Systematic faults are often a result of an error

Error

The word error entails different meanings and usages relative to how it is conceptually applied. The concrete meaning of the Latin word "error" is "wandering" or "straying". Unlike an illusion, an error or a mistake can sometimes be dispelled through knowledge...

 in the specification of the equipment and therefore affect all examples of that type. Such faults

Fault (technology)

In document ISO/CD 10303-226, a fault is defined as an abnormal condition or defect at the component, equipment, or sub-system level which may lead to a failure....

 can remain undetected for years, until conditions conduce to create the failure

Failure

Failure refers to the state or condition of not meeting a desirable or intended objective, and may be viewed as the opposite of success. Product failure ranges from failure to sell the product to fracture of the product, in the worst cases leading to personal injury, the province of forensic...

. Given the same circumstances, each and every example of the equipment would fail identically at that time.