APPLICATION NOTE
When Your Component Is Unavailable:
Alternates, Last Buys, and Counterfeits
You receive an allocation notice. A 32-week lead time. An End-of-Life announcement with a
last-time buy window closing in 90 days. What you do in the next few hours determines
whether your product ships on schedule, whether your BOM is going to cost significantly
more, and whether your design needs to change.
This guide covers how to qualify an alternate part in a way that holds up in production, how to
ration available stock when you cannot get enough, how to make the last time buy versus
redesign call with the right inputs, and how to assess counterfeit risk when allocation
pressure pushes you toward non-standard sources.
None of these decisions are as simple as the standard guidance suggests. This guide covers
the hard cases.
WHAT THIS GUIDE COVERS
1. Qualifying an alternate component: form-fit-function gaps, the requalification decision, and
what to do when no alternate exists
2. Partial availability and rationing: how to allocate constrained stock across competing programs
3. The last time buy decision: how to calculate the right quantity, what it actually costs to hold
inventory, and when redesign is cheaper
4. Counterfeit risk: which component categories are most targeted, what non-destructive testing
can and cannot detect, and how to evaluate a non-authorized source when allocation forces the
issue
