Eff Oh:
I purposely left out the name of the engine mfgr, lest I be accused of "bashing" someone. The fact is, the mfgr miscalculated in this case.
I fly the 747-400 with the CF6-80-C2-B5F engines. They used to be -B1F engines until a new electronic controller plug gizmo was installed in each of them, raising the thrust substantially. All engine mfgrs do it, generally after analysis of the lower-rated engines in operations over a reasonable period. if operational experience validates their engineering analysis, they can extrapolate and uprate the engines.
Now I wish I had saved all the -B1F stuff from the FHB, so I could compare max EGT, N1, and thrust...