Internal benchmarking in the service of improving business processes, and the business success of the company, became an instrument and a necessity in complex companies where there is the possibility of comparison of similar parts of the whole. The result of the process of benchmarking is finally learning from the best, behavior change and continuous improvement (of the product, process, function). Given the relative ease of implementation of internal benchmarking, availability of data and information within the system, internal benchmarking can become an instrument of permanent improvement in the operation of complex business systems. HEP Distribution System Operator is a company in which a comparison is possible due to the company's organizational structure with decentralized organizational units that are mutually comparable, have similar or the same organizational structure, similarly defined business processes, but they are different to the organization of business activities within the process, the level of development of business processes and the quality of work organization. Functions, business results, costs and processes can be compared, and such comparisons produce a certain conclusion. To improve any object is not sufficient comparison. There arises a need for a method which would use possibility for comparison in achieving improvements. Benchmarking provides a great opportunity to achieve improvements, so in a situation when in a large system there are comparable processes, the idea of usefulness of internal benchmarking process occurs, which can result in a significant effect in improving business processes. By applying the method of internal benchmarking, one can identify their own place within the system, the ambition to improve is encouraged and learning from the better causes the change of positions, inspires becoming the best. Improvements are only possible with the application of knowledge and continuous repeating of benchmarking process cycle, similarly to the learning process.