Companies are confronted with an increasingly dynamic and complex environment, facing constant market changes that are relevant to competition. To maintain their competitiveness, it is necessary to preserve, expand, or develop new success potentials. Synergy-oriented mergers and acquisitions (M&A) are considered an important strategic alternative for tapping into or preserving competitive success potentials. However, due to insufficient and unsystematic synergy planning, realization, and control, a significant portion of the transactions conducted fails to achieve the expected synergy effects, and the goal of increasing corporate value is often missed. To counteract this deficit, a synergy controlling system must be established, which supports management by accompanying the M&A process with a focus on synergies.