Bedarfsermittlung
Also: Materialbedarfsermittlung, Bedarfsplanung, Mengenplanung, Bedarfsrechnung, Bedarfsprognose
AI-generated
Requirements planning refers to the systematic process by which an organization's future material or goods requirements are determined in terms of quantity and timing. It forms the basis for inventory management, procurement, and warehouse planning.
Key facts
- Requirements planning determines which materials or goods need to be procured, in what quantities, and at what point in time.
- A distinction is made between deterministic planning based on orders or bills of materials and stochastic planning based on consumption history.
- The quality of input data – item master records, inventory levels, bills of materials – is critical for reliable demand figures.
- The choice of planning method should be guided by item classification (e.g., ABC analysis) and demand volatility.
What is requirements planning?
Requirements planning is the structured determination of which materials, goods, or components are needed, when they are needed, and in what quantities. It stands at the beginning of every planning cycle in procurement and production: without reliable demand figures, neither inventory levels can be sized meaningfully nor delivery dates agreed upon with suppliers. Requirements planning is therefore a central link between sales planning, production, and purchasing.
Methods at a glance
In principle, two approaches are distinguished, which are often combined in practice:
- Deterministic requirements planning: Demand is derived directly from existing orders or production plans – for example, via bills of materials in an ERP system. This method is precise but requires a stable order situation.
- Stochastic (forecast-based) requirements planning: Here, historical consumption data is statistically analyzed to estimate future demand. Common methods include moving averages, exponential smoothing, or seasonal models. This approach is particularly useful when there is no fixed order intake, such as in spare parts management or the consumer goods sector.
In addition, there is rule-based or heuristic requirements planning, which incorporates empirical values and manual assessments – for example, for new items without historical data or following market changes that render historical values obsolete.
Requirements planning in practice
In modern warehouse management and ERP systems, requirements planning runs largely in an automated fashion. Planners define planning parameters – planning horizon, safety stock, lot size – and the system calculates the net requirement on that basis, meaning the actual procurement requirement after deducting available stock and orders already initiated.
The quality of the input data is critical: incorrect master data, unposted goods receipts, or outdated bills of materials lead directly to shortfalls or excess inventory. For this reason, requirements planning is closely linked to master data maintenance and effective inventory management.
What to look for when choosing a method
The choice of method depends significantly on the item structure. An ABC analysis helps to plan high-value A-items deterministically, while C-items can be managed with simpler forecasting models. For volatile demand or long lead times, safety stocks and rolling planning cycles are particularly important. Systems that combine both methods and can respond automatically to deviations significantly reduce manual effort – however, this also increases the complexity of parameterization.
Related terms
- ABC-Analyse
ABC analysis is a method for classifying items, vendors, or processes into three priority classes (A, B, C) based on their economic significance. It forms the basis for differentiated decision-making in warehousing, inventory management, and procurement.
- Absatzplanung
Sales planning refers to the systematic forecasting of future sales volumes for defined products, regions, or channels. It forms the foundation for all downstream planning processes in production, procurement, and logistics.
- Absatzprognose
The sales forecast estimates future demand for products or items over a defined period. It forms the basis for inventory, capacity, and procurement planning in logistics and purchasing.
- Artikelstammdaten
Item master data refers to the permanently valid base data of an item – such as dimensions, weight, packaging units, hazardous goods classification, and best-before date relevance. It forms the foundation for all logistical, procurement-related, and system-driven processes along the supply chain.