Focus on problem prevention There are two basic approaches when addressing product reliability: Reactive or Proactive. Neither is right or wrong. The reactive approach has the limitation of responding to failures that occur during prototyping, production and customer use. The proactive approach focuses on preventing product design, assembly, and use issues before they have the opportunity to create a product failure. Reactive Approach The reactive approach focuses on identifying failures, conducting root cause analysis and implementing the appropriate corrective action. This may include redesign of the product or a change in suppliers. Designers often find having a concrete product failure essential to solving reliability issues.

1. fmsreliability.com http://www.fmsreliability.com/education/two-approaches-reliability/
Fred
Two Approaches to Reliability
Focus on problem prevention
There are two basic approaches when addressing product reliability: Reactive or Proactive. Neither is right or wrong.
The reactive approach has the limitation of responding to failures that occur during prototyping, production and
customer use.
The proactive approach focuses on preventing product design, assembly, and use issues before they have the
opportunity to create a product failure.
Reactive Approach
The reactive approach focuses on identifying failures, conducting root cause analysis and implementing the
appropriate corrective action. This may include redesign of the product or a change in suppliers. Designers often find
having a concrete product failure essential to solving reliability issues.
This approach does have the limitation of waiting till something goes wrong before taking action.
The reactive management style is characterized by the only time senior management pays attention to product
reliability is when there is a major field failure problem. The basic message from management is to focus on time to
market, bill of material cost or product functions and not reliability.
In some cases, the individuals that are particularly adept at solving field failure issues are rewarded and considered
heroes. This culture quickly devolves to one where field issues regularly occur pulling engineering talent from new
product design tasks.
A culture of responding to reliability failures may require significant engineering resources to address field issues. An
estimated [Fred’s experience with reliability program assessments] 25% of engineering talent may be committed to
addressing design and manufacturing errors related to reliability. Some organizations create entire departments, i.e.
sustaining engineering, to ‘shield’ the product design teams from the re-engineering of products failing in the field.
Proactive Approach
The proactive approach focuses on preventing failures.
No design is perfect, yet some are better than others especially concerning product returns or lost sales. A product
that does what it is expected to do and does it over time is considered reliable. The HP calculator had that reputation
and associated very low field failure rate.
The investment into creating a robust and durable design requires informed design practices, discovery of failure
modes and mechanisms, and resources to permit essential design evaluations and improvements.
It is the combination of setting a goal and measuring progress toward that goal that enables the design team to
knowingly create a reliable product. Measuring reliable both in terms of failure rate and in money enables the entire
design team to make informed decisions that consider the impact of cost, time to market and reliability.
The proactive approach uses a range of tools prior to failures occurring to understand and design to avoid a wide

2. range of possible failure mechanisms. This requires an understanding of materials, design performance, product use
and environment.
The proactive design for reliability approach attempts to fully understand the full range of stresses and incidents that
may occur to the product and then to design a product that will continue to function within that environment.
It may not be feasible to create a product that will work across every set of possible stresses the future individual
products may experience, yet making informed decision’s that minimize the field failure rate and customer experience
is possible.