What Is VMI, and How Does It Work?
In Vendor Managed Inventory (VMI), the supplier takes responsibility for monitoring inventory at the customer’s location and initiating replenishment when needed. The customer shares stock levels and sales data; the supplier uses them to work out what to send and when, and ships it before the customer runs out.
With a more traditional purchase order, the buyer is the one deciding when to reorder. They monitor inventory, decide when stock is getting low, and then send you an order. While this can work when demand and lead times are steady, modern supply chains don’t always work that way. Between orders there’s no visibility on what’s selling and what’s still on the shelf.
Vendor Managed Inventory gives you visibility and more control over replenishment. The customer shares their inventory and sales data, usually on an automated feed. You compare that to stocking rules you both signed off on, figure out what needs to be replenished, and create the order yourself. Depending on the setup, the customer either takes the order automatically or approves it.
The replenishment decision moves to the supplier, who tends to have a better handle on the lead times, production limits, and demand changes throughout the year.
When both sides are sharing info you get better visibility into the customer’s inventory and sales and they get a better view of how well you’re fulfilling.
VMI stands for Vendor Managed Inventory. Sometimes you’ll see it referred to as supplier managed inventory, vendor inventory management, and vendor management inventory. If one of those turns up in a contract or a retailer scorecard, the VMI meaning is the same.
How a Vendor Managed Inventory Program Works
First, both sides agree on the rules, including minimum and maximum stock levels for items and locations, fill dates, order frequency, minimum order quantities, lead times, and how to handle promotions and seasonality.
These targets are then the benchmark for replenishment decisions. VMI programs that struggle initially often realize the initial assumptions were erroneous or that targets were never fully agreed on.
1. The customer shared inventory and sales data
The customer sends you inventory levels and sales activity on an agreed schedule, usually daily or weekly. In an EDI setup, that data often comes through a product activity report or inventory advice.
At a minimum, you need to know what is on hand, what has sold or shipped, what is already on order, and what is still in transit or sitting elsewhere in the customer’s network. That information should be broken down by item and location.
2. You forecast demand and apply the stocking rules
Review order history and sales data to see what the buyer has decided to purchase and what customers actually bought. These usually give you a much clearer picture of demand. After that, you want to compare expected demand with current inventory and the minimums and maximums already agreed on.
3. You create the replenishment order
You may need to account for pallet quantities, freight costs, minimum order sizes, and what you can actually supply at the time. Depending on the agreement, you might create the order and the customers receives the confirmation. In other agreements, the customer reviews and approves the order before it’s released.
4. Stock ships and the customer confirms receipt
Once the order is ready you’ll ship the good and the customer will confirm receipt. The ownership transfers depending on your agreement. In many VMI programs ownership changes when the good are received by the customer. Sometimes with consignment or scan-based trading you may continue to own the inventory until it is used or sold.
5. You review performance and adjust
Both sides should review performance regularly. Generally you’ll check fill rate, days of supply, in-stock percentages, forecast accuracy, and how many expedited orders there have been.
Where VMI Sits in the Supply Chain
VMI can be confused with other inventory models as they are often used together. The differences are important when you define responsibilities and writing contracts.
Consignment inventory is about ownership. The supplier continues to own the stock until a customer sells it or uses it. VMI is about replenishment responsibility, mainly who decides when and how much to reorder. A program can use both models together but can exist on their own. Before agreeing to terms it’s worth learning the difference between VMI and consignment inventory.
Just-in-time inventory is focused on keeping stock levels as low as possible without breaking operations. VMI helps decide when replenishment should happen and how much stock to send. Because they solve different parts of inventory, these processes can work well together. Our guide to just-in-time inventory management explains the model in more detail.
Collaborative planning, forecasting and replenishment takes the collaboration a step further. Instead of the supplier managing replenishment based on shared data, both sides work together to develop the forecast. VMI can be a helpful step toward that kind of shared planning.
Scan-based trading combines VMI with supplier ownership of the inventory until the product is sold at the register.
The Benefits of Vendor Managed Inventory
For the supplier, VMI is primarily a tool for growth and operational efficiency. When you have direct visibility into how your products are moving at the customer level, you are no longer flying blind between order cycles. You can act on the data rather than react to it.
