Inventory slotting is one of the most effective—yet often overlooked—ways to improve warehouse efficiency. From speeding up picking to optimising space, a good warehouse slotting strategy can deliver major gains in productivity, accuracy, and cost savings.
In this article, we’ll break down what slotting is, why it matters, and how to get started.
Warehouse slotting is the process of strategically organising products in your warehouse to maximise operational efficiency. It involves assigning each SKU a location based on factors including:
– Sales velocity (how fast it sells)
– Product size, weight, or handling needs
– Frequency of orders or co-picks
– Seasonality or promotion schedules
Slotting is the logic behind your warehouse layout—placing products where they’re most useful, not just where there’s space.
It influences how fast your pickers move, how much stock you can hold, and even how accurate your orders are.
Warehouse slotting is more than being organised and tidy—it’s a competitive advantage. Effective slotting delivers:
– Faster Picking: Reduce travel time by placing high-volume SKUs closer to pack zones.
– Higher Accuracy: Logical layouts lead to fewer picking errors.
– Optimised Space Usage: Store more inventory in less space.
– Lower Labour Costs: Less walking = fewer hours.
– Better Throughput: Improve fulfilment speed and customer satisfaction.
Industry research shows that efficient slotting can reduce picking travel time by 30–50%.
ABC slotting is the most widely used method, based on the Pareto principle.
This strategy works well when your SKU demand follows clear velocity trends. It’s easy to understand and implement—especially when automated using software. Affinity slotting is often used alongside ABC slotting. This is where the products that are often ordered alongside your highest turnover SKUs are stored nearby to optimise the storage and pick process even more.
Each SKU has a dedicated location. It’s simple and ideal for stable inventories or easily trained pickers. However, it can waste space if stock levels fluctuate.
SKUs are stored wherever space is available, tracked by software. Random slotting can dramatically improve space utilisation but depends on strong location tracking and real-time systems.
A hybrid approach is often used with fixed slotting for fast-movers and random slotting for the rest.
Slotting software uses real-time inventory and sales data to automate and optimise product placement. In this way slotting becomes a continuous improvement process reflecting the most recent product demand.
Key features include:
– ABC classification based on velocity data
– Slotting simulations to visualise layout impact
– Re-slotting suggestions as demand changes
– Integration with WMS or inventory platforms
– Reporting on space utilisation and travel time
Advanced tools, like our Orquestr8 Pick ABC Slotting Module, use live data and flexible rules to generate optimal layouts that evolve with your business.
Before you implement slotting, it’s important to evaluate several key factors to ensure long-term efficiency and success.
Consider whether your demand is stable or seasonal, as fluctuating demand may require more flexible slotting strategies. Take into account the variety in your SKUs’ size and shape, since this directly impacts how products can be stored and accessed. Analyse whether pickers are spending excessive time walking, as inefficient travel paths can reduce productivity and increase labour costs.
Ensure your warehouse management system (WMS) is capable of supporting dynamic slotting, which allows you to adapt quickly to changes in demand and inventory. Finally, think about how automation—such as robots or conveyors—may influence your layout decisions, as these systems often come with specific space and access requirements.