While you can choose to develop a product without the involvement of manufacturing engineering in the process, doing so often isn’t the most efficient and cost-effective tactic in the long run. It’s like needing to be in another city, and choosing to drive instead of fly. Imagine you need to go on a business trip from Los Angeles, Calif., to Seattle, Wash. While driving will get you there, flying will be more efficient and cost-effective. In product development—with very few exceptions—there is a schedule and budget to keep, and the most efficient route all around wins. That means you will want to fly instead of drive. In this article, we will explore ways to get your product development process in the air with manufacturing engineering support guiding your journey.
The Right Team from the Start
One of the first actions should be to structure your team to include and enable manufacturing engineering from the start. Organizations typically create cross-functional teams to develop and deliver a new product. This approach allows multiple stakeholders to interact and balance the multitude of requirements throughout a project. Often, despite best intentions, manufacturing engineering is not fully involved until later project phases, which can be problematic. At this point, attempting to accommodate any manufacturing requirements could cause project delays or add cost. Instead, the best time to incorporate these requirements is before the product design is established. Therefore, prioritizing manufacturing engineering integration into the cross-functional team from day one is key to keeping a project on schedule.
The amount of time a development team works with a product is much less than manufacturing and operations teams. The difference in product ownership plays a role in the impact of any product issue. If there is an issue one must deal with once a month for a year, there isn’t sufficient motivation to fundamentally fix the issue. On the other hand, if the issue must be addressed every hour for three years, that is cause for action. Manufacturing negatively is impacted if the issue in this comparison is inherent to the product design. Manufacturing and operations teams are placed into a scenario of constant debugging instead of focusing on improving product quality and consistency. Thus, manufacturing engineers provide input that prevents this scenario when design changes are easiest to implement.
Input from manufacturing engineers ranges from design for assembly improvements to supplier strategy to selection of fabrication technologies. The input often is straightforward to implement when project commitments haven’t been made such as fabrication of tooling or completed design verification. For example, an assembly has a component with four possible orientations (Comp A) and is placed into a pocket on another component (Comp B) then sealed closed. The original design for Comp A requires it to be placed in Comp B in only two of the four possible orientations and the features of Comp A are small, making visual checks difficult. With manufacturing input, Comp A was re-designed such that all four orientations were acceptable which involved changing one feature. The simple modification avoided scrap by eliminating the opportunity for misassembles prior to sealing. Also, cycle time was reduced because an operator does not need to visually check Comp A orientation prior to placing.
Collaboration is Critical, Especially for Manufacturing
Collaborating with manufacturing partners is as important as integrating manufacturing engineers into the core team. These partners are any organization that will have final responsibility in fabricating, assembling or supplying a portion of the product. They provide a particular service or product to multiple customers on a regular basis. They should be considered experts as they focus on learning their trade and craft. A supplier has experience to guide design decisions but is not capable of executing design themselves. On the other hand, a development team has experience designing product but does not have in-depth knowledge of all manufacturing technologies. Manufacturing engineers understand this knowledge gap exists and can work to close it.
Selecting suppliers as early as possible and including them in the development process allows design decisions to be informed by industry best practices, process capabilities or limitations and even alternatives. Additionally, a supplier will have a greater understanding of critical features or components through the increased interaction with the development team. For example, a metal shaft requires a complex, 3-D bend that is critical to product performance. An initial attempt at applying geometric dimensioning and tolerancing (GD&T) to the shaft drawing was made without much supplier input. Internal drawing reviews did not reveal any errors or problems, so a pre-production build was kicked off. The pre-production units met all the drawing requirements but did not meet performance specifications. Previous iterations did not have this issue so the root cause was something other than shaft design. The supplier supported the investigation efforts, which lead to a drawing and measurement method review. The review discovered that the team’s measurement method of the shaft was not properly captured by the dimension scheme. The supplier and team co-developed the next drawing iteration, which resulted in significant scheme changes. The next pre-production run of shafts met all performance and drawing specifications, thus allowing the transition to production to continue. In this example, the supplier was essential in identifying the root cause but the delay could have been avoided. An additional review between the product team and supplier could have highlighted the discrepancy. This example focuses on drawing development, but the benefit of supplier collaboration applies to anything from design feature to process selection to supply chain.
