A single source of truth is the agreement that every piece of data has one leading source: customer data lives in the CRM, inventory in the till system or WMS, invoices in the accounting system. All other systems follow that source via integrations, instead of keeping their own copies.
A single source of truth in practice
Without that agreement, the familiar picture emerges: three versions of the same customer, stock levels that differ per system, and meetings about whose figure is correct. The problem is rarely bad intent — it's the absence of an agreed owner per piece of data, so everyone keeps a local record of what they need.
The order is always: first name the leading source per data type, then integrate. An integration that synchronises two 'owners' only automates the conflict. How to tackle this step by step is explained in Preventing duplicate work.
Related terms
- Data model — A data model is the structure in which data and its mutual relationships are recorded: which tables exist (customers, orders, products), which fields they contain and how they are linked to each other.
- API integration — An API integration is a connection between two software systems that automatically exchange data via their APIs — for example orders from a webshop to the accounting system, or placements from an ATS to invoicing.
- CRM — A CRM (Customer Relationship Management system) is the system in which an organisation records customers, contacts, leads and the associated interactions — from first contact to quote and aftercare.
- ERP — An ERP (Enterprise Resource Planning system) is a single system that brings together a company's core administration: finance, purchasing, inventory, orders and often projects or production too.