Management decision making requires accounting information.
The management process is a series of activities in a cycle of planning and control. Planning involves decision making - the purposeful choice from among a set of alternative courses of action designed to achieve some objective. Control also involves decision to plan a control action. The difference between planning and control decisions is planning is more open ended with less constraints. Control is a more constrained process in which the main objective is achievement of plans and the main input is actual results in a period and comparison of them with the planned results.
Management accounting formalizes plans of the organization as budgets. It also formalizes the control process by preparing as performance reports.