The 2021-2023 shortage taught everyone to hold more stock, but stock solves quantity, not origin. The real exposure is a part number with only one viable channel: when allocation policy or distributor flow changes, the line simply stops.
Dual sourcing is not just buying the same part from two suppliers. A workable structure has three layers: two manufacturer brands (functionally compatible, needs light validation); one brand through two channels (franchised plus independent, as a lead-time backstop); and design-level alternates (board or firmware change, highest cost but most robust).
Put all three layers into the BOM review at project kickoff, especially for MCUs, power management, interface devices and memory. That middle layer is where an independent distributor earns its place: filling the gap between factory lead time and production with stock and in-transit material, plus a verifiable list of alternates.