A provisionary period, as used in the personnel policies of an employment manual, works to define the fact that the individual is in employment of the company on a trial basis. During that provisionary period, an individual may be fired either as a result of a set list of specified conditions detailed within the manual, or in cases of at will employment states, for any reason at all, up to and including the belief on the part of the company that the individual is simply not a good fit for the company.
The provisionary period, while it may at first appear as though it is designed only with the employer in mind, works to benefit the employee as well. If the employee decides that he or she is not a good fit with the company, if he or she does not like his or her boss, or if he or she feels as though the job is not something that he or she wants to do after being shown what the job entails, perhaps being different from how he or she pictured it in his or her head, the individual likewise has the option of walking away. This provision likewise works in favor of the employee as gives the employee time to adjust to learning the tasks that he or she will need in order to complete a given job, allows for time for improvement, and works to ensure that the individual has all the training that he or she needs without fear of immediate repercussions.

The provisionary period is typically concluded after three to six months, depending on the position, size of the company, and job duties of the individual and is generally followed up by a performance review. The results of that performance review allow both parties to decide if the position is a good fit for the individual and a good fit for the company. In conclusion, the use of such a policy works to make a healthier work environment for all parties.