Finding a replacement for an obsolete part
How to define what a replacement must match when the original is discontinued.
Define the interface, not the brand
List what the replacement must match: dimensions, mounting, connections, electrical or mechanical ratings, materials and approvals.
Separate must-match from nice-to-match
Fit and safety ratings are non-negotiable. Colour, brand and minor features usually are not.
Ask suppliers the right questions
Confirm form-fit-function equivalence in writing, and ask for the datasheet of the proposed alternative before ordering.