Independent data advisory · Est. 2014
Mastery is making data behave.
We are a small, senior advisory practice for data governance, master data, and data quality. No frameworks-on-slides theatre — we sit with your data until it holds.
Move your cursor — that turbulence is ungoverned data. Our work is making it flow.
Most data programmes fail quietly — in the eighteen months after the kickoff deck.
Governance that holds
Policies, ownership, and decision rights that survive the quarter after the consultants leave — written for the people who actually run the data.
One version of the truth
Master and reference data consolidated into a source you can name, with matching, survivorship, and stewardship that hold up under audit.
Quality you can prove
Data quality measured, not asserted: rules, thresholds, and a scorecard your board reads in a minute and trusts.
Why independent
We do not resell a platform, and we take no kickbacks from vendors. The recommendation you get is the one we would make if it were our own data on the line.
Years advising data leaders, independently.
Median drop in data incidents within 18 months.
Enterprises advised across finance, health, and logistics.
Vendors we resell. The advice is unconflicted.
Three moves. Diagnose, design, embed. Then we get out of the way.
Diagnose
Two weeks inside your data. We trace lineage, interview stewards, and map where decisions actually break. You get an honest maturity read — not a sales pitch.
Design
A governance and master-data operating model sized to your organisation: ownership, policies, the catalogue, the quality rules. Drawn to be run, not framed.
Embed
We sit beside your teams while it takes hold — stewardship rituals, scorecards, the first hard data decisions made the new way. We leave when it runs without us.
Where we are brought in.
Data governance framework
Operating model, policies, ownership, decision rights, council design.
SCOPE THISMaster & reference data
MDM strategy, matching & survivorship, stewardship, tool-agnostic selection.
SCOPE THISData quality
Rules, profiling, thresholds, remediation, the board-readable scorecard.
SCOPE THISData strategy & operating model
Target state, roadmap, funding case, the org shape to deliver it.
SCOPE THISRegulatory & compliance
GDPR, DORA, BCBS 239 — governance evidence that survives the examiner.
SCOPE THISCatalogue & lineage
Metadata, business glossary, end-to-end lineage people will actually maintain.
SCOPE THISCertified Data Management Professional — Master level (DAMA International).
Engagements aligned to DAMA-DMBOK and the EDM Council DCAM framework.
Every engagement led by a practitioner with 15+ years in the field. No bench, no junior hand-off.
Field note“A data catalogue nobody updates is just a more expensive spreadsheet.”
On metadata that lives — Marcus Adeyemi
Field note“Most "data quality problems" are ownership problems wearing a technical costume.”
On stewardship — Marcus Adeyemi
Field note“You cannot govern what the business cannot name. Glossary before tooling.”
On where to start — Marcus Adeyemi
One senior practitioner on every engagement — named, not a bench.
Marcus Adeyemi
PRINCIPAL & FOUNDER · AUTHOR
- — CDMP Master (DAMA International)
- — 18 years in data management
- — Ex-Head of Data Governance, tier-1 bank
- — DCAM-assessed practitioner
Mastering Data Management is led by Marcus Adeyemi, who has run governance and master-data programmes inside regulated enterprises for 18 years — including a tier-1 bank's BCBS 239 remediation. Every engagement is delivered by a practitioner at this level. There is no junior bench and no hand-off.
The practice publishes its method openly and keeps a public privacy notice and terms of use. Engagements run under a signed letter; advice is vendor-neutral, with no platform resale.
Plain answers to the questions we are asked most.
What is data governance?
Data governance is the operating model that decides who owns data, how it is defined, and how decisions about it are made. It sets policies, ownership, and decision rights so an organisation can trust its data. In practice it is run by named stewards and a governance council, not a one-off document.
Aligned to DAMA-DMBOK 2
What is master data management (MDM)?
Master data management consolidates an organisation’s core entities — customers, products, suppliers — into one governed, authoritative record. It combines matching, survivorship rules, and stewardship so every system reads the same truth. Done well, MDM removes duplicate records and reconciliation effort and makes downstream analytics trustworthy.
Aligned to DAMA-DMBOK 2 & ISO 8000
How does a data quality scorecard work?
A data quality scorecard measures defined dimensions — completeness, validity, uniqueness, timeliness — against agreed thresholds, then reports a score per dataset and owner. Rules run on a schedule, failures route to a steward, and the trend is shown to the board in a minute. It turns "the data feels off" into a number a decision can be made on.
Dimensions per DAMA-DMBOK data quality
When should an enterprise hire an independent data governance advisor?
Hire an independent advisor when data incidents recur, a regulator asks for governance evidence (BCBS 239, DORA, GDPR), or an MDM/catalogue programme has stalled. Independence matters: an advisor who resells no platform recommends what fits your data, not a licence. Most engagements start with a two-week diagnostic.
Regulatory references: BCBS 239, DORA, GDPR
Sources & standards referenced
Further reading: Data governance, Master data management, Data quality (Wikipedia).
Reviewed by Marcus Adeyemi, CDMP Master — last reviewed June 2026. Figures are drawn from Mastering Data Management's own engagement records, 2014–2026. Spotted an error? Tell us — we correct and date every change. See our editorial & content policy.
Governance isn't a document you publish. It's a habit your organisation keeps when no one is watching.
Book a discovery call.
Thirty minutes, no deck. Tell us where the data hurts and we'll tell you honestly whether we're the right people — and what the first move would be.
→ hello@masteringdatamanagement.com
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