f m sre liabilit y.co m
http://www.fmsreliability.co m/educatio n/design-fo cus-2/
Decision Focus and Value
An essential element of a successf ul reliability program is the notion
that all reliability activity relates to decisions. If you are perf orming a
HALT because it is listed on the product development guidelines, or
because it was carried over f rom the last program’s plan, and the
HALT results are not part of the design improvement decision-making
process, then you probably should not be doing so. If the HALT
results yield little or no inf ormation (e.g., it is just being checked of f
the list as accomplished) then the HALT itself provides little or no value.
If perf ormance of a HALT is on the plan because the new product has new materials, vendors, or design
elements, then it may reveal weaknesses. If that list of weaknesses is made available to the design team
members and they are permitted and encouraged to improve the design based on that input, then the HALT
data can provide input to decisions about design improvements. T he value that the HALT plays here is related
to reduced f ield f ailures f rom design improvement opportunities discovered by such highly accelerated lif e
If the HALT is done too late to permit any decisions to improve the product, it has no value. If the HALT is done
to f acilitate decision making concerning design improvements, it may have great value. [Hobbs 2000]
Another example of decision making is lif e testing to estimate the expected durability of a product. At some
point in most product development processes there is a meeting to decide whether the product is ready f or
production and shipment. One element of this decision is the ability of the design to meet or exceed product
As an example, say a motor is the key element that will determine the lif e of the product and currently there is
uncertainty concerning the motor’s expected reliability perf ormance. T heref ore the team decides to conduct an
accelerated lif e test. If the test provides a meaningf ul estimate prior to the decision point on readiness, it adds
value. If the ALT provides results a f ew months af ter products start shipping, it adds little value f or the
readiness decision prior to launch.
During product development or maintenance planning two basic questions are of ten asked:
1. What will f ail?
2. When will it f ail?
T he various reliability tools provide inf ormation to address these two basic questions. If that inf ormation is
meaningf ul and timely (prior to the decision point) then the reliability tasks have value. Perf orming reliability
tasks simply to be doing reliability activities is unlikely to add value f or decision makers. Purposef ully using
reliability engineering tools to support decisions is very likely to add value.