  Reasoning about safety, security, and other dependability attributes of
autonomous systems is a challenge that needs to be addressed before the
adoption of such systems in day-to-day life. Formal methods is a class of
methods that mathematically reason about a system's behavior. Thus, a
correctness proof is sufficient to conclude the system's dependability.
However, these methods are usually applied to abstract models of the system,
which might not fully represent the actual system. Fault injection, on the
other hand, is a testing method to evaluate the dependability of systems.
However, the amount of testing required to evaluate the system is rather large
and often a problem. This vision paper introduces formal fault injection, a
fusion of these two techniques throughout the development lifecycle to enhance
the dependability of autonomous systems. We advocate for a more cohesive
approach by identifying five areas of mutual support between formal methods and
fault injection. By forging stronger ties between the two fields, we pave the
way for developing safe and dependable autonomous systems. This paper delves
into the integration's potential and outlines future research avenues,
addressing open challenges along the way.
