Monthly Archives: January 2013

Why Reliability?

Reliability has several definitions, mostly covering some likelihood expression of functionality under certain conditions and a given timeframe. And designers and manufacturers often put significant effort into preventing failure. But this begs the question of “why?”

The answer is that reliability is a potential benefit to the user and, through sales and profit, to the supplier. Benefits come in the form of safety, of the product confidently delivering its intent, and of lowered operating costs. However, there are also potential downsides, of a higher up-front cost, changed aesthetics, less performance, etc. And, sales may be driven by these more visible attributes. Hence, benefits to the supplier of maybe increased investment (to deliver assured high reliability) might be negative without increased sales and / or profit margin. And perhaps development of improved reliability could delay product launch and thus lose key marketing opportunities.

Hence, we must recognize that reliability is a competing attribute.

So, how to compete?

Compete on cost by presenting operating $ benefits. Compete on performance by factoring % success. (There’s no point in having a high performance aircraft that never completes it mission.) Relate cost of warranty returns to direct loss of profits. Factor reliability and product assurance (including more generous warranties) into marketing activities, such as focus groups, to highlight potential gains in sales.

And remember that good reliability is often achieved simply by ensuring good quality. There are many instances where poor supplier and manufacturing quality generate far more warranty returns than “design” reliability issues. And good supplier and manufacturing quality can often be achieved at low cost, and has no negative impact on product performance.

So, to be effective, a reliability engineer should use the tools of marketing, field service, supply chain management, quality and accounting departments (as well as design), and be a positive agent in developing corporate strategy. Without these links, we would miss several opportunities to best optimize products for customers and supplier alike.

Question: Where does the reliability engineer go to learn those tools, beyond forging links with these several departments?

Commercial grade wind turbines generally have a target design life of 20 years.  This goal is frequently elusive with key components like the gearbox often showing much shorter life in service.

Continuous condition monitoring and motion control are technologies which are beginning to improve the reliability of wind turbines.  Condition monitoring can reduce downtime by advance warning of the problem and in some cases making simpler repairs as opposed to full replacement.

There are many ways for advanced monitoring and control technologies to improve the reliability of wind turbines.  For more details, see the article at:,aid_254889&dfpLayout=blog