M&A Sourcing and Initial Vetting Process

We commonly hear that companies that proactively identify acquisition opportunities, rather than waiting to hear from a banker/broker/advisor, have greater long-term success. Finding a company that is a strategic and financial fit and which has shareholders/executives/boards who believe it is the right time to exit is a difficult task. In my experience, it requires considerable time and resource investment to bring a deal the table.

I would very much like to start a discussion the process for deal sourcing, the workflow for initial vetting and the gating process for entering into an Letter of Agreement or MOU. Who is involved? How many steps are there? Is there a replicable path to success?