What is “design for reliability” (DFR) and how would you recognize it if it was occurring? Is it possible for an individual to ”do” DFR? Is design for reliability a specific technique? Like meditation, nearly anyone can strike a pose that appears similar to someone in deep meditation, yet can you tell by observation if that person is really mediating? Probably not. The same is true for organizations or people declaring that they are doing DFR. Maybe they are—or maybe not.
WHAT IS DFR?
Design for reliability is a collection of tools and techniques that address the reliability aspects of a design. The tools focus on creating a robust product and one that meets the reliability objectives.
Technically one person could perform all the various activities. That person could calculate the safety factors built into the design, estimate system life, and explore for weaknesses. It would be a challenge just to accomplish all of the various tasks during the product development phase. Would that be a DFR program? No, not really, as just accomplishing a range of tasks is not sufficient to impact the resulting system reliability.
Beyond the specific tasks, DFR entails decision making within the organization. Keep in mind that the resulting reliability is designed into the product. The process of product design involved thousands and thousands of decisions, each one affecting the reliability performance. The decisions by each member of the design team include to some extent an element of reliability. A DFR program in which the impact on reliability of each decision is considered is an effective program.
WHAT CAN WE OBSERVE TO SEE DFR IN ACTION?
The various tools and techniques used in DFR include:
• Increasing awareness of how decisions impact reliability,
• Revealing connections between design elements of reliability,
• Providing feedback on expected reliability performance,
• Exposing weaknesses that limit reliability, and
• Confirming design strength and robustness.
The individual tools provide value directly, yet in combination and distributed across an organization a DFR program enhances the capability of the design and development team to create a reliable system.
When the team is making decisions related to product design including reliability factors, then you are doing DFR. When the team discusses design aspects that naturally include reliability, that is DFR. Anyone can raise meaningful reliability questions and pursue the appropriate experiment or analysis.
An electrical engineer has many options for discrete components. Beyond the electrical properties the selection of a specific component includes the component’s failure rate. When the engineering team also considers the impact on field failure rates and cost of unreliability, when selecting a component, that is DFR.
The ability to consider the impact on unreliability costs requires the awareness of the cost per failure or similar information. One technique is to calculate the cost of warranty per unit shipped. This changes the vague warranty expense line into a measure on the same scale as the cost of individual components.
As with meditation, it is the process, how we think and make observations, that matters. The range of tools and techniques should change for each circumstance. Practicing and mastering the tools takes time, yet the gained wisdom allows us to guide the organization to create robust and reliable systems.
Bio:
Fred Schenkelberg is an experienced reliability engineering and management consultant with his firm FMS Reliability. His passion is working with teams to create cost-effective reliability programs that solve problems, create durable and reliable products, increase customer satisfaction, and reduce warranty costs. If you enjoyed this articles consider subscribing to the ongoing series at Accendo Reliability.