The standard specifies a test amplitude sufficiently large within the selected frequency range to achieve a reasonably high degree of confidence that the equipment will not fail during service operations. To achieve this, engineers conduct and endurance testing procedures that identify natural frequency response prominences. These response peaks represent frequencies at which equipment is most vulnerable to vibration damage.
Engines and other systems with repeating motion. mil-std-167-2a pdf
The family serves as the foundational architecture for managing these stresses. However, it is explicitly split into two complementary standards to address different types of excitation: MIL-STD-167-1 vs. MIL-STD-167-2 The standard specifies a test amplitude sufficiently large