How is a malfunction defined?

A malfunction is defined as the failure of equipment to function as intended. This definition encapsulates any instance where a tool, weapon, or machinery does not operate according to its design specifications or expected performance. Malfunctions can occur due to various reasons, such as mechanical failure, user error, or manufacturing defects, and identifying this definition is critical in a range setting to ensure safety and effectiveness in operations.

In contrast, the other choices do not align with the standard definition of a malfunction. An unexpected success of an operation doesn't pertain to failures but rather indicates an achievement or outcome beyond expectations. Interruption due to environmental conditions refers to external factors affecting operations rather than the failure of equipment itself. Lastly, a routine maintenance check is a proactive measure performed to ensure that equipment remains functional, rather than a definition of what constitutes a malfunction.