The thesis examines the subject of employees' eventual underachievement in their workperformance. The interests of the employee and the employer will be set against eachother. How poor must the employee's performance be to risk a dismissal and what factorscan contribute? Before the possible dismissal, the essay will also examine whatobligations the employer has towards the employee.The used method is the legal dogmatic method consisting of preparatory work and courtdecisions when underachievement is not statutory in the Swedish legislation. Whatemerges from the legal investigation is that there is a difficulty to get a one-sided pictureof the different obligations and requirements of both parties when each case is veryindividual. In summary, the various factors for an employee to risk dismissal consist ofunwillingness or inability to follow the employer's instructions, work too slowly or poorlyand whether the poor performance is permanent or not. The employer's obligations can besummarized as be obliged to move the employee to another position, point out thecriticism through a warning, develop skills and perhaps the most important part, be ableto document and prove the claim of both parties.

An employee’s job performance does not necessarily decrease just because the employee gets older. But there is an anticipated correlation between reduced job performance and age with respect to certain job assignments. Along with an increased life expectancy in today’s society it’s important to promote equal opportunities regardless of age. The purpose of this thesis is to clarify under witch circumstances a dismissal due to insufficient work performance is justified. Furthermore this thesis purpose is to clarify how current legislation affects elderly’s position on the Swedish labour market when it comes to dismissal due to insufficient work performance. Even though Swedish and EU provision protect senior employees rights to some extent, there are still gaps in the legislation that can disfavour elderly´s possibilities to maintain their employment. In order to answer the research questions at issue a traditional legal dogmatic method is applied in combination with a sociological law perspective.