People are absent from work for 3 main reasons.
On average, in relation to unauthorised absence, people are absent from work for 7.6 days a year (CIPD Absence Survey 2013). Absence management problems often means tackling possible causes of absence, such as working patterns, job design and employment relations. This can also include addressing discipline problems such as lateness and poor time keeping. If such issues should arise, they can often be dealt with informally by the line manager in the first instance.
Unauthorised absence is normally the "odd day off" when employees give no reason for the absence. Whether paid or unpaid this type of absence can be costly to an organisation as it is unpredictable. Absence of this kind may eventually lead to disciplinary action.