The Third One Is Creating a Product Specification Document

Document helps you to batch the communication and avoid ambiguity amongst all your stakeholders. Not having a speck might work for a small feature or a small set up, because there are fewer moving parts over there. But it would not work, or it is most likely not going to work, for a mature form or a mature product where there are lots of moving parts. And not having a document where everything is documented with clarity can only lead to a lot of confusion.