Data strategy
What is a single source of truth, and how do you build one in six weeks?
By the Trigno team · · 7 min read
“Single source of truth” is one of the most overused phrases in data. In practice it means something simple: when two people ask the same question, they get the same answer, and everyone trusts where it came from. Here is how to get there without a multi-year programme.
Why your systems disagree
Your CRM, finance system, SharePoint lists and spreadsheets were set up at different times, by different people, for different jobs. Each records the same customers and projects slightly differently, under different IDs, updated at different times. Disagreement is normal. The problem is that nobody can see it, so every meeting starts with “whose number is right?”
The four rules that make it work
- One ID per thing. Every customer, project or product gets one identifier, linked to its ID in each source system.
- One owner per field. Each piece of data has exactly one system or person responsible for it, so updates never overwrite each other.
- Conflicts are shown, never hidden. When sources disagree, the difference is flagged to a named person to fix at source.
- Everything is audited. Every change records who made it, when and what it was before.
A six-week plan
- Week 0: a Health Check to agree which questions matter most and which systems hold the answers.
- Weeks 1–2: connect the sources with read-only access and produce a data-quality report: duplicates, gaps and conflicts.
- Weeks 3–5: build the trusted database, the matching rules, the conflict queue, a simple app for corrections, and the first dashboards.
- Week 6: train the team, hand over and retire the spreadsheets that are no longer needed.
A real example
For a national aerospace R&D funding body, project information was spread across Dynamics 365, SharePoint lists, funder data and a legacy spreadsheet, each with its own IDs. We linked 654 projects to one ID, gave each field a single owner, flagged conflicts to a data steward instead of overwriting them, and added analysis dashboards and an AI assistant on top. The result was one trusted view of a £2.9bn portfolio.
Tip: Start with the three questions your leadership asks most often. If the single source of truth answers those reliably, everything else can follow.
Common questions
Do we have to replace our existing systems?
No. A single source of truth sits alongside your systems and reads from them. Your teams keep working in Dynamics, SharePoint and the rest.
What happens when the data is wrong?
Conflicts and gaps are flagged to the person responsible, who fixes them in the original system. The single source of truth then updates automatically.
Is this only for large companies?
No. Smaller businesses often benefit most, because a handful of people spend hours every week reconciling spreadsheets by hand.