Quality during Design Blog

Listen • Read • Access Bonuses • Find Inspiration.

Updates

Podcast

Apple Podcasts

Spotify

"Dianna Deeney has launched a podcast that focuses on both the need and the 'how to' include quality and reliability in your design. Both entertaining and thoughtful, the shows are well done and worth subscribing."  

Fred Schenkelberg, founder of Accendo Reliability 

Search

Want to be a guest?

I like talking with people in product design and the manufacturing industry. Contact me if you're interested in being interviewed and being a guest on the show.

The Kill Criteria: How Tesla Decides Which Battery Innovations to Pursue (And Which to Abandon)

At Tesla’s 2020 Battery Day, Elon Musk promised a 56% cost reduction and 69% CAPEX (capital expenditure) reduction through revolutionary dry electrode technology (Manthey, 2020). Three years later, Tesla quietly pivoted to a hybrid approach, delaying their volume ramp. Why did Tesla abandon a technically superior solution? Because innovation without business viability is just expensive…

Define Kill Criteria to Avoid Zombie Projects

Engineers are masters at defining success. We establish “go criteria” based on user needs, requirements, and performance requirements that our product must meet. Take, for example, Tesla’s battery development program, which aimed for aggressive targets like a 56% reduction in battery cost per kilowatt-hour and a 54% increase in vehicle range. To meet such targets…

Choose it: How to Decide Between Viable Options When You’ll Never Have 100% Confidence

You’ve spent 6 weeks and $50K investigating three materials. Your confidence has climbed from 40% to 60-85% across options. Your manager asks: ‘Which one? Are you sure? Should we test more?’ Real decisions involve trade-offs between confidence, cost, timeline, and performance. In Phase 1, we identified a High Impact/Low Likelihood decision (40% confidence). In Phase…

Beyond the Perfect Test: Building Confidence Through Strategic Testing

Industries with high consequences (medical, aerospace, automotive) have evolved sophisticated testing strategies that balance regulatory requirements, budget constraints, and time-to-market. Great engineers don’t find the perfect test. They stack imperfect evidence until confidence exceeds the decision threshold. We introduced evidence stacking in this month’s AMA: “Investigate It: How to design tests that actually move your…

Confidence Is A Dial: Turn It With Evidence, Not Guesswork

We turn late-stage design surprises into a strategic plan by assigning explicit confidence levels, stacking evidence, and using the three-dial model of time, cost, and confidence boost. We show how to work backward from a system test to cheaper steps that drive faster, clearer decisions. • applying the three dials of time, cost, confidence •…

Investigate It: How to design tests that actually move your confidence needle, and when to stop.

We have a tough, uncertain design decision ahead of us. Everyone agrees we must do something, like extra tests or analysis. We’re not moving forward until we address this critical unknown in our design process. Now we want to do activities that actually move our confidence needle, and know when to stop. Last month, we…