In this article he was able to calculate what a person should do to avoid being obsolete. Charette wrote: “Jones posited that a typical undergraduate engineer invested about 40 hours per week of study for 120 weeks into their degree…Jones stated that about 2,400 hours of undergraduate knowledge were likely replaced …an engineer would have to spend 5 hours each. [week] acquire new technologies, mathematics and scientific knowledge… to stay up to date. (Charette). This is where lifelong learning would come in. Keeping your mind sharp and keeping up with technological "upgrading", as it is called, is one way to ensure that you won't be left behind aside for someone younger than you in the workplace. Engineering isn't the only profession that fears becoming obsolete; Doctors, psychologists and even philosophers have this fear of becoming obsolete within their profession.