Time: It’s Not Just for Design
The next key piece to enable manufacturing to support product design is budgeting project time for manufacturing development. Most business travelers lay out a schedule for transportation to the airport that accounts for various variables like traffic and security. Budget time for manufacturing development as one would for a timely arrival at the airport terminal before a flight.
New products often require a certain number of custom components to meet an intended function. There usually are similarities among components in the same category. For example, plastic enclosures for a diagnostic instrument all satisfy a similar requirement but each enclosure has unique features and design characteristics. These similarities can create a false sense of confidence that implementation will be without incident. That confidence manifests in insufficient time to investigate and debug a process. For instance, plastic press-fits have been implemented in several products and applications. It is a reliable and inexpensive method for joining two plastic components. It requires upfront effort to setup and stabilize the design and process. This initial effort could range from adjusting diameters to studying press force curves. It is a project and product risk to assume the press-fit will function perfectly straight out of the injection mold and in the arbor press. Instead, manufacturing engineers should provide insight about potential duration and technical challenge of these developments efforts. Capturing this insight in the schedule ensures a project focuses on the right hurdles at the optimal time.
An early manufacturing development effort accelerates a project in final phases and eases the transition to production. The acceleration comes from eliminating risks that negatively affect a project when manufacturing is in its critical path. Unique project strategies can be created to reduce risk if manufacturing engineering is incorporated into planning phases. A common example of not providing sufficient time to manufacturing development is the transition from prototypes to production. Rapid prototyping technologies are an excellent way to accelerate product development in initial phases. Unfortunately, some of these technologies do not lend themselves to supplying production volume. Thus, a transition to traditional production technologies must occur at a certain point.
This transition has various levels of risk opportunities depending on the project approach. For example, a printed circuit board assembly (PCBA) is manufactured at a rapid prototyping facility that is not the final production facility. PCBAs arrive on time, within budget and function properly so manufacturability isn’t given much scrutiny. The project advances to the point when the PCBAs fabrication switches over the final production supplier. Based on the prototyping success, deadlines are scheduled such that the first run of PCBAs must be delivered on time for testing. Unfortunately, there are several issues with component placement and the initial deadline is missed. Troubleshooting activities uncover a difference in fabrication methods between the rapid prototyping and production facilities. Difficult components were placed and soldered by hand instead of tape and reel. At this point, the project has sizeable risk of delays as the solution may require a late phase design change or significant process development. One of several methods to potentially avoid this hurdle could be splitting the second or third prototype iteration between the prototype and production facility. The quick turn from the prototype facility can keep the project moving while production facility delivers the order balance with a potential longer lead time. In this scenario, the production facility has at least one opportunity to build the PCBA and identify potential issues. That one opportunity could be sufficient in avoiding delays when production becomes a critical path. Manufacturing development requires time which can be minimized by pulling it further upstream or if avoided, creates delays.
Achieve Product Breakthroughs with Co-Development
Combining product and manufacturing development can elevate the quality and robustness of any new product. This combination requires integration of manufacturing engineering, focus and strategic planning to maximize its potential and effectiveness. If manufacturing engineering is excluded from any aspect, product design pushes manufacturing instead of a push and pull. The benefit of investing in co-development ranges from innovative products to high confidence and reliability. These benefits are achieved by the risk reduction that accompanies co-development. Risks often come and go during a manufacturing project, so co-development should not be viewed as a discrete activity. It is a continuous process and is important to incorporate into all phases of a project. Looking at an example of co-development will highlight the discipline needed to execute it properly and the benefits it brings.Product reliability and confidence is not dependent upon design alone; manufacturing plays a crucial role. Design and manufacturing can support each another in meeting performance requirements.
Collaboration between design and manufacturing increases the depth of knowledge on a technology, product or process. As mentioned before, it’ll take the proper structure, planning and focus to attain this knowledge. It can be leveraged to eliminate a variety of potential risks or react quicker to issues.
The foundation to establish is the link between three different product aspects: performance requirements, design specifications and process parameters. There are several approaches to developing these links but design of experiments (DOE) provides a structured and methodical strategy. In the previous metal shaft example, the team developed in-depth knowledge of the links between performance, design and process, which assisted in identifying the GD&T discrepancy. Development of the 3-D bend began with a course DOE that explored a wide design space. Factors and levels in the DOE were selected by the component design engineer, manufacturing engineer and component supplier. This cross-functional group was able to identify levels that easily were manufacturable and still probed the initial design space. After analyzing the results, another DOE was needed to focus on the optimum solution. The same selection process was used to determine the set of DOE levels.Nominal dimensions and tolerances were driven directly by the results obtained in the second DOE.
