Post-merger integration or PMI is a complex process of combining and rearranging businesses to materialize potential efficiencies and synergies that usually motivate mergers and acquisitions. The PMI is a critical aspect of mergers; it involves combining the original socio-technical systems of the merging organizations into one newly combined system.

The process of combining two or more organizations into a single organization involves several organizational systems, such as assets, people, resources, tasks, and the supporting information technology. The process of combining these systems is known as 'integration'. Integration Planning is one of the most challenging areas to address pre-close during a merger or acquisition.

Common problems that may be encountered during post merger integrations include resistance to change, divided loyalties, blurred roles and responsibilities, unclear reporting relationships, communication tangles, job insecurity, unusual employee turnover, and infighting. 

In the context of post-merger integrations, organizational network analysis (ONA) can help companies accelerate and increase the adoption of the different strategic changes that need to be implemented by positioning informal leaders as early adopters.

Figure 1: Organizational Network Analysis implemented in a Post-Merger Integration

Moreover, once the post-merger integration has been completed, ONA can help companies measure the effectiveness of the integration by analyzing whether the employees are sticking to their previous connections on the legacy organizations or they are creating additional connections in the new organizational structure. The level of integration between teams is compared against performance metrics at department level, thus providing a framework to measure the impact of the integration on the organization's performance and helping the company identify opportunities for improvement.