Data consistency means the same piece of information has the same value in every system in your company. The most reliable way to get there is the single source of truth principle: each type of data is created and changed in only one system, and all other systems only read it. The full set of core records such as products, customers and suppliers is called master data.
As companies grow, the number of systems grows too: ERP, e-commerce site, marketplaces, dealer portal, CRM, warehouse software, Excel spreadsheets. Every new system brings its own product list and its own customer records. Nobody enters wrong data on purpose, but if the same information is kept in four places, sooner or later it splits into four different values.
The bill for inconsistency
Inconsistent data creates hidden costs:
- A customer sees one price on the website and a different one on the invoice.
- A product shown as in stock on the dealer portal isn't in the warehouse.
- The same customer is recorded twice in the CRM and under three different company names in the ERP.
- The monthly report shows different revenue depending on which system it was pulled from.
- The team spends part of every day answering the question "which one is right?"
None of these problems looks big on its own. Added together, they wear down both customer trust and the quality of decisions.
An ownership map for a single source of truth
The first step toward a solution is an ownership map. For each type of data, ask three questions: where is it created, who can change it, and who only reads it?
| Data | Owner (single source of truth) | Readers |
|---|---|---|
| Product code, unit, tax rate | ERP | Website, marketplaces, dealer portal |
| Product description, images, SEO copy | E-commerce or content system | Marketplaces, dealer portal |
| Stock quantity | ERP or warehouse software | All sales channels |
| Base price | ERP | Channels derive their own prices by rule |
| Customer/supplier account and balance | ERP | Dealer portal, CRM |
| Leads and contact history | CRM | Sales team |
| Order | The channel it came from, then the ERP | Warehouse, accounting |
This table is different at every company; what matters is that every row has a single owner. A row with two owners is a sign of a future inconsistency.
Deciding on ownership
These criteria help when deciding which system should be the owner:
- Who knows the data best? The marketing team knows the technical description of a product; accounting knows the tax rate. The owning system should be the one where the team that knows the data works.
- Where is the legal record? Data with legal consequences, such as invoices, customer accounts and stock, should usually stay in the ERP.
- Which system lasts longest? Websites get rebuilt and marketplaces change; the ERP is usually the most permanent.
- Is change history kept? A system where you can see who changed what and when is better suited to ownership.
Locking editing in the other systems
After the ownership decision comes the hardest step: turning off editing of that field in the other systems. If the price field on the website comes from the ERP, that field should be read-only in the site's admin panel. Otherwise, in a rush someone will change the price by hand on the website, and at the next sync the change will be wiped out or, worse, spread in the wrong direction.
If locking isn't possible, at least add a warning on screen saying "this field comes from the ERP, don't change it here" and report differences regularly.
Cleanup and upkeep
Setting new rules isn't enough; the existing mess needs cleaning up too. Merging duplicate customer records, deactivating unused product codes and standardizing unit and category names are all part of the job. Turning cleanup into a small, regular habit rather than treating it as a one-off project gives more lasting results.
Practical checklist
- All systems and the data types they hold are listed
- Each data type has a single owner, in writing
- The related fields are read-only in systems that don't own them
- Matching keys (product code, tax number) are formatted the same way in every system
- Duplicate records have been cleaned up
- Differences between systems are reported regularly
- The ownership map is updated whenever a new system is added
How we do it at Globya
Before starting an integration project, we draw up the ownership map together with you; this document becomes the shared reference everyone looks at for the rest of the project. We build the connections according to this map as part of our integration service and turn off editing in systems that don't own the data. Consistent data is also a precondition for sound reporting; READERP, which reads ERP data and turns it into management-ready reports, works read-only on the common ERP and finance platforms, led by Netsis and Logo, the ERP systems widely used in Türkiye, and never writes a single line to the ERP. Companies working with a dealer network can also take a look at our wholesale and B2B distribution page.
Frequently asked questions
Do our Excel spreadsheets count as a system too?
Yes, and that is usually where most inconsistencies come from. If data kept in Excel also exists in another system, it must be clear which one owns it; where possible, Excel should be used for reading only.
Our ERP isn't suited to holding product descriptions. Is that a problem?
No. Ownership can be split by data type. Product code and price can stay in the ERP while descriptions and images stay in the e-commerce system; matching is done on the product code.
How long does this work take?
It depends on the number of systems and the state of the existing data. The ownership map usually comes together quickly; the cleanup part takes longer depending on how messy the data is. Pricing follows in a written proposal after the discovery call. Describe your needs now in 3 minutes
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