Michael L. Fredman co-developed Fibonacci heaps with Robert Tarjan. Their 1987 paper uses deferred restructuring and amortized analysis to obtain constant amortized time for operations including insertion and decrease-key, with logarithmic amortized time for delete-min.[ref]
Fibonacci Heaps and Their Uses in Improved Network Optimization Algorithms by Michael L. Fredman and Robert Endre Tarjan. §§2–3, operations and potential analysis
This matters in graph algorithms that repeatedly lower tentative priorities: reducing the cost of many decrease-key operations can improve a whole algorithm's bound. A single operation can still be expensive. The guarantee concerns the total cost of a sequence, so confusing amortized time with the worst-case analysis of each individual operation loses the point of the construction.
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