How to have clear reliability conversations

The importance of conversations

Wayne Nelson once said during a conference, “The words we use matter”. I agree. I think using MTBF in conversation should be avoided. This is not a surprise those that know me.

We do and should have meaningful conversations about reliability. To improve those conversations consider the words you use. Reliability is the probability of survial over some duration for stated set of conditions and expected function. It is the probability and duration that often gets muddled.

Beyond avoiding MTBF, when was the last time you really talked with others about reliability? What is it they expect? How do they talk about thier expereince with your product?

with your team

During a reliability assessment I had the chance to talk to two engineers and thier manager working on the same project. One of the first questions I ask is, “What is the reliability goal for your project?”

The first engineer said it was 50,000 hours MTBF. Great. “What does that mean?” He explained that that is a very high standard and difficult to achieve with thier product. So, he selects the most expensive parts, uses component derating very conservatively and requests as many tests as time permits.


The second engineer also said the goal was 50,000 hours MTBF. At which point I noted the consistency and common knowledge about the goal And, he responded that the goal was easy to achieve. He selects the least expensive parts, pays little attention to component derating, and rarely request product testing.

They are working on the same part of the same product. Not so impressive.

The third interview is with the team’s manager. She says the goal is 50,000 hours MTBF. And, since we don’t measure it, it doesn’t mean anything.

There seems to be a communication breakdown beyond the misunderstandings around MTBF.

To help, be clear when talking about reliability. Use clear and complete goal statements. Discuss what the goal means and implies for engineering decision making.

with your suppliers

We often rely on our suppliers to provide reliability information for our consideration and use when estimating reliability for a product or system. We can improve the conversation by asking about reliability.

Include in the converstaion:

  • The function of the subsystem or system using the suppliers part
  • The environment around the supplier’s part
  • The desired probability of success (percentage surviving)
  • The duration over which the part should survive

This is a full reliability statement. It conveys the information for a good conversation around reliability. If we want the part to meet our needs, and those of the customer, we should be very clear on what we expect.

When intrepreting supplier reliability information, use the same four elements. Be clear that we fully understand the information they are providing.

with your customers

When asked customers just want the product or asset to work. To be easy to maintain in a cost effective manner. Customers understand failure will occur and would prefer failures to occur with someone else.

Customers rarely provide a full relaibilty statement worth of information around what they want. It is our conversation with them to understand the four elements.

Just as with suppliers, we need to use the four elements of a complete reliability statement when discussing reliability with our customers. Furthermore, asking what product failure means to them – i.e. what is the impact of our product failing? Ask about importance, reliance, trustworthiness, and related facets of reliability.

Our brand image is made up of customer’s preceptions. We should understsand how reliability plays a role in our brand. Entering conversations with our customers is a great way to make that happen.

with your peers and colleagues

When we talk to each other, we really should be clear about the terms and acroymns that we use. We may assume we have a common understanding with terms in regular use related to reliability.

I’ve found that to be untrue.

Therefore I highly recommend checking for understanding regularly. Again, when talking about reliablity use all four elements of a complete reliability statement. And, always use couplets of duration and probability to avoid any confusion.

It is our conversations with each other where we learn and grow as professionals. Let’s make those conversations meaningful by using clear language.

The words we use matter in the conversations we enjoy. Let’s be clear when talking about reliability.

About Fred Schenkelberg

I am an experienced reliability engineering and management consultant with my firm FMS Reliability. My 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.

5 thoughts on “How to have clear reliability conversations

  1. Unless an entity such as an engineer or organization understands and influences the human interaction with the system or component, reliability cannot be predicted. Countless studies show that the majority of failures have a root cause at the human interaction. If human interaction (behavior) is not highly managed, there is no predictable reliability, let alone MTBF.

  2. Dear Fred,

    I agree with above..but at the same point it is vital to device if there is any term / figure refer reliability in true meanings. If in case there is not, then how to evaluate and demonstrate reliability of certain equipment / machine / tool in true meanings.

    I am also working to device an alternate of it. till the time alternate is not devised people will be unconcerned with what ever anomaly MTBF inherent in it.

    Rgds Saif (Reliability Engineer)

  3. But at the same time your efforts in highlighting the facts also stands appreciable.

    Rgds Saif (Reliability Engineer)

  4. Hi Saif,

    Thanks for the comments – you are right, if we don’t understand the product and the reliability than it really does not matter how we talk about it.

    Our work as reliability engineers is always interesting. Let’s make the language we use clear and the estimates accurate (as possible).



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