Business communication

It is used for negative reports, where an explanation that leads to the negative end is adopted.

Secondly, one must see who it addresses. If it is written to a higher up, it must be written in an indirect approach, since it is generally written in undertone and polite, instead of sounding too direct or bombastic.

Thirdly, the kind of structure to be followed determines the approach to be adopted. If an explanatory and then a conclusive answer is the preferred idea, then the indirect approach is to be adopted. Meanwhile, for a direct statement of the idea, the direct approach is appropriate.
In the mentioned scenario, the direct approach would be a risky one, since it would sound too impolite and direct. The indirect approach would be best suited for the situation.