Associated risks with this method are: Low forecast accuracy and numbers of planners required. There are various software systems created by companies such as Dynasys, Avercast, Demand Solutions, RightChain TM, SAS System, Agentrics, Manugistics, Oracle, Petrolsoft Corporation (now Aspen Technology), StatSoft, ToolsGroup and GMDH Shell that are designed to forecast demand and plan operations. To test the added value of implementing bottom-up approach, SAP APO applications are providing simulations functionalities to estimate the resulting Demand Forecast Accuracy (e.g. POS sales ; Sales invoices ; shipments, etc.)