Absenteeism is a result of multiple factors. The best thing to do before taking any action towards attempting to resolve the issue is to first understand it.

Some basic analysis of the issue should help identify some trends, for example what are the most common days people are taking off. Do those days correlate with any internal or external events. If you can see a trend appearing, for example every second pay day the same employee is calling in sick, you can start to understand what is happening.

People are creatures of habit, that is why behavioral modeling is so effective if done correctly. If you have a system in place to identify when employees are starting work you may even be able to identify early signs of absenteeism and address the issue before it starts.

Absenteeism reporting is common place in large businesses, sure they have expensive reporting software however the same analysis can be done without expensive software.

In some cases it could simply be the person is lazy however in a lot of cases it is something you need to do to change. Like Neil said in his reply, review internal factors as it could be something your doing. KPI, bonus structure and other incentives work however some people just need a challenge and may be getting bored with their job and seeking new challenges.

In my experience recurrent problems such as absenteeism suggest underlying management issues within the organisation. These problems can result from a single bad manager or a more fundamental problem with your organisational structure, poor recruiting practices or your levels of staff engagement and communication.

The first step is to question why (assuming it is organisational absenteeism rather than a single person) staff are dissatisfied and feel the need to take time off, look firstly within for a possible solution.

If it is a single person absenting themselves repeatedly, firstly look at their work environment and line manager and if all looks good there discuss the issue with the staff member, do they have problems outside work, can you help, would greater flexibility in working hours help? Of course if the person is simply a shirker then move to terminate that person with due process.