Personal level coaching is increasingly being adopted by managers as a corporate training tool. Each such manager must engage in two kinds of coaching. The first one of them is Calendar- driven. This one is formal, structured and can only be initiated by the manager. It is a broad form of coaching where the entire work is reviewed across all aspects, not any particular project or assignment. Such sessions act as a forum for all with proper two-sided feedback. The other form of coaching is Event- driven. As the name suggests, this one is activated whenever there is a requirement around major events or projects. The focus is on particular happenings. Managers try to eradicate specific mistakes which their team members may have committed. Event- driven coaching can be initiated either by the boss or the subordinate.  

Source: https://hbr.org/2016/09/every-manager-needs-to-practice-two-types-of-coaching