I thought the standard for software engineering projects was to take the estimate, bump up a unit and multiply by 2: 1 hour --> 2 days 1 week --> 2 months

I thought the standard for software engineering projects was to take the estimate, bump up a unit and multiply by 2: 1 hour --> 2 days 1 week --> 2 months . . . so 10 years would have been 20 decades :)