What is slotting optimization?
Slotting optimization places inventory in locations that minimize picker travel time and maximize throughput. The goal: put your fastest-moving items in the most accessible spots. Poor slotting forces pickers to walk farther, reach higher, and bend more often—wasting time and causing fatigue. A well-slotted warehouse can improve pick rates by 20–40% without adding staff or equipment.
Velocity-based slotting
Analyze pick frequency over 30–90 days to identify A, B, and C velocity tiers. **A items** (top 20% of picks) belong in prime locations—waist height, near pack stations, along main aisles. **B items** (next 30%) fill secondary locations. **C items** (bottom 50%) go to back aisles, top/bottom shelves, and overflow areas. Re-slot seasonally when velocity patterns shift. Use your WMS pick history reports to identify candidates for relocation.
Cube and ergonomic factors
Velocity isn't everything. Consider item size (cube), weight, and pick frequency together. Heavy items belong at waist height regardless of velocity. Bulky items need shelf space that matches their footprint. Items picked together (kits, bundles) should slot near each other. The 'golden zone' (knees to shoulders) should hold items picked most frequently. Reserve floor locations for pallets and heavy cases.
Slotting analysis process
Step 1: Export pick data by SKU for the past 90 days. Step 2: Calculate picks per day and cube per unit for each SKU. Step 3: Classify into velocity tiers. Step 4: Map current slot locations and identify mismatches. Step 5: Create a relocation plan prioritizing high-impact moves. Step 6: Execute moves during low-volume periods. Step 7: Update WMS locations and verify accuracy. Start with the top 100 SKUs—they likely represent 50%+ of picks.
Ongoing maintenance
Slotting isn't a one-time project. Schedule quarterly reviews to catch velocity changes, new products, and discontinued items. Set alerts for SKUs that exceed slot capacity triggers. Train supervisors to spot slotting issues during floor walks. Use WMS reports to identify SKUs with excessive replenishment or travel time. Continuous improvement beats annual overhauls.
Guide
Warehouse Slotting Optimization
Design slotting strategies that keep picks short, replenishment predictable, and inventory accurate.
ABC/velocity
Classify SKUs by velocity and value. Place A-movers near packing and batch zones, while slower items occupy upper or back locations.
Replenishment rules
Set min/max thresholds so LollipopWMS triggers replenishment tasks before forward pick bins empty.
Pair these rules with receiving workflows to keep back stock organized.
Layout tips
- Keep heavy items at waist height to reduce strain.
- Group complementary SKUs for common orders.
- Label zones clearly so new associates navigate quickly.
Use batch picking insights to evaluate travel paths.
Calculator tie-in
Leverage slotting calculators in LollipopWMS to test scenarios before deploying layout changes. Review projected walking distances and labor savings in dashboards.
FAQs
How often should we re-slot?
Review slotting quarterly or after major promotions to stay aligned with demand.
Can we simulate changes first?
Yes. Use sandbox locations to test slotting rules before moving live inventory.
What data do we need?
Pull historical order volume, SKU dimensions, and handling requirements to make accurate plans.
Design faster pick paths
Slot smartly and let LollipopWMS handle replenishment prompts and performance tracking.