Mengenplanung Definition
Also: Bedarfsmengenplanung, Mengenbedarfsplanung, Quantity Planning, Mengendisposition
AI-generated
Quantity planning refers to the systematic determination of how much material, components, or products need to be required, procured, produced, or made available within a defined time period. It forms the basis for demand management, purchasing, and warehouse capacity planning.
Key facts
- Quantity planning determines net material and product requirements by reconciling forecasts, open order backlogs, and existing inventory levels.
- Planning granularity — whether by SKU, week, or month — must be aligned with the industry, product range complexity, and system landscape.
- Inaccurate forecasts have a direct impact on safety stocks, warehousing costs, and delivery performance.
- Both warehouse capacity planning and supplier negotiations depend on reliable quantity frameworks.
Quantity planning is a central element of supply chain management: it defines how much of a given item must be available at a specific time and location. Demand signals — such as those from sales planning, open order backlogs, or seasonal forecasts — are reconciled against existing stock levels, bills of materials, and supplier capacities.
How quantity planning works in practice
The starting point is typically the sales plan or a production program. Component requirements are then derived from this through bill-of-materials explosion. Current inventory levels, open purchase orders, and planned receipts are factored in simultaneously to determine net requirements. These net requirements form the basis for purchase order proposals, production orders, or delivery call-offs to suppliers.
Typical planning dimensions include:
- Granularity: Whether planning is done on a weekly, monthly, or daily basis depends heavily on the industry and product complexity.
- Planning horizon: Short-term operational planning (weeks) and medium-term tactical planning (months) require different levels of data quality and different systems.
- Safety stock: The economically appropriate buffer quantity is calculated on a vendor- and company-specific basis; blanket rules do not exist.
Relevance for logistics and purchasing
For logistics, quantity planning determines which warehouse capacities, conveyor throughputs, and transport volumes need to be scheduled. Overly optimistic planning leads to idle capacity, while overly conservative planning results in overload and delivery delays.
In purchasing, quantity frameworks are the foundation for framework agreements, capacity coordination with suppliers, and volume discount negotiations. Suppliers need reliable forecast quantities to plan their own operations — unreliable planning data degrades delivery performance and drives up costs on both sides.
Key considerations when selecting tools
Quantity planning can be carried out in ERP systems, dedicated advanced planning systems, or even spreadsheet-based tools. The critical factor is how well the solution synchronizes with current inventory data and sales signals. Systems with automatic exception management help identify deviations between plan and actuals at an early stage. Whether an integrated suite or a specialized planning solution is more appropriate depends on the complexity of the product range, the number of planning levels, and the existing IT landscape — no blanket recommendation can be made here.
Related terms
- 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.
- Bedarfsermittlung
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.
- Bedarfsmenge
The demand quantity refers to the quantity of an item required at a specific point in time or within a planning period. It forms the basis for ordering decisions, inventory planning, and production planning.
- Bedarfsplanung
Demand planning refers to the systematic process by which a company determines what quantities of materials, goods, or resources are needed and when. It forms the foundation for inventory management, procurement, and warehouse planning.
- Beschaffungsplanung
Procurement planning refers to the process by which a company systematically determines which materials or goods need to be sourced, in what quantities, at what time, and from which suppliers.
- Bestandscontrolling
Inventory controlling refers to the systematic monitoring, analysis, and management of stock levels using defined key performance indicators. It connects logistics and procurement to reduce tied-up capital and ensure delivery capability.
- Bestandsmanagement
Inventory management refers to the systematic planning, control, and monitoring of stock levels across the entire supply chain. The goal is to ensure delivery capability while keeping capital commitment and warehousing costs within economically viable limits.
- Bestellpunktverfahren
The reorder point method is a replenishment procedure in which an order is automatically triggered as soon as the current stock level falls below a predefined reorder point.
- Disposition
Disposition refers to the operational planning and control of resources, quantities, and orders in logistics – for example in transport or materials disposition. It encompasses capacity assignment, scheduling, prioritization, and response to disruptions.
- Dispositionssoftware
Dispatching software is a software solution for the operational planning, control, and optimization of transports, routes, and resources in logistics. It helps dispatchers efficiently coordinate orders, capacities, and time windows.