The original iPod went from idea to finished product in just 10 months

iPod. Tony Fadell was hired to create the iPod in late January 2001. Steve Jobs greenlit the project in March 2001. They hired a contract manufacturer in April 2001, announced the product in October 2001, and shipped the first production iPod to customers in November 2001, around 290 days after getting started. Source: Tony Fadell.