Reliability Bounding: A Primer

Picture of Adam Bahret
Adam Bahret
Gra35 PFB

I introduced the concept of ‘Bounding’ in my book Reliability Culture and since then the idea of Bounding has surfaced in many of my posts. This blog article summarizes all those mentions in a single place for the reader.

Let’s first define what Bounding is. In any Product Development, there are multiple incentives competing to drive the program in a direction that suits it without considering the highest-level business goals. Every team & personnel involved in the product development in an organization have an incentive structured by the layout of their contract. Some are paid bonuses, some are measured on count of patents filed, some are responsible for saving costs. Who wins? and what will be the impact to Business when others lose?

Ratio Factors
Product Ratio Factors

At the top, a product will need to balance its factors. Represented here as ‘Product Factor Balance’ (also known as Ratio Factors) they consist of Time-to-Market, Product Cost, Features, and Reliability. All the factors must exert equal influence in making the design decisions. But most often, the shape is not a perfect diamond like Tiffany’s. It will be skewed to elongate on one end to meet the unique needs of your product type & its specific application. Think of Military Drone vs Recreation Drone. Both have same features (fly & take pictures) but their Cost, Reliability and Performance are different.

The balance of the Ratio Factors are constantly changing as product development moves from Prototype to Manufacturing. Come mid-program, you may get questions that you couldn’t have planned for at the start: “Do the three additional months requested for the Accelerated Life Test (ALT) completion
justify the later time to market?” “What do we do when we don’t have a high confidence the product is going to last as long as promised?” “Should we release it late which may cost market share just to do more testing for increased confidence in long life?”. Historically, these decisions are made ambiguously. Mostly based on who yelled the loudest at the Friday steering meeting. Or, more importantly, who can make the biggest case that their scenario leads to better market share, whether it’s quantifiable or not. But Bounding method gives an objective way to tackle this problem.

The Reliability Bounding method starts by setting up a numerical decision-making scale called the ‘Bounding Number’. It’s like a ranking system created by your team and accepted throughout the organization as a way to make objective & quick decisions. Companies care about the Return on Investment (ROI) in their businesses. So when a new Reliability investment is made, they would want that investment to pay off well. A ‘Bounding ROI’ is a method to quantitatively evaluate the ROI of an investment. By following through on the steps, you can decide if you want to do 3 more months of ALT testing or launch the product without doing any testing. Sounds neat. No team member will be disappointed that their voice is not heard or no bureaucracy will slow things down. This method is meritocratic. The following graphic explains the steps of creating the Bounding ROI tables.

Gra BoundingROI
Establish Bounding ROI

Then the Reliability Bounding method uses the above table at all points during the product development. When another folk in the road appears due to a new safety risk identified in the design or a supplier failing to provide parts, a decision must be made on how to proceed further. The table is referred here and all possible options are listed and scored. When a particular recommendation of doing a re-design to eliminate safety risk scores high in ROI (Invest Score is greater than Return Score as per table above), then you can slow down the program to re-design. You will not have any qualms about missing the product business goals as they are considered in your decision.

Over the last few years, I’ve applied this Bounding method with my clients and they love the simplicity it brings into the conference room. Hoping you find usage at your organization. Reach out to me and share your stories of success or frustrations.

Share this post