If the ranking of students is based on grade scores independent of the selected college or university, it is critical to have an equal national measurement standard. It is a challenge to ensure this if there is a substantial difference in the composition of the students and enrolment requirements among colleges. Based on three different types of colleges in Norway merged into one unit in 2019, this paper examines the grading practices before and after the fusion. By using a regression model to predict the grade depending upon students' academic skills, one can identify different grading practices for the three independent schools and compare the results after they become one unit with identical exams and a common evaluation. The results show significantly more lenient grading practices at small colleges with low entry criteria and that the evaluation is more random, depending upon the instructor. Furthermore, this paper confirms that the grade point average (GPA) from upper secondary school, mathematical abilities and gender are strongly correlated with success in business studies.