Facility Layout Design

Data first. Design second. Always.

The layout is not the product. The layout is the answer to a question: given what this operation needs to do, how should the space be organized to do it efficiently, safely, and with room to grow?

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Minimum Data Package

Never start designing without at least 80% of this data:

Order & Throughput:

• 12 months of order history (orders/day, lines/order, units/line, cases/order)
• Order profile by channel (B2B wholesale and DTC have completely different profiles)
• Inbound trailer volumes (receipts/day, pallets/receipt)
• Monthly on-hand inventory snapshots — at peak, not average

SKU Master:

• Number of active SKUs (by channel)
• Item dimensions (L × W × H) and weight per SKU
• Unit of measure, packaging type, special storage requirements

Velocity Data:

• Annual units sold per SKU (drives ABC classification)
• Cubic velocity (units sold × cube per unit) — drives slot sizing
• Seasonal peaks per SKU

Growth & Planning Horizon:

• 5-year growth plan by channel
• Seasonal spike magnitude and duration

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Order Profile Analysis: Most Important Dataset

Lines Per Order Distribution

Lines Per Order	Process Implication
Primarily 1-line	Each-pick automation, goods-to-person, or dedicated single-line zones
2-5 lines	Zone picking, batch picking, pick-and-pass systems
6-15 lines	Full warehouse tours, batch/cluster. Travel path optimization critical.
Mixed (all)	Multi-channel op — almost certainly needs zone separation

Real project example: CPG company running B2B wholesale (avg 22 lines/order) and DTC e-commerce (avg 1.8 lines/order) from the same building. Result: dedicated DTC pick module with carton flow and pick-to-light, completely separated from bulk pallet pick lanes. Two operations under one roof, each designed for its actual order profile.

ABC/Pareto Analysis

Category	% of SKUs	% of Total Picks	Placement
A items	~20%	~80%	Prime pick locations — golden zone, nearest shipping
B items	~30%	~15%	Secondary locations
C items	~50%	~5%	High-density storage, less-accessible

Velocity calculation methods:

• Basic: units sold / days (default ABC input)
• Weighted: (units sold × order frequency) / days (sporadic demand)
• Volume-based: (units sold × unit volume) / days (space-constrained ops — use for slot sizing)
• Value-based: (units sold × unit value) / days (loss/shrink risk)

Minimum analysis period: 3-6 months. Always analyze multiple windows for seasonality. A C-item in March may be an A-item in October.

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Seasonal Peak Design

Always design to peak, not average.

Vertical	Peak:Average Ratio	Peak Period
E-commerce (general)	2.0-3.5×	Nov-Dec (BFCM/holiday)
Toy / gift	3-5×	Oct-Dec
Apparel	1.5-2.5×	Spring/Fall + holiday
Consumer electronics	2-4×	Nov-Dec
Outdoor / garden	2-3×	Mar-May
Food & beverage (seasonal)	1.3-2×	Varies
B2B / Industrial distribution	1.2-1.5×	Lower peaks; steadier

Standard rule: Design to peak × projected Year 3-5 growth. Add 15-25% safety stock buffer during peak (supplier lead times stretch).

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Functional Area Sizing

Each zone in the facility is sized independently based on its specific throughput driver:

Receiving: Dock door count = f(trailer volume, throughput, dwell time, turn time). Use the Dock Door Calculator.

Storage: Storage positions = f(inventory at peak, SKU count, pallet size, rack type, cube utilization target). Always size to 85% utilization at peak.

Pick area: Forward pick sizing = f(SKU count in forward, days of supply target, cubic velocity per SKU, replenishment frequency).

Pack/VAS: Workstation count = f(orders/hr, pack time per order, ergonomic constraints).

Shipping staging: Staging lanes = f(trailer volume, staging dwell time, outbound door count).

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Planning Horizons by Investment Type

Physical infrastructure (building shell, dock doors, utilities, rack columns) → size to Year 5 peak. These are the hardest and most expensive to change. A dock door costs $40-80K to add post-construction.

Automation and mechanized systems (conveyors, sorters, AS/RS) → size to Year 3. Technology changes; don’t over-commit 5 years out.

Labor standards and process design → size to Year 3 peak. Labor is the most flexible resource.

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Design Tool Stack

• Excel — velocity pivot tables, order profile distributions, Pareto analyses, the Data Request Template
• SQL — extract from WMS/ERP. Key tables: ORDER_LINES, INVENTORY
• Power BI / Tableau — peak/valley visualization, ABC charts for stakeholder presentations
• AutoCAD / Visio — facility layout drawings; layering convention matters (rack, MHE, column grid, fire suppression all on separate layers)
• Alteryx — AI-enabled data cleaning for large/messy datasets

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WERC Best-in-Class Benchmarks for Layout Sizing

Metric	Best-in-Class	Median
Dock-to-stock time	<3 hours	—
Warehouse location utilization	92-95%	—
On-time shipping	>99%	—
Lines received/put away per hour	>68.9	—
Orders picked/shipped per person per hour	≥35	10

The gap between median (10 orders/hr) and best-in-class (35 orders/hr) is where good layout design lives. Zone structure, slotting, and properly sized pick locations drive a significant portion of that difference.