Write out and/or diagram simple instructions for your product.
- If the instructions take more than three steps, your product isn't usable; redesign it.
- If the instructions don't actually match your product, quit smoking the good stuff on company time and write/diagram them again.
- If users need both the written instructions AND the diagrams, then the product is more-or-less usable, but not user-friendly.
- If users need the written instructions OR the diagrams but not both, then the product is somewhat user-friendly, but not sufficiently so as to justify entitling the instructions with "For easy operation".
- If users don't need any instructions, THEN the product is user-friendly.