In the past, there was not a systematic approach to build one business model that will enable you systematically to follow and improve it through the practice.
The best approach to build a business model in a very descriptive way where you will obtain the most important aspects of your business is described throughout the book titled as Business Model Generation – A Handbook for Visionaries, Game Changers, and Challengers from Alexander Osterwalder and Yves Pigneur.
In the book, they define a business model as:
rationale of how an organization creates, delivers and captures value.
Here is the explanation video of the model.