The Letter π (pi)

When ever you are conducting research and development in any capacity remember that everything takes more time and costs more than you expected. Even with your best educated guess you simply don't know what you don't know. Experienced project leaders and venture capitalists agree on the rule of thumb to multiply time estimates with π (pi~3,142) and divide projected profit with the same constant. If your business case can withstand the π-test your business is likely to be sustainable and robust.