You sell in a shop, on your own website and on a marketplace, and the easy way to avoid clashes is to give each one its own slice of stock. It works until one slice sells out while another sits on the shelf. Here’s what a respected consulting firm and recent small-retailer data say about pooling stock instead, and how to do it without a big budget.

Should each sales channel have its own stock?

No. McKinsey says inventory should not be dedicated to one channel; pool it across channels instead. That guidance comes from its 2021 article on mastering the omnichannel supply chain, so it’s older than most of the data in this guide, but the principle hasn’t changed.

Think of it this way. If 20 units sit in “the website’s stock” and 20 in “the shop’s stock”, a rush of orders can empty one while the other still has plenty. A shared pool lets every channel draw from the same 40.

How should I set stock levels at each location?

Base them on forecast demand, past forecast accuracy, lead times and lead-time reliability at each location, according to McKinsey. In other words, a location that gets stock slowly or unreliably needs a bigger buffer than one that’s resupplied in a day.

McKinsey describes algorithms for this, but a small shop can start with a simpler version. For each product, write down how long a reorder takes and how often the supplier is late. Then set your reorder point accordingly.

How do I forecast when I sell through several channels?

Forecast by market and product group, then split the forecast by channel, allowing for cannibalisation where a strong online experience reduces in-store buying. The order matters because demand starts with the market and the product, not with the channel.

Cannibalisation just means one channel’s sales eating into another’s. If your website is doing well, your shop may sell less of the same item, and your forecast should expect it.

McKinsey advises that inventory should not be dedicated to one channel: pool it, then forecast by market and split by channel (McKinsey, 2021).

Related: How to stop overselling across your website, Shopee and Lazada

Who should own stock across channels?

McKinsey recommends assigning one person or team to own inventory across all channels. When the shop manager owns shop stock and the web person owns web stock, nobody owns the total.

In a small business that can simply be you, or one named staff member. The point is that someone is responsible for the combined number and for keeping it right.

Should customers see live stock?

Yes. Give shoppers real-time inventory visibility and reallocate orders continuously across channels and locations, according to McKinsey. Showing accurate availability stops the order that can’t be filled before it’s placed.

Real time doesn’t have to mean a screen of numbers on your site. It means the product page stops selling the item the moment the last one goes, wherever it went.

Does a physical store help online sales?

Pre-pandemic research cited by McKinsey found that opening a new store raised a retailer’s website traffic by 37% in the following quarter (ICSC study, 2018). So stores and websites can feed each other rather than compete.

That study is from 2018, so read it as evidence for the relationship, not a number to plan around. It supports keeping both channels on one stock pool, because customers move between them.

Why does shared stock matter financially?

Out-of-stocks cause 65.6% of the roughly US$1.7 trillion lost to inventory distortion each year, or 6.2% of retail sales, according to IHL Group figures reported by Retail Insight Network (2026). Separate stock slices make out-of-stocks more likely, because one channel can run dry while another holds spare units.

Those are global figures, not a Singapore number. They still show where the money goes: running out costs more than having a little too much.

How many small retailers have disconnected systems?

About a third of small retailers report disconnected or glitchy systems, and nearly half want real-time inventory data, according to the Global Payments 2025 Retail Inventory Report of 200 small retailers. The report is small, so treat it as a pointer.

It matches what many owners feel: the tools exist, but they don’t talk to each other. A shared pool needs the shop, website and marketplaces to read and update one count.

Opening a new store raised a retailer’s website traffic by 37% in the following quarter in pre-pandemic research cited by McKinsey (ICSC, 2018).

How many learn of a stock-out only at the sale?

Nearly one in four small retailers only find out when a customer tries to buy the item, according to Global Payments (2025). For those shops, the first alarm is a customer.

Nearly 1 in 4 small retailers only learn an item is out of stock when a customer tries to buy it (Global Payments, 2025).

Will stores remain a sales channel?

Yes. Forrester forecasts US e-commerce at US$1.8 trillion, or 29% of retail sales, by 2030, leaving in-store sales at 71%, so most shops will keep selling in more than one place. That’s a US forecast, not a Singapore one.

If you’ll keep a shop, a website and probably a marketplace store, a shared pool is the setup that scales with you. Our guide to why a Singapore shop’s POS should share stock with its online store covers the till side. Asalta Inventory keeps one stock count across stores, websites and marketplaces, which is the pooled setup described above. It’s one option to compare, and the principles here apply to whichever tool you choose. You can read more on the Asalta Inventory page.

Key Takeaways

• Pool the stock: inventory should not be dedicated to one channel.
• Name an owner: one person or team should own stock across all channels.
• Show live availability: stop selling an item the moment it’s gone.
• Know the cost: out-of-stocks cause 65.6% of inventory distortion.
• Expect to keep stores: Forrester forecasts in-store sales at 71% of US retail in 2030.