Martenweave journal

Practical notes for model work that has to survive delivery.

141 articles on SAP migration, MDM and MDG delivery, data governance, logistics, lineage, impact, and deterministic validation.

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SAP MDG and MDMSAP MDG Manages Master Data. Who Manages the Implementation Knowledge?

SAP Master Data Governance can manage governed records, change requests, workflows, data quality rules and the operational lifecycle of master data.

14 July 2026 · 14 min read Migration readinessWhy SAP Migration Mapping Spreadsheets Break Down

Most SAP migration programmes begin with a mapping spreadsheet.

14 July 2026 · 16 min read SAP MDG and MDMWhat to Prepare Before Starting an SAP MDG Implementation

An SAP MDG implementation often appears to begin with the platform.

14 July 2026 · 21 min read SAP MDG and MDMHow SAP Data Migration and MDG Implementation Should Work Together

SAP data migration and SAP Master Data Governance are often organised as separate workstreams.

14 July 2026 · 17 min read SAP MDG and MDMWhy an SAP MDG Implementation Needs an Independent Model Specification

An SAP MDG implementation contains several versions of the model.

14 July 2026 · 20 min read Migration readinessSAP Data Migration Readiness Checklist

A migration team can complete mappings, build load files and pass several technical checks while the domain is still not ready for migration.

14 July 2026 · 21 min read Migration readinessWhy Mapping Completion Is Not Migration Readiness

A migration programme reports that 96% of mappings are complete.

14 July 2026 · 18 min read Migration readinessHow to Build a Single Source of Truth for SAP Mappings

Most SAP programmes claim to have a single source of truth for mappings.

14 July 2026 · 19 min read Validation and readinessHow to Detect Dataset Gaps Before SAP Migration Testing

Many SAP migration programmes treat testing as the first serious encounter between the target model and the source data.

14 July 2026 · 23 min read Lineage and impactHow to Perform Impact Analysis for an SAP Field Change

On Monday, a country team asks for one SAP field to become mandatory.

14 July 2026 · 20 min read Lineage and impactHow to Trace a Legacy Field to an SAP Target Field

A defect appears during the second mock load.

14 July 2026 · 18 min read SAP MDG and MDMHow to Keep SAP MDG Design and Configuration Aligned

The design document says the field is optional.

14 July 2026 · 19 min read SAP MDG and MDMHow to Reduce Rework During an SAP MDG Implementation

The programme has already approved the model.

14 July 2026 · 20 min read SAP MDG and MDMWhat an SAP MDG Handover Package Should Contain

The SAP MDG programme goes live on Friday.

14 July 2026 · 22 min read Model governanceWhy Project Knowledge Disappears After Go-Live

Six months after go-live, an SAP MDG validation starts rejecting supplier changes.

14 July 2026 · 21 min read SAP MDG and MDMHow Martenweave Complements SAP MDG

A company has already invested in SAP Master Data Governance.

14 July 2026 · 18 min read Model governanceMartenweave vs Excel, Jira and Confluence

The programme already has an approved toolset.

14 July 2026 · 21 min read Model governanceData Model Registry vs MDM Platform

A company has a data problem.

14 July 2026 · 23 min read Model governanceData Model Registry vs Data Catalog

A migration manager searches the enterprise data catalogue for a customer field.

14 July 2026 · 21 min read AI governanceWhy AI Should Propose Model Changes but Never Apply Them Directly

An AI agent reviews a migration workbook and finds an obvious inconsistency.

14 July 2026 · 21 min read Validation and readinessHow Deterministic Validation Reduces Migration Risk

The migration workbook looks complete.

14 July 2026 · 22 min read SAP MDG and MDMHow to Manage Global and Local Requirements in SAP MDG

The global template says the field is mandatory.

14 July 2026 · 22 min read SAP MDG and MDMHow to Track SAP MDG Model Decisions

During a design workshop, the programme agrees that a supplier classification should be mandatory.

14 July 2026 · 19 min read SAP MDG and MDMHow to Validate That SAP MDG Configuration Matches the Approved Model

The design review is complete.

14 July 2026 · 20 min read Migration readinessHow to Build an Evidence-Based Migration Readiness Report

The steering committee sees a green dashboard.

14 July 2026 · 22 min read Lineage and impactHow Better Model Traceability Reduces Rework

A migration defect appears during UAT.

