Planning production space: Why buffer zones are crucial to success
Avoid the most common planning mistake: without buffer zones for WIP and materials, production comes to a standstill. A guide to efficient space utilisation.
When planning a new production facility or leasing an industrial hall, everything starts with a layout plan. Machines are drawn as rectangles, aisles are marked – and on paper, everything seems to fit perfectly. However, the reality after moving in often looks different: pallets block walkways, employees constantly have to rearrange semi-finished products to get to material, and the forklift barely has room to turn.
The reason for this chaos is a common planning error: the focus is too heavily on the pure "footprint" of the system, i.e., the area physically covered by the machine. What is forgotten is that production consists not only of the processing itself but equally of internal logistics. A machine must be able to "breathe." This means it requires defined zones for the inflow, temporary storage, and outflow of material. These so-called buffer zones are not wasted rent but a prerequisite for a smooth value creation process.
Zone 1: Input – Where Material Awaits
Every manufacturing process begins with raw material. Even if you work according to strict "Just-in-Time" principles, every system requires an operational supply directly at the workstation. The machine operator should not have to walk to the central warehouse for every component.
This is where Kanban shelves or pallet spaces come into play. When planning your space, ask yourself: How is the material delivered? Does it arrive on Euro pallets, in wire mesh boxes, or as long goods? A single Euro pallet space (0.96m²) quickly requires two to three square meters of actual area, including the necessary handling space. If you process two different raw materials, this requirement doubles. If this defined space is missing, the material stands in the aisle – a classic safety risk and a violation of SUVA (Swiss National Accident Insurance Fund) guidelines regarding clear escape routes.
Zone 2: Work in Progress (WIP) – The Underestimated Space Hog
Perhaps the most frequently underestimated volume in a production hall is the so-called "semi-finished goods" or "Work in Progress" (WIP). In an ideal world, a part from process step A flows seamlessly to process step B. In reality, there are cycle time differences. If machine A produces faster than machine B can process, a bottleneck occurs.
These semi-finished parts must be stored somewhere. Even more critical is the space requirement for physically determined waiting times. Do glued parts need to cure? Do welded components need to cool down before they can be measured or further processed? This "maturation process" requires buffer areas that belong neither to storage nor to the machine but form their own zone. If this requirement is underestimated, expensive production areas quickly become improvised storage rooms, drastically reducing the efficiency of the entire line.
Zone 3: Output and Quality Control
When the part leaves the machine, it is often not yet ready for shipment. In modern production lines, quality assurance (QA) often takes place directly at the machine ("Quality at the Source"). This means you need space for an inspection table, measuring devices, and separate containers for "good parts" and "rejects."
In addition, the finished goods must be transported away. The same logic applies here as with input: when the forklift driver picks up the finished pallet, they need maneuvering space. A forklift, depending on the model, requires an aisle width of 3 to 4 meters to safely pick up a pallet without bumping into shelves or machines. These traffic areas are included in the rental price but must be kept clear operationally.
The Rule of Thumb for Space Planning
So, how much space do you really need? Experts in factory planning and work organization (e.g., according to REFA methodology) warn against calculating too tightly. A proven rule of thumb states: the pure machine footprint should be multiplied by a factor of 2.5 to 3 to determine the actual space requirement, including operation, maintenance, material buffers, and traffic routes.
A 10m² CNC machine therefore actually requires closer to 30m² of hall space to be operated productively. Those who save here save at the wrong end. The cost of an additional square meter of rent is usually significantly less than the personnel costs incurred by inefficient processes, search times, and constant rearrangement of material.
Conclusion: Space is a Production Factor
View the rental space not just as a cost block but as a production tool. A hall that offers enough space for buffer zones and a clear separation of value creation and logistics pays for itself through higher process speed and occupational safety. Therefore, when viewing potential production areas, do not just focus on whether the machine fits, but whether it can also operate efficiently there.