According to McKinsey, people usually remember one, two, three, but not four, five, six, so everything should be summarized in less than three. This is now widely circulated in the business world "30 seconds elevator theory" or "elevator speech".
Under the performance appraisal system, which is characterized by strengthened accountability, it is not uncommon for superior managers to shirk their responsibilities and let their subordinates bear the consequences of their mistakes.