14 July 2026 · 19 min read Model governanceHow to Reduce Key-Person Risk in SAP Programmes

The programme has one person who knows how everything fits together.

14 July 2026 · 23 min read SAP MDG and MDMHow Much of an MDG Programme Happens Outside the MDG Platform?

The programme has selected SAP Master Data Governance.

14 July 2026 · 22 min read SAP MDG and MDMHow a Small Martenweave Pilot Can De-Risk a Large MDG Investment

The organisation is preparing a major SAP Master Data Governance programme.

14 July 2026 · 21 min read AMS and continuityHow Metalhatscats Helps Teams Establish Model Governance

A programme has already created most of the artefacts it needs.

14 July 2026 · 20 min read AMS and continuityHow to Turn Model Governance into an AMS Capability After Go-Live

The implementation programme has ended.

14 July 2026 · 22 min read Model governanceHow to Use GitHub as a Change-Control Layer for SAP Data Models

A country team changes one row in a mapping workbook.

14 July 2026 · 21 min read Model governanceHow to Govern Spreadsheet Changes Without Forcing Business Users into Git

The business owner receives a mapping workbook.

14 July 2026 · 21 min read AMS and continuityHow to Design a Model Change Request That Business and Technical Teams Can Review Together

A business owner requests a change:

14 July 2026 · 23 min read Model governanceHow to Prioritise Model Changes by Business Risk Instead of Ticket Urgency

A senior stakeholder opens a ticket:

14 July 2026 · 22 min read SAP MDG and MDMHow to Build a Model Risk Register for SAP Migration and MDG

The programme risk register looks healthy.

14 July 2026 · 23 min read Migration readinessHow to Turn Model Risks into an Actionable SAP Migration Backlog

The migration programme has identified a serious risk:

14 July 2026 · 20 min read Migration readinessHow to Define Exit Criteria for SAP Migration Model Risks

The programme has completed the remediation task.

14 July 2026 · 23 min read Migration readinessHow to Prove That an SAP Migration Risk Is Really Closed

The steering committee asks whether a critical migration risk has been closed.

14 July 2026 · 21 min read SAP MDG and MDMHow to Design a Closure Evidence Workspace for SAP Migration and MDG

The programme is preparing for a risk-closure meeting.

14 July 2026 · 20 min read Model governanceHow to Connect Martenweave’s UI to Live Model, Dataset and Proposal Data

A migration architect opens Martenweave and searches for Customer Group .

14 July 2026 · 21 min read Model governanceHow to Investigate an SAP Data Model Problem Before Changing the System

A migration test fails because Customer Group is missing.

14 July 2026 · 24 min read Validation and readinessHow to Structure a Model Investigation Case So the Finding Can Be Reused

The German migration team spends three weeks investigating why Customer Group cannot be mapped reliably.

14 July 2026 · 18 min read Migration readinessHow to Build a Reusable Decision Library for SAP Migration and MDM

A programme has an approved decision:

14 July 2026 · 20 min read Model governanceHow to Prevent Local SAP Decisions from Fragmenting the Global Data Model

A country team raises a reasonable request.

14 July 2026 · 22 min read Model governanceHow to Decide Whether a Local SAP Requirement Belongs in the Global Model

A country team requests a new field:

14 July 2026 · 24 min read Model governanceHow to Design Global and Local Model Inheritance Without Creating Configuration Chaos

The global supplier model defines Supplier Risk as a mandatory final classification for active strategic suppliers.

14 July 2026 · 19 min read Model governanceHow to Resolve Conflicting Global and Local Rules Before They Reach SAP Configuration

The global design states:

14 July 2026 · 18 min read Migration readinessHow to Test Global and Local SAP Rules Against Real Migration Data

The global design says that Supplier Risk is mandatory for every active strategic supplier.

14 July 2026 · 21 min read Migration readinessHow to Turn Migration Rule Test Results into Model Decisions Instead of Defect Noise

The first migration-rule test produces 8,420 failures.

14 July 2026 · 22 min read Validation and readinessHow to Build a Migration Finding Taxonomy That Business, Data and SAP Teams Use Consistently

The migration test reports that 4,860 supplier records failed the Tax Identifier rule.

14 July 2026 · 23 min read Validation and readinessHow to Route Migration Findings to the Right Owner Without Creating Another Governance Bureaucracy

A migration-readiness run identifies 1,284 strategic suppliers without Supplier Risk.

