This white paper summarizes the key to solving problems related to SI project income/expense management, specific examples of management screens, and a case study of a major SIer that has actually revamped its system with an eye to diversifying its services. For PMO/development management staff who want to reduce the burden of project balance management for development PMs, and for purchasing staff who want to streamline transaction management with partner companies/subcontractors, please read this paper as a clue to solving your issues.