Effective quality management is a factor that determines the development of a company. Quality management measures include quality planning, quality control, quality assurance and quality improvement. The aim of the research was to diagnose the condition of a cable well at quality control points and to precisely define the reasons why appropriate preventive measures could significantly contribute to the reduction of the number of non-compliant products. Additionally, the aim was to propose a sequence of actions supporting the analysis of production problems (occurrence of incompatibilities in the tested product). Due to the growing number of complaints in the company and the lack of analysis of the causes of the situation. Sequences of quality management methods were applied, thanks to which inconsistencies occurring in products were classified in terms of their significance and frequency of occurrence (Pareto-Lorenza diagram). Additionally, the analysis of the reasons for non-compliance was performed (method 5Why?). The most important inconsistency in the tested product are cracks in the bottom part of the product, which is caused by low qualifications of the employees.