A brand identity requires much consumer research and collaboration with your creative agency in its construction and refinement over time. Start off with consumer studies, and identify consumer segments that is lucrative enough, and that you can win in.
Have classic models like differentiation, portfolio architecture, credibility supports, and benefits (functional, emotional, and experiential). It is a very detailed final model, and you must treat the brand just like an asset or employee of the company. The brand provides value, and has its distinct personality. The brand team is just like the pit stop team mates in a formula one race, and the brand, the formula one driver/car.
The next part is to understand how consumers perceive your brand vs. how you will like it to be positioned. If there is a difference, you have a gap you need to fill. If your brand is positioned for the younger people, but ended up being purchased by mainly the older folks, you have to find out why your brand is unappealing to the younger audiences.
Also, if your benefits are not clear to consumers, your advertisement either has confusing statements, insufficient investment or has too many messages that confuse the consumers. Simplify to just 1 message, or at the very, very most, 2 messages on benefits of your brands. Too many messages dilute the strength of the messages.