knight W. A., “Product Design for Manufacture and Assembly” Second Edition, (Boca Raton, FL, CRC Press, 2001)