In the context of engineering studies, and specifically in courses related to manufacturing processes, student must solve practical problems by applying a high variety of knowledge and skills that should have been acquired from previous courses, such as statistics, geometrical and dimensional tolerancing, physics, materials and metallurgy, mathematics, etc. Therefore, it can be expected that the degree of assimilation and retention of knowledge reached at these first-year courses has a relevant influence on the students’ performance in later manufacturing courses. In this sense, during last years the authors have identified many errors in the students’ tests due to the deficient assimilation of basic concepts from previous courses, such as physical concepts (torque, power, energy, etc.) or mathematical concepts (inequalities, use of exponential functions and logarithms, trigonometry, properties of statistical distributions, etc.), among others. In this work, the students’ performance in manufacturing courses and the relationship with their competences in mathematics acquired in previous years are analyzed. For this purpose, the students’ background on these fundamental previous courses is analyzed through a test at the beginning of the semester. The study will be conducted on third-year courses in mechanical engineering, industrial engineering, and industrial design engineering degrees.