or, at least on the screen- is “My life and work” the autobiography of Henry Ford. An excerpt, that any good businessman will understand:

The principal part of a chisel is the cutting edge. If there is a single principle on which our business rests it is that. It makes no difference how finely made a chisel is or what splendid steel it has in it or how well it is forged–if it has no cutting edge it is not a chisel. It is just a piece of metal.

Ford, Henry (2009-10-04). My Life and Work (Kindle Locations 230-232). Public Domain Books. Kindle Edition.

You should ought to read this, if you do any kind of a business, or strive to.