Generally, a patent can remain in force for twenty years from the date of filing. This fact is sometimes lost on inventors.
An invention should be described in a patent within the context of the patent’s useful life. For example, if an invention works with some kind of computing device, the computing device should be described in rather generic terms. This is because we do not know what kind of computing devices there might be in the future. Will the invention work with different computing devices that might be developed 15 years from now? If so, it would be foolish to limit the invention to only the computers we know today.
Unless the patent author specifically thinks about future embodiments of the invention, and discusses these embodiments with the inventor and the business manager, certain coverage may be lost in the patent. These discussions do not have to be long and arduous, and the results can be woven into the specification of the patent and, most importantly, into the claims.