What is the most important step in a machine learning project?

The CRISP-DM is a common standard for machine-learning projects. All these six steps of a machine-learning project are crucial. Quality issues in each step will directly affect the quality of the entire outcome. However, advising to many organizations on machine learning, and running even more such projects ourselves, we (at YellowRoad) came to a conclusion, that the most under-invested step in the process is Business Understanding. We see many companies discussing algorithms and technology, before understanding the business aspects of the task that they are solving.