INGENIEURBÜRO HAHN is led by Klaus and Sebastian Hahn. The two bring in versatile and long-term experience from different backgrounds and combine technical know-how with commercial expertise to form an overall effective package. 

Klaus Hahn

Industrial engineer


• Management systems

• Professional certifications

• Certification audits

• Reorganization

• Process management

• Trainings



Klaus Hahn is an industrial engineer and a longtime freelance business consultant in organization and process consulting. His consulting focus lies in the implementation of integrated management systems as well as professional certifications in compliance with national and international standards.

He therefore performs all kinds of system and process audits e.g., internal audits, supplier or accredited certification audits, etc. and also helps develop your staff with respect to the requirements of management systems. With his extensive expertise and long years of experience, Klaus Hahn is also a specialist in reorganization and process management. 



Before founding INGENIEURBÜRO HAHN in 1999, Klaus Hahn was responsible for the design, implementation and practical realization of quality and occupational safety management systems in a group of companies in the construction industry.

During this time, he became a qualified quality control manager/auditor, environmental systems auditor, and specialist in occupational safety. He later moved on to serve as a commercial manager in a medium-sized company. While working as a consultant, he was able to expand his know-how and prowess through different trainings. Among other things, he became a qualified business mediator and IHK rating advisor. Additional trainings in quality management, environmental protection, performance indicator systems as well as occupational safety and health management add to his competence. In addition to consultation, he also worked at DNV GL for 18 years as a leading certification auditor for quality and occupational safety management systems and, on customers’ requests, also assists companies in safety-related maintenance as stipulated by the Occupational Safety Act.

Sebastian Hahn

Business administration specialist


• Operational restructuring

• Process management

• Reorganization

• Management systems

 • Workshops




Sebastian Hahn studied business administration and has been working as a business consultant for several years. In addition to development of different management systems, he also specializes in the development and implementation of operational restructuring measures as well as conducting optimization projects for structural and process organization. This includes assimilation and optimization of business processes as well as the establishment of a wide range of management and control instruments. He also performs organizational-based maturity analyses, develops controlling tools, and helps in implementation of quality methods. In addition, he also designs and chairs various workshops that focus on the handling of different tasks. 



After six years of working for Ernst & Young, a global consulting and auditing company, Sebastian Hahn has been a reinforcement to INGENIEURBÜRO HAHN since late 2013. As part of an international trainee program at the beginning of his career, he worked in the auditing sector and was involved in the auditing of both single and consolidated financial statements as stipulated by German and international accounting standards. Here, he also took records, documented and made reviews of different business processes.  After his work in auditing, Sebastian Hahn switched to operational transaction consulting and has assisted clients from all around Europe with international carve-outs, post-merger integrations, and operational restructuring. Since his time at INGENIEURBÜRO HAHN, he has, among other things, been adding to his expertise as a quality manager and internal auditor.