One of the tactical advantages of targeting corporations is that they often actually publicize and explain their own systems and vulnerabilities in their own corporate literature and information packages for investors.
Whenever a company proclaims the unique aspects of its operations that make it particularly efficient and profitable; that is a vulnerable point. It is a key component of their system which, if disabled, will cause intolerable disruption.
Useful information can also be found in the job advertisements for multinational companies. The salary, educational and work experience requirements, and descriptions of tasks and responsibilities; all of this will provide important insights into the internal system of a company, and its most vital components.