Mergers and acquisitions often fail to generate the expected value. One of the main reasons for such failures is a lack of cooperation among employees which prevents the expected formation of synergies. Florian Frensch investigates which individual characteristics of employees and which dyadic factors of relationship partners affect the cooperation between employees of previously separated firms. The author develops an innovative approach for gathering network data with the help of a dynamic computer-based questionnaire which allows him to conduct a full network analysis of a group of approximately 400 employees on the lower operative level of the firms. He shows that structural cooperation requirements and integration measures are powerful means to make employees cooperate after M&A and provides answers to the questions how integration after M&A can be measured, explained and improved.