Although sufficient samples were used in each DOE, fabrication of the shafts did not represent typical production environment. Another DOE was executed on key process parameters on equipment at the supplier. This experiment creates two links—design specification to process parameters and product performance to process parameters. The links are created by combining results from the design and process DOEs. The analysis showed a portion of the process space did not produce acceptable components. Therefore, the nominal process settings and tolerances were set such that the incapable process space is avoided. In the end, this development effort enabled the team to understand natural variation in design and process and eliminate performance drop-offs due to that variation. Design and manufacturing are required to fully understand a component and its fabrication, otherwise only a portion of the puzzle is revealed.
The Best Resource to Solve Production Issues is the Development Team
Pulling infancy failures from manufacturing prior to product launch is another technique to improve product quality. There often is a noticeable difference in quantity produced during product development and production. Due to this difference, machines, equipment and fixtures do not have many hours of use prior to launch. Therefore, glitches, bugs or errors could still exist that can cause unexpected downtime or scrap. Each error that is identified and resolved improves production stability. While the development team still is engaged with the project, it is the perfect time to resolve these early manufacturing issues that will lead to faster production stability. The benefit of having a development team available is its intimate knowledge of the product and design. It will be easier for the team to assess whether the glitch negatively impacts performance or if a solution must be implemented. The team’s resolution could involve design or process modifications or a shift in expectations.
One method of extracting infancy failures from production is to perform equipment run-off prior to production launch or line transfer. This run-off is an opportunity to build a small batch of product at near-standard production settings. Making equipment run-off a part of the development team schedule ensures that team support still will be available during this critical time. For example, an end-of-line test used a custom machine to exercise several buttons and ensure a diode was functioning properly. A similar machine had been built in the past for a different product and the new machine mirrored the design and construction of the predicate. During equipment runoff, the product failed an end-of-line test at a low occurrence rate. Despite the low rate of occurrence, the development team investigated the root cause of the failure and found the diode had shorted due to electrostatic discharge (ESD). The manufacturing team used the information to implement proper controls to eliminate the problem.
Without this equipment run-off, the ESD issue would have occurred during qualification of the production line and it would not have passed the qualification protocol, causing delays. Although this example is fairly benign, it is possible that larger issues could be “hiding around the corner” in an assembly line. Knowledge maturity reaches its peak near the close of a project, which enables the development team to reach quickly and purposefully. Once this window passes, root cause efforts rely on research of history files and records, which can be tedious and time consuming. Instead, use the development team to knock off the low-hanging fruit before the product hits the market.
Get There Faster, Take a Flight: Invest Early in Manufacturing Engineering
Product development is a challenging process that requires a balanced risk management approach. There are risks that can bring breakthroughs in product value and others that can derail a project. Those derailments inevitably will occur if a discipline’s risk is pushed to later phases, especially manufacturing engineering. During the first 20 percent of the development cycle, approximately 80 percent of the product cost, quality and manufacturability are established. Without a manufacturing engineer’s voice, opportunities as well as threats to achieving or exceeding market potential will be missed. Addressing any late product issues will require more time and money than planned once the moment has passed.
Driving around the country from meeting to meeting would wreak havoc on productivity and effectiveness. Manufacturing engineering lets you reach your destination with efficiency and go farther than ever before. It can provide insight to avoid delays, cost or poor quality in addition to reaching new heights in product performance and value. Leverage these benefits on your next project by bringing the manufacturing voice into product development, budgeting for manufacturing development and targeting manufacturing risks early.
Danius Silkaitis is a manufacturing engineer at Seattle, Wash.-based Stratos Product Development. He works with Stratos clients to plan and prepare for the transition to production in addition to identifying and mitigating manufacturing risk throughout the development process. Prior to joining Stratos, Silkaitis worked for Ethicon Endo-Surgery, a Johnson & Johnson subsidiary, developing manufacturing and assembly operations for energy-based surgical devices. He has experience with a variety of components, from custom machined titanium parts and piezoelectric ceramics to injection molded parts. He has managed suppliers through the product development process as well as launched new product assembly lines. Silkaitis holds a BSME from Purdue University and a MSME from the University of Michigan. He can be reached at danius@stratos.com.