How to Calculate WMS ROI
— A Framework Your CFO Will Trust
Before committing to a Warehouse Management System, every finance team asks the same question: "When does it pay back?" This article walks through the five-system model MOLOG uses to turn real warehouse data into a defensible payback period.
WMS ROI is calculated by comparing the AS-IS cost (before WMS) against the TO-BE cost (after WMS) across five warehouse processes — Inventory Lost, Receiving, Shipment Productivity, Picking Accuracy, and Stock Turnover. Total annual savings from all five processes, divided into the project cost, gives the payback period. Mid-size warehouses typically reach payback within 12–24 months.
What Does WMS ROI Actually Mean?
In the context of a WMS investment, ROI is the ratio of annual cost savings the system generates versus the total cost of the project. Warehouses still running on spreadsheets, paper pick lists, or basic ERP inventory modules tend to carry hidden costs in several places: shrinkage from inaccurate stock counts, labor hours wasted searching for misplaced goods, and return-processing costs caused by picking errors.
The MOLOG approach is to quantify each of those cost pools in AS-IS terms first, then model the TO-BE state using improvement rates validated by real deployments. The central assumption used across all calculations is a working calendar of 26 days per month, 8 hours per day — a standard baseline for Thai industrial operations.
Once every cost pool is modeled, the math is straightforward: add up the monthly savings across all five processes, multiply by twelve, and divide the project cost by that number. The result is how many years until the investment pays for itself.
The Five Processes Used to Measure ROI
These five processes are chosen because each can be converted into a concrete Thai-baht figure using data the warehouse already has — headcount, wages, order volumes, and stock values. There is no need for soft-benefit estimates.
| # | Process | What It Measures | Improvement After WMS |
|---|---|---|---|
| 1 | Inventory Lost | Cost of stock shrinkage / discrepancies | Stock accuracy rises from ~97% to 99%+ — shrinkage cost falls proportionally |
| 2 | Receiving Time per PO | Labor cost of inbound goods receipt | 30% faster |
| 3 | Shipment Productivity | Labor cost: pick / pack / check per SO | Picking 50% faster · Packing & Checking 30% faster |
| 4 | Picking Accuracy | Cost of returns caused by wrong-item picks | Picking errors reduced by 90% |
| 5 | Stock Turnover | Holding cost and opportunity cost of slow inventory | Turnover improved by 20% |
These improvement rates are drawn from MOLOG client data, not industry averages. They represent the conservative end of what a well-implemented WMS delivers, making them suitable for a business case rather than a sales pitch.
The Calculation Formula, Step by Step
The core labor-cost formula converts time and headcount into a monthly baht figure for each process:
Labor Cost Formula (Per Process)
AS-IS Cost / Month = (Minutes per task × Tasks per month) ÷ (26 days × 8 hrs × 60 min) × Monthly wage
TO-BE Cost / Month = AS-IS Cost × (1 − Improvement%)
Monthly Saving = AS-IS Cost − TO-BE Cost
Total ROI Formula
Annual Saving = Sum of monthly savings across all 5 processes × 12
Payback Period (years) = Total Project Cost ÷ Annual Saving
Every variable in this model is an operational figure the warehouse team already tracks — no consultancy jargon required. This makes the output easy to audit and straightforward to present to a finance committee.
A Worked Example
The following calculations use the sample assumption set from MOLOG's ROI model. Actual figures will differ based on your operation's size and characteristics.
Base assumptions: 26 working days/month, 8 hours/day, warehouse staff wage 23,000 THB/month.
Process 2: Receiving Time per PO
Assume 120 POs per month, each taking 50 minutes to receive.
- Total available minutes/month = 26 × 8 × 60 = 12,480 minutes
- AS-IS cost = (120 × 50) ÷ 12,480 × 23,000 = 11,058 THB/month
- TO-BE cost (30% faster) = 11,058 × 0.70 = 7,741 THB/month
- Monthly saving: 3,317 THB (~39,800 THB/year)
Process 3: Shipment Productivity
Assume 1,000 SOs per month. Picking: 20 min/SO, Packing: 5 min/SO, Checking: 5 min/SO. Staff wage: 23,000 THB. Reach truck driver: 35,000 THB + rental 35,000 THB/month.