14 July 2026 · 19 min read Model governanceHow to Define Data Ownership That Still Works After the SAP Programme Ends

Three months after go-live, an AMS analyst receives an incident.

14 July 2026 · 18 min read AMS and continuityHow to Build an AMS Model Change Process That Does Not Recreate the SAP Project

Six months after go-live, a country requests a new Supplier Classification value.

14 July 2026 · 20 min read Lineage and impactHow to Separate SAP AMS Incidents, Service Requests and Model Changes Without Losing Traceability

A user reports that a supplier cannot be activated in SAP.

14 July 2026 · 18 min read AMS and continuityHow to Detect When an SAP AMS Workaround Has Become an Unapproved Data Model

A supplier cannot be activated because its final risk classification is missing.

14 July 2026 · 24 min read AMS and continuityHow to Retire SAP AMS Workarounds Without Breaking the Business Process

A temporary Supplier Risk workaround has been running for nine months.

14 July 2026 · 21 min read AMS and continuityHow to Use AMS Incident Patterns to Improve the SAP Data Model Instead of Just Reducing Ticket Volume

The AMS dashboard shows progress.

14 July 2026 · 23 min read Model governanceHow Martenweave Represents a Data Model in Markdown and YAML

A migration team needs to confirm the meaning of Customer Group .

14 July 2026 · 20 min read AI governanceWhy Canonical Model Files Should Remain the Source of Truth

A business owner updates Customer Group in an Excel review file.

14 July 2026 · 20 min read Model governanceHow Martenweave Builds a Searchable SQLite Model Index

A migration analyst searches for:

14 July 2026 · 22 min read Validation and readinessHow Deterministic Model Validation Works

A migration analyst adds a new mapping:

14 July 2026 · 24 min read Model governanceHow Martenweave Represents Entities, Attributes, Rules and Relationships

A migration workbook contains one row:

14 July 2026 · 21 min read Model governanceHow to Version a Data Model Without Turning It into Documentation Chaos

A Customer Group rule changes during an SAP programme.

14 July 2026 · 23 min read Model governanceHow Model Diffing Should Work Across SAP Releases

An SAP programme compares its Wave 2 and Wave 3 model repositories.

14 July 2026 · 19 min read Model governanceHow to Design Stable IDs for Enterprise Data Model Objects

A Customer Group attribute begins its life in one migration workbook.

14 July 2026 · 23 min read Model governanceWhy Generated Indexes Should Be Disposable

A Martenweave user opens modelops.db and corrects the name of an Attribute directly in SQLite.

14 July 2026 · 23 min read Model governanceHow to Package and Transfer a Martenweave Model Repository

An SAP migration programme reaches handover.

14 July 2026 · 21 min read Lineage and impactHow to Build Field-Level Lineage for an SAP Migration

A migration programme says that it has lineage.

14 July 2026 · 20 min read Lineage and impactWhy Table-Level Lineage Is Not Enough for Master Data

A migration architect opens the lineage view and sees:

14 July 2026 · 17 min read Lineage and impactHow to Trace a Business Attribute Across Source Systems, Mappings and SAP Fields

A business owner asks:

14 July 2026 · 17 min read Lineage and impactHow to Calculate Downstream Impact Before Changing an SAP Field

A technical team proposes a simple change:

14 July 2026 · 20 min read Lineage and impactHow Impact Analysis Should Work for Rules, Mappings and Value Lists

A team proposes three changes:

14 July 2026 · 20 min read Migration readinessHow to Detect Orphaned Fields, Rules and Mappings

A repository validates successfully.

14 July 2026 · 27 min read Lineage and impactHow to Detect Broken Lineage After a Source or Target System Change

A source system is retired.

14 July 2026 · 20 min read Lineage and impactHow to Model Source Authority and Fallback Paths Without Creating Ambiguous Lineage

A migration team traces Customer Group upstream and finds four possible sources:

14 July 2026 · 22 min read Lineage and impactHow to Separate Design-Time Lineage from Runtime Evidence

A migration design states:

14 July 2026 · 21 min read Lineage and impactHow to Use Lineage Evidence During Mock Loads, Cutover and Hypercare

Lineage is often treated as design documentation.

14 July 2026 · 20 min read Lineage and impactHow to Build a Lineage-Based Migration Readiness Score Without Hiding Risk

A migration dashboard shows:

14 July 2026 · 21 min read Lineage and impactHow to Explain Lineage and Impact to Business Owners Without Showing Them a Graph Database

A data architect opens a lineage viewer during a business review.

14 July 2026 · 23 min read Lineage and impactHow Lineage Supports AMS Root-Cause Analysis After Go-Live

A production incident arrives in the AMS queue:

14 July 2026 · 22 min read Lineage and impactHow to Connect Dataset Gaps to Lineage and Business Impact

A dataset-readiness report says:

14 July 2026 · 20 min read Migration readinessHow to Prioritize Migration Gaps by Business Risk Instead of Field Count

A readiness report identifies 137 data gaps.

14 July 2026 · 23 min read Validation and readinessHow to Turn Migration Gap Findings into Reviewable Patch Proposals

A profiling script finds that the Product migration dataset has no Plant field.

14 July 2026 · 26 min read AI governanceWhy AI Should Propose Model Changes but Never Approve Them

A Product migration dataset contains PLANNER GROUP , MRP TYPE and PROCUREMENT TYPE .

14 July 2026 · 18 min read Migration readinessWhy a Data Catalogue Is Not Enough for Migration Model Governance

A migration team is preparing Product data for SAP S/4HANA.

14 July 2026 · 16 min read SAP MDG and MDMWhy SAP MDG Is Not a Replacement for a Migration Model Registry

A programme is migrating Supplier bank data into SAP S/4HANA.

14 July 2026 · 17 min read SAP MDG and MDMHow Martenweave Should Work Alongside SAP MDG During a Migration

A programme is migrating Supplier bank data from several legacy systems into SAP S/4HANA.

14 July 2026 · 17 min read Migration readinessWhy Migration Mapping Workbooks Become Technical Debt—and What Should Replace Them

A migration programme creates a mapping workbook for Product planning data.

14 July 2026 · 17 min read Migration readinessHow We Convert a Mapping Workbook into a Canonical Model Without Losing Business Context

When we receive a migration mapping workbook, our first instinct should not be to convert every row into YAML.

14 July 2026 · 17 min read Lineage and impactHow We Keep Business Decisions Traceable After the Mapping Workbook Is Gone

A migration team decides that MRP Controller must be derived differently for Plant PL30.

14 July 2026 · 14 min read Migration readinessHow We Prevent Temporary Migration Exceptions from Becoming Permanent Rules

During Mock Load 2, the Product planning migration has a coverage problem.

15 July 2026 · 15 min read Validation and readinessHow We Model Data Quality Rules Without Mixing Business Policy and Technical Validation

A migration programme is preparing Supplier bank data for SAP.

15 July 2026 · 17 min read Validation and readinessHow We Turn Validation Failures into Actionable Findings Instead of Another Error Report

We run a validation against a Supplier bank-data migration dataset.

15 July 2026 · 18 min read Validation and readinessHow We Decide Whether a Finding Requires Data Correction, a Mapping Change or a Model Change

A Supplier bank-data validation fails for 3,400 records.

15 July 2026 · 19 min read Lineage and impactHow We Prioritize Findings by Business Impact Instead of Error Count

We complete a Supplier bank-data validation run.

15 July 2026 · 18 min read Validation and readinessHow We Prevent Duplicate Findings Across Mock Loads and Migration Waves

We run the Supplier bank-verification check during Mock Load 2.

15 July 2026 · 16 min read Validation and readinessHow We Connect Findings to Owners Without Building Another Workflow Engine

We confirm a critical Supplier bank-data Finding.

15 July 2026 · 18 min read Validation and readinessHow We Prove That a Finding Is Actually Resolved

We identify a critical Supplier bank-data Finding.

15 July 2026 · 19 min read Model governanceHow We Detect When Evidence Has Become Stale

We resolve a critical Supplier bank-data Finding during Cutover Rehearsal 5.

15 July 2026 · 17 min read Migration readinessHow We Build a Migration Readiness View That Does Not Hide Exceptions

The Supplier migration dashboard shows:

15 July 2026 · 20 min read Model governanceHow We Separate Technical Completeness from Business Readiness

A Supplier migration load finishes successfully.

15 July 2026 · 18 min read Migration readinessHow We Use Model Evidence During Cutover Approval

The Supplier migration team completes the final rehearsal.

15 July 2026 · 15 min read Logistics dataWhy a Successfully Loaded Material May Still