Concurrent engineering is a common approach that pairs the development of the product design and it’s supporting manufacturing processes through the development process.
Design engineers may require the creation of new manufacturing processes to achieve specific material properties, component performance, or mechanical, electrical or software tolerances.
Yet, if the design engineers fully understand the manufacturing capabilities and the full range of impacts and risks to process yield, quality and reliability performance, they can make informed decisions concerning their design requirements.
Part of every decision
Making good decisions during design creates value. You can estimate the value by the magnitude of the span of outcomes for the decision.
On the other hand, the manufacturing engineers learn earlier and first hand what is critical to the performance of the product. They develop an intimate knowledge of the design and understand those critical nuances not including on drawings or specifications that impact the product’s functional and reliability performance.
The discussions between the design and manufacturing teams often reveal areas of risk. Including a reliability engineer in these discussions may then extend the discussions to include the risks to meeting reliability objectives, too.
Better, if the design and manufacturing engineers are able to fully consider the reliability impact on customers, they can incorporate that information into their decisions.
Existing programs
Six Sigma
Design for Six Sigma is a design approach that strives to achieve designs that are robust to the expected part and manufacturing variation that will occur.
By understanding the process capability for a part and setting design tolerances such that the expected range of variation (+/- 1.5σ) minimizes the parts contribution to system failures due to the component being out of tolerance, thus not working.
Design for Six Sigma extends to reliability as designs that are robust to manufacturing variation tend to be robust to changes to parts over time. As the material properties decay, or polymers deform, or capacitance drifts, the robust design permits the system to continue to function normally.
It is not always possible to achieve wide tolerance specifications for a given component capability, yet those become a focus for the team to improve the process or include system monitoring to avert system failures, when possible. The concept of stress — strength applies here and directly connects to field reliability performance.
If the organization is using the design for six sigma during the design process, it also permits the team to identify elements of the design most at risk. The risk extends beyond manufacturing yield, as parts that are marginally acceptable tend to be less reliable overall.
Another aspect that connects to reliability performance is the notion of process control and stability, which again in itself improves field reliability performance or at least predictability of reliability performance.
Lean
Lean is a program that strives to reduce waste from a process or design. The program includes the careful examination of a process to indemnify and remove or minimize any unnecessary action, manipulation, storage, delay, etc. The intent is to make our processes as efficient and streamline as possible, where every step adds value to the product.
Lean tends to illuminate areas that increase reliability risks (extra handling or movement increase chances of damage, for example). Furthermore, lean practices tend to reduce the need for testing, evaluation, and monitoring as the opportunities for mistake reduce.
A simple example is a lean design may use a single type of screw with one torque setting. The manufacturing process removes all but the one type screw and uses a single torque driver to install the screws. This eliminates the parts and tool management overhead for many parts and tools, plus streamlines the operator training and decision making when addressing this one part.
Extend the lean concept across a product and it improves the ability to the design and manufacturing process to create the product correctly. Thus improve the field reliability performance.
Emerging Technologies occur, it seems, at an increasing pace. New techniques, procedures, materials, attachment schemes, and more arrive nearly every day. A general guideline is to flag for additional attention anything that is ‘new’. New to our industry or customers, new to our design or manufacturing process, or new to our way of thinking.
As reliability engineers, we examine and attempt to characterize anything new with respect to the impact of field reliability performance.
A few basic questions often start with how will it fail and when will it fail. While this is a rather negative approach it helps the entire team understand any limitations or boundaries concerning reliable performance for the new material, component or process.
Summary
Considering product reliability occurs as a result of the many decisions across the organization.
Plus the scope of reliability engineering spanning the entire product lifecycle and involving nearly every aspect of bringing products to market or operating a plant, we have to hone our skills to understand and advocate for the inclusion of reliability thinking with every program and process across the organization.
By broadening the conscious consideration of the impact of a decision on the eventual impact on reliability, we in effect expand our reach as the reliability professional and our effectiveness in creating reliability products and processes.
Related:
Material Selection & Reliability (article)
When is the Best Time to Establish Reliability Goals? (article)
Key Elements for Your Project Specific Reliability Plan (article)
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