- Picking AS-IS = (1,000 × 20) ÷ 12,480 × 23,000 = 36,859 THB/month
- Picking TO-BE (50% faster) = 18,430 THB/month → saving 18,430 THB/month
- Packing AS-IS = (1,000 × 5) ÷ 12,480 × 23,000 = 9,215 THB/month
- Packing TO-BE (30% faster) = 6,450 THB/month → saving 2,765 THB/month
Process 4: Picking Accuracy
Assume 50 returns per month from 1,000 orders, 50 min/return, packaging cost 20 THB, replacement shipping 50 THB per return.
- Return labor cost = (50 × 50) ÷ 12,480 × 23,000 = 4,607 THB/month
- Packaging + replacement shipping = 50 × (20 + 50) = 3,500 THB/month
- AS-IS total return cost = 8,107 THB/month
- TO-BE (90% error reduction) = 811 THB/month → saving 7,297 THB/month (~87,560 THB/year)
When all five processes are totaled, a warehouse of this scale saves several hundred thousand baht per year — typically placing the payback period well within the 12–24 month range for a mid-size operation.
Key Takeaways Before You Run the Numbers
- Collect complete AS-IS data first: POs per month, SOs per month, minutes per task, staff wages, current stock value, and current error or return rates. The model is only as accurate as the inputs.
- Use validated improvement rates: Receiving +30%, Picking +50%, Packing & Checking +30%, Picking Errors −90%, Stock Turnover +20% — these come from real client deployments, not theoretical benchmarks.
- Account for the full project cost: subscription fees, hardware (scanners, printers), implementation, and training. MOLOG WMS is billed monthly as SaaS, which significantly lowers the upfront capital requirement.
- Compare against your industry benchmark: Warehouse costs for FMCG businesses typically run around 8% of revenue. If yours is higher, a WMS will pay back faster than the model suggests.
- Get a professional ROI report: MOLOG prepares a customized ROI Summary Report from your actual data within 7 business days. Email sale.th@mologtech.com to request one.
Frequently Asked Questions about WMS ROI
What goes into a WMS ROI calculation?
A WMS ROI calculation covers five core warehouse processes: Inventory Lost (shrinkage costs), Receiving Time per PO, Shipment Productivity (pick/pack/check labor), Picking Accuracy (returns from mis-picks), and Stock Turnover (holding and opportunity cost). Each process is measured as a monthly cost before WMS (AS-IS) and after WMS (TO-BE). The combined annual savings divided by the total project cost gives the payback period.
How long does it typically take to see ROI on a WMS?
For mid-size warehouses processing 1,000+ shipment orders per month, most businesses achieve payback within 12–24 months. The timeline depends heavily on current error rates, labor costs, and the scale of operations. MOLOG prepares a customized ROI Summary Report using your actual data within 7 business days so you can see a precise number before committing.
Is WMS cost-effective for a small warehouse?
The rule of thumb is: if you manage more than 500 SKUs or ship more than 50 orders per day, a WMS typically pays for itself within a reasonable timeframe. Below those thresholds, the ROI may be harder to justify in the short term. That said, starting early builds a foundation of accurate stock data before problems scale — and MOLOG's SaaS model keeps the upfront investment low compared to on-premise systems.
What costs should be included in the "project value" side of the ROI equation?
The total project cost should include: monthly subscription fees (multiplied over the contract term), hardware such as handheld scanners and label printers, implementation and configuration fees, and staff training. Because MOLOG WMS is a SaaS solution billed monthly, the large upfront capital outlay typical of on-premise systems is eliminated — making the ROI timeline shorter from day one.
Where do the improvement percentages in the MOLOG ROI model come from?
The rates — Receiving 30% faster, Picking 50% faster, Packing and Checking 30% faster, Picking Errors reduced by 90%, and Stock Turnover improved by 20% — are derived from actual client deployments, not marketing estimates. Each figure can be traced back to before-and-after operational data from warehouses of similar scale and complexity.
Get Your Custom WMS ROI Report — Free, Within 7 Days
Our team will take your actual warehouse data and produce a detailed ROI Summary Report so you can see precise payback figures before you commit. Contact us at sale.th@mologtech.com or book a demo to get started.
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