Starships named Enterprise have been notorious in this regard. Granted, some of these points were retcons, but that doesn't excuse anything. It's all canon.
NX-01 - 2153-2161 (8 years): The ONLY reason why the ship was decommissioned was so that it wouldn't be a Federation starship, as the NCC-1701 has canonically been the first. There's no other logical reason why it would have been scrapped. And why did Starfleet wait 80 years before naming another starship the Enterprise?
That, or because of creation of the Federation, and merging 4 different species science and technology into one may have resulted in the NX-01 being decomissioned earlier.
On the other hand, PIC Season 2 does have the NX-01 refit as a model on showcase in the Picard mansion while Jean Luc was just a kid.
This could imply that the NX-01 may have been decomissioned, but, it could have been recomissioned and upgraded with the secondary hull addition to extend its service.
If that happened, it could have been in active service for 80-83 odd years.
NCC-1701 - 2245-2285 (40 years): Despite Morrow's idiotic comment that the Enterprise is 20 years old, Starfleet is ready to decommission a perfectly good ship (and a refit one at that); its only problems being that it came under attack by Khan.
Pretty much... but then Kirk also blew it up.
NCC-1701-A - 2286-2293 (7 years): Nothing has ever been canonically stated or shown that the Enterprise-A was anything other than a brand-new vessel as of 2286, which makes its decommissioning only 7 years later even more mind-boggling than the NX-01.
That it does. Its possible that SF was adamant about replacing the Constitution class with the Excelsior class ships though, hence the ENT-B.
NCC-1701-B - 2293-?: Sometime between 2293 and 2344 (51 years), the Enterprise-B must have been decommissioned or destroyed. But even if the B was in service for, say, 25 years out of those 51, its replacement with the Ambassador class Ent-C makes no logical sense. There are literally tons of Excelsiors still active in the TNG era. Why would the B have been decommissioned at all if this were the case? And if it was destroyed, why didn't they just replace it with another Excelsior?
I don't know. Perhaps we can ask someone on Tuesday (tomorrow)?
In all seriousness, its possible SF was in a 'lets replace the old Enterprise with a new class of ships modern to the era'.
It seems to have carried a bit of a 'prestige' in this sense because significant changes in technology occurred which (at the time) might not have been possible to easily install in the Excelsior class.
Maybe there was politicial nonsense going on with the Enterprise 'showing the flag' so to speak... and they may have figured that using the Ambassador class might have been better for this.
NCC-1701-C -?-2344: Ditto above for service history. The C was commissioned some time between 2293 and 2344 (51 years). Why did Starfleet not make the next Enterprise another Excelsior? And instead, why did they make it a relativly obscure class of ship that was barely ever seen, especially in the large DS9 fleet shots, where we mostly saw Excelsiors? And why did Starfleet wait 20 years to build another Enterprise?
Maybe Starfleet wanted a break with the Enterprise ships for a while. Who knows.
We've been shown that SF does some very questionable things at times.
NCC-1701-D - 2363-2371 (8 years): The D was destroyed only 8 years into its service, so we don't know how long it would have lasted otherwise (other than seeing the AGT future where it was decommissioned by 2395 (at least 32 years of service), which is also quite short.
AGT certainly showcased it running in the future... but, it was mentioned in that two parter that Riker had to pull it out of mothballs... so the ship was evidently pulled from active service after about 25-30 odd years.
NCC-1701-E - 2372-?: We can't as yet calculate how long the E lasted, since we don't as yet know the circumstances of its decommissioning/destruction, or when the Enterprise-F is operating.
I would imagine the Enteprise-F was already operating for a few years since PIC season 1 aired.
So, its possible the Ent-E was in service for 25 years (until about 2395) before being decomissioned and replaced with the F.
Seems utterly wasteful. Its as if SF began to replaced the Enterprises with every major change in crewmen (or the captain).
Once the captain and first officer of the ship steps down, the entire ship is decomissioned and a new one give to a new crew.
We know that the Consitution class dates back to before Strange New Worlds... and Pike has been in command of the ship for a while... so the original 1701 seemed to have seen at least several major crewmen changes... but since then, if an old crew retired or moved on, the ENT class followed?
I dunno.
Could be just pure chance that we saw something like this happening. I doubt that the captain of the ENT-B was in command for 51 years.
Possible?
Yes. Likely? Nope. In all likelihood, he would have been promoted long before that happened, and his first officer (whoever that may be at the time) would have taken his place.
