Reliability Input into Design Reviews

Consider the following scenario: You are a reliability engineer working for a large corporation that plans to launch a new product. On occasion, you and the team sit down to review the design. The idea is to check the design for any issues with the combined wisdom of all the players involved. Or, perhaps, the review serves as just a status update for the entire team, providing a focus on the most important issues and action items.

The review may involve all departments: marketing, operations, supplier management, the design team, etc. It may involve just you and the electrical engineer in a private meeting. In either case, it is a review and offer a chance to illuminate salient reliability issues and form a consensus on the appropriate action.

Design reviews take many forms. The best I’ve seen include a presentation (more like a walk though) about the design, the constraints, and the key decisions and assumptions made by the designer of the product. The presentation is for those going to perform a detailed review and the purpose is to familiarize them with the details. Afterward, the reviewers have time to assess the design challenges, to form opinions and check hunches, to explore calculations and alternative solutions, and to formulate meaningful questions and identify challenges.

Then the group meets again and actually conducts the review. The focus now is on the questions, comments, ideas, and suggestions of the reviewers. Design challenges are discussed and possible best solutions are proposed. The action items often entail gathering more information, exploring alternative solutions, and supporting the final design approach.

Each design review also requires sufficient time to allow the actions to take place. A review in which the current status is assessed and everyone enjoys a refreshment or two is a simple sharing of information—not a gathering to improve the design.

With either the detailed technical or information-sharing design review formats, as a reliability engineer you have the opportunity to improve the design’s ability to meet the reliability objectives.

Goals

Of course, you have to have reliability goals apportioned to the element of interest for the review. This apportionment should have been done early in the project and only be a point of reference during the review. The goal itself may be a topic for discussion during a review. Is the goal appropriate given the current understanding of what is possible? What impact would changing the goal have on the customer, business, and design?

As the reliability representative, you need to ensure that the goal is present and included in the discussion. and be prepared to discuss the impact of changing the goal an all parties concerned.

Model and Estimates

Along with the goal, a reference to the current reliability performance of the design is necessary for any review. The current estimate is built with a model of the elements of the design and how the designed element fit within the overall product or system, reliability-wise. The idea is to compare the best estimated reliability performance of the current design with the goal. The gap, if it exists, provides a focus for any necessary reliability improvements. The focus may also be on improving the accuracy of the reliability estimate. Not all estimates are accurate.

For the detailed engineering design review it is appropriate to explore and discuss specific failure mechanisms and their associated physics of failure models, if they exist. You should also have recommendations to alter the design to improve reliability performance and an estimate of marginal improvement to reliability performance. Knowing the cost per failure can assist with balancing the cost of the change with lifecycle cost impact.

Reporting and Discussion

An essential element in a review is the clear communication of the comparison of the goal to the estimated reliability performance. A summary of the reliability model often provides the ability to present the elements of the overall product or system that meet their allocated reliability goals, and which do not, and by how much.

The focus then naturally progresses to those not meeting the goals. Keep in mind that reducing the reliability of one goal may require the increase of the goal in other areas to meet the overall system goal. Changing the system goal has impacts on the business and customer. Changes can and likely will occur, yet, when changes do occur, the entire team should be informed of the impact.

The discussion during the review, for either technical or status update formats, will eventually include a discussion of action items. Typical actions concerning reliability include the following:

• Explore alternative design solutions to improve reliability performance.
• Conduct research or experiments to resolve unknowns or uncertainties.
• Conduct a trade-off analysis to optimize the salient factors for a particular issue.

The intent is to incorporate reliability consideration into other review discussions and decisions, too. It is important to identify and work to resolve any design or project changes that will impact the system’s ability to meet reliability goals.

The details matter. The ability of the team to clearly understand the goals and the current estimates helps to focus the review discussion. Building understanding and guiding how to best move forward to meet the business and customer reliability objectives makes an impact across the team concerning reliability.

Reviews matter. Including reliability in every discussion matters. Being prepared and fully present with the team before, during, and after the review matters.

How do your reviews go? Do they make a difference?

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.