Case study · JTL-Wawi
Connecting two JTL-Wawi installations: one product range, kept in sync automatically
One brand, one retailer, two separate JTL-Wawi installations: the interface maintains products automatically, syncs stock every 15 minutes and creates a supplier order and a matching counter order for every sale, with no manual steps.
- System
- JTL-Wawi
- Industry
- Fashion & streetwear retail
The starting point
What wasn't working
Two companies, one shared product range: a retailer wanted to sell a partner brand's products in its own shop without holding its own stock. The goods stay owned and stock-managed by the brand, and both work out of the same warehouse. But each company runs its own separate JTL-Wawi.
Without an interface, that would mean creating every product twice, reconciling stock by hand and entering every order twice. That's error-prone and doesn't scale. The most critical requirement: stock levels in the two shops must never drift apart because of sales. If one shop sells an item, the other has to know within minutes.
The solution
How it works
The solution is a sync layer between the two ERP systems, built on one clear principle: the brand's JTL-Wawi remains the leading stock master, while the retailer's JTL-Wawi mirrors the product range and orders against it.
Data is read strictly read-only via SQL and written exclusively through JTL-Ameise, JTL's official import tool, so every change goes through JTL's own business logic and never directly into the database. Four building blocks work together: new products appear at the retailer overnight (including texts in two languages, prices, size variants and supplier data), images follow automatically, available stock is mirrored every 15 minutes, and every sale automatically creates the matching supplier order at the retailer plus a counter order with retailer prices at the brand, which reserves the stock and serves as the basis for invoicing between the two.
Reliability got particular attention. Every run is self-healing: before writing to the target systems it checks what already exists, it can be repeated any number of times and never creates duplicates. After every import the interface checks whether the transactions actually arrived instead of trusting success messages. Cancellations are monitored and flagged until the follow-up work is done. Credentials are stored encrypted, and every run is fully logged.
Product sync
New products from the brand appear in the retailer's JTL-Wawi overnight, with master data, EAN, size variants, texts in two languages and prices. Existing products are never overwritten.
daily · one direction
Image sync
Product images follow automatically half an hour later. No duplicates are created, only new images are added.
daily · one direction
Stock sync
The brand's available stock appears at the retailer as supplier stock and controls whether items can be sold in the shop. Every run mirrors the complete current state, so it heals itself after any disruption.
every 15 minutes
Procurement sync
Every sale automatically creates the supplier order at the retailer and the counter order with retailer prices at the brand: stock reservation and invoicing basis in one.
every 15 minutes · both directions
The result
What it changes day to day
- No more maintaining products twice. Products and their variants are kept up to date automatically
- Stock levels in the two shops are never more than 15 minutes apart, instead of being reconciled daily or not at all
- Zero manual steps per order, all the way to the finished supplier order and counter booking
- The counter order also provides the invoicing between the two companies, with the correct retailer prices
- Disruptions create no duplicates and no lost transactions, the next run catches up automatically
- No direct changes to the JTL database: writing happens only through JTL's official business logic
For your business
What you get
I can set this solution up in your business too: adapted to your processes and documented so your team can work with it right away.
Concept and quote after a free initial call. The scope depends on your system landscape and the building blocks you need.
- Analysis and concept: stock master, data flows and responsibilities clearly defined
- Setting up the complete sync layer on your server, including scheduled execution
- Built-in safety mechanisms: self-healing runs, post-import checks, cancellation monitoring, complete logs
- Clear documentation for your team and admins, including "what does each message mean?"
- Adaptation to your system landscape, e.g. different intervals, building blocks or shop platforms
FAQ
Quick answers
Does the interface write directly to the JTL database?
No. Reading uses a read-only SQL account, and writing happens exclusively through JTL-Ameise, so through JTL's official business logic with prices, taxes and platform sync. Data integrity in both ERP systems stays fully in JTL's hands.
What happens if something goes wrong, like a server restart mid-run?
Nothing bad: every run checks what already exists in the target systems before writing. It can be repeated any number of times without creating duplicates. After a partial failure, the next run automatically catches up on exactly what's missing.
Do I need a specific JTL license?
Only the fully automated order import requires the JTL Advance edition on one of the two installations. All other building blocks (products, images, stock) work regardless of license and can also be used on their own.
Does this work with other shop systems too?
Yes. The interface works at the JTL-Wawi level: which shops are connected to the two ERP systems (Shopify, WooCommerce, JTL-Shop or others) makes no difference to the sync.
Do both ERP systems have to run on the same server?
They did in this project, but it's not a requirement. Whether your system landscape fits and which building blocks you need is something we clarify in a short, free initial call.
Want this running in your business?
Describe your current process in two sentences. I'll get back to you with an honest assessment of what's possible.
Send a no-obligation request