I'm not particularly bothered at exactly how it gets implemented, just as long as there is a decent way of finding out. Personally I'd put it as extra information in the planet scan - the usefulness of this scan has dropped badly since people hide their resources in production instead of being visible on the planet scan.
Other threads which discuss the same issues as this thread are
Hidden production and value and
Cov-op: Production espionage. I'm still slightly bothered at the fact you can manipulate your value by leaving days worth of resources in production - I hope this issue eventually gets addressed as well.