A seniority-based right or benefit is one that accrues with, or is determined by, longevity in employment. Generally, whether a right or benefit is seniority-based depends on three factors:

(a) Whether the right or benefit is a reward for length of service rather than a form of short-term compensation for work performed;

(b) Whether it is reasonably certain that the employee would have received the right or benefit if he or she had remained continuously employed during the period of service; and,

(c) Whether it is the employer's actual custom or practice to provide or withhold the right or benefit as a reward for length of service. Provisions of an employment contract or policies in the employee handbook are not controlling if the employer's actual custom or practice is different from what is written in the contract or handbook.