There are various forms of economic planning that vary based on their specific procedures and approach. The level of centralization or decentralization in decision-making depends on the specific type of planning mechanism employed. In addition, one can distinguish between centralized planning and decentralized planning. An economy primarily based on planning is referred to as a planned economy. In a centrally planned economy, the allocation of resources is determined by a comprehensive plan of production which specifies output requirements. Planning can also take the form of indicative planning within a market-based economy, where the state employs market instruments to induce independent firms to achieve development goals.