The outcomes suppliers most commonly see from VMI include:
- Increased sales. Better visibility into sell-through data means replenishment happens before stockouts occur, and products stay on shelves. Sales that would have been lost to an empty peg or bare shelf are captured instead.
- Stronger customer relationships. Taking on inventory management responsibility positions the supplier as a strategic partner, not just a vendor. When a supplier demonstrates consistent product availability and a proactive approach to replenishment, that relationship deepens.
- Reduced order management overhead. Managing inbound orders from dozens or hundreds of retail or distributor locations involves significant manual work. VMI consolidates that into a data-driven process, reducing the burden on order management and customer service teams.
- Smarter demand intelligence. Access to downstream inventory and point-of-sale data gives suppliers a clearer picture of actual demand patterns, seasonal shifts, and regional differences. Over time, that data becomes a planning asset.
What Retailers and Distributors Gain
VMI is sometimes misread as a program that benefits the supplier at the retailer’s expense. The opposite is true. The retailer or distributor gives up some ordering control in exchange for significantly better outcomes.
- Fewer stockouts. This is the most immediate benefit. When the supplier is actively monitoring inventory and responding to movement, products stay in stock more consistently. For retailers, that means fewer lost sales and fewer frustrated customers.
- Reduced ordering workload. Creating and managing purchase orders for hundreds of SKUs across a supplier portfolio is labor-intensive. VMI removes that burden from the retailer’s team. Instead of spending time on routine ordering, staff can focus on more strategic tasks.
- Lower carrying costs. Because replenishment is tied to actual consumption rather than periodic ordering cycles, inventory levels tend to be more precisely calibrated. Retailers carry less excess stock without running the risk of running out.
- Better supplier collaboration. Retailers in VMI programs typically have greater visibility into their supply chain performance, shared dashboards, service metrics, and replenishment history. That transparency creates a basis for a more productive, longer-term relationship.
The VMI model works because its incentives are aligned. Both parties want the same thing: the right product, in the right quantity, at the right time.
Vendor Managed Inventory Examples
VMI can work differently depending on the type of customer and the relationship you have with them. The examples below show how VMI works in different settings: what data is shared, who makes the replenishment decision, and who owns the inventory until it’s sold.
A CPG Supplier Replenishing a Grocery Distribution Center
A food manufacturer supplies several hundred SKUs to a grocery chain’s regional distribution centers. Each week, the retailer shares inventory levels, recent store shipments, and open purchase orders by item and location.
The supplier uses that data to forecast demand, compares it with the agreed minimum and maximum days of supply, and creates replenishment orders in full pallets or truckloads. Ownership of the inventory transfers to the retailer when the shipment is received at the distribution center.
Promotions are handled separately. Expected demand increases are agreed in advance and added to the replenishment rules for the promotional period, helping avoid stockouts caused by relying on normal demand patterns.
This is a common VMI setup in consumer goods. You can learn more in our guide to how VMI works for CPG suppliers.
A Store-Level Program Using Scan-Based Trading
A beverage supplier delivers directly to several hundred retail stores. Each day, the retailer shares point-of-sale data by store and item, giving the supplier a clear view of what is actually selling.
The supplier keeps ownership of the inventory until each item is scanned at the register. That sale triggers payment and feeds into the next replenishment decision, so there is no need for a traditional purchase order and receipt process.
Because the supplier owns the inventory until it sells, it also takes on the risk for shrink and damaged stock. In return, it gets direct access to store-level sales data, which gives it a much stronger basis for forecasting demand and planning replenishment.
An Industrial Supplier Managing Bin Stock on Site
An MRO distributor keeps commonly used items such as fasteners, fittings, and other consumables in bins at a manufacturer’s facility. Because the stock is used on site, replenishment is based on actual consumption, usually captured through scans or regular inventory counts.
The distributor monitors each bin against agreed minimum and maximum levels and restocks as needed during scheduled service visits. The inventory remains on consignment until it is issued to a work order, so the manufacturer only pays for what it uses.
For the plant team, the main benefit is simplicity. Employees do not need to raise a requisition every time they need another box of bolts or fittings.
Vendor Managed Inventory Company Examples
One of the best-known examples of VMI is the relationship between Walmart and Procter & Gamble, which began in the late 1980s. It is often cited as an early example of modern VMI in retail and is still used to explain how the model works in practice.
Since then, VMI has become common across a much wider range of industries, including consumer goods, industrial distribution, healthcare, and building products.
Vendor Managed Inventory Advantages and Disadvantages
As you’ve read above, the benefits of VMI are clear. But it also comes with some challenges. Most of them can be managed as long as you sort them out before the program starts.
Your forecast depends on the quality of the customer’s data. If inventory counts are off, data is late arriving, or stock in a back room is missing from the feed, your decisions on replenishment will be based on a partial picture. Define what acceptable data looks like upfront, including how often it will be shared and how errors or missing info will be handled.
Forecasting responsibility shifts to you. In a traditional purchasing model, the buyer is responsible for deciding how much to order. With VMI, much of that responsibility moves to the supplier. Forecast accuracy therefore becomes something both sides need to review together, especially when demand differs significantly from expectations.
Working capital requirements can increase. If the program includes consignment or scan-based trading, you may own the inventory for longer and receive payment later. The potential cash-flow impact should be understood before agreeing to the commercial terms.
VMI requires trust and clear agreements. The supplier is making inventory decisions on the customer’s behalf and using sales and inventory data the customer has chosen to share. Both sides need clear service levels, ownership terms, responsibilities, and a process for dealing with major forecast or inventory issues.
Manual processes become harder to manage as the program grows. A small VMI program with a few customers and SKUs may be manageable in spreadsheets. Once you are replenishing hundreds of items across multiple locations, manual review becomes much more time-consuming and increases the risk of errors. At that point, automation becomes much more important.
What You Need to Run VMI
A VMI program depends mainly on two things: getting reliable data from the customer and having the right process for turning that data into replenishment decisions.
Reliable inbound data from the customer.
You need current inventory and sales data for each location, shared often enough to reflect how quickly the product moves. With EDI, that may come through a product activity report such as an 852, an inventory inquiry or advice such as an 846, or a product transfer and resale report such as an 867. The connection also needs to be monitored. If a feed stops for several days without anyone noticing, replenishment decisions quickly start relying on outdated information.
Forecasting and replenishment automation.
Receiving the data is only the first step. You still need to turn it into a demand forecast, compare that forecast with your stocking rules, and calculate what should be replenished. Inventory forecasting and replenishment automates that process, making it possible for planners to manage far more accounts without reviewing every item manually.
A way to manage exceptions.
Once a VMI program is running smoothly, most replenishment decisions should be routine. Planners can then focus on the situations that need attention, such as new products, promotions, sudden changes in demand, or supply shortages. Automated inventory planning helps separate those exceptions from everyday replenishment.
Clear allocation rules when supply is limited.
There will be times when you cannot fill every order in full. Decide in advance how limited inventory will be allocated across customers or locations so the same rules are applied consistently.
If you are looking at what it takes to run a VMI program from end to end, our VMI software overview covers the main components.
Is Vendor Managed Inventory Right for Your Business
A few practical factors can tell you whether VMI is a good fit.
Customer concentration matters. VMI takes time to set up for each trading partner, so it tends to deliver the most value when a relatively small number of customers account for a large share of your volume.
Consider how your products sell. Fast-moving items with fairly predictable demand are usually easier to manage with agreed replenishment rules. Slower or highly seasonal products may need more advanced forecasting before VMI works well.
Make sure the customer can share reliable data. You need consistent location-level inventory and sales information to make good replenishment decisions. It is worth confirming that early, since poor or inconsistent data can stop a VMI program before it gets very far.
Make sure someone owns the program internally. VMI still needs active management. Someone has to maintain the replenishment parameters, handle exceptions, monitor performance, and lead regular reviews with the customer. That responsibility should be clearly assigned from the start.
Everything described in this blog: core VMI program management, AI-driven demand forecasting, constrained supply allocation, planning automation, and distributor order collaboration, is available within TrueCommerce Datalliance VMI.
Datalliance VMI has been a pioneer in cloud-based vendor managed inventory since 1991 and is trusted by brands including Unilever, General Mills, Kimberly-Clark, Ocean Spray, and many others, managing more than 25 million SKUs and $50 billion in inventory across 20,000+ locations worldwide.
If you’re evaluating VMI for the first time or looking to modernize an existing program, we’d welcome the conversation.
Learn more about TrueCommerce Datalliance VMI or speak with a VMI specialist to see how the platform works in practice.