This chapter discusses production environments, forecasting, aggregate planning, master scheduling, requirements and capacity planning, scheduling and production control, material planning, and manufacturing resource planning (MRP). There are four basic production environments to choose from: (1) manufacture-to-stock; (2) assemble-to-order; (3) manufacture-to-order; and (4) engineer-to-order The production and inventory planning process begins with forecasting. Companies typically plan at three levels: (1) long term; (2) intermediate term; and (3) short term. With the completion of the aggregate plan, top-level management authorizes the production- planning department to develop a master production schedule (MPS). After the master production schedule has been formulated, rough-cut capacity planning (requirement planning) is done to determine its feasibility and where bottlenecks will occur. A much more detailed capacity plan can be generated using capacity requirements planning (CRP). There are two general types of material planning, rate-based planning and time phased planning. Manufacturing resource planning (MRPII). It is an accepted approach for planning and scheduling all of the resources that manufacturing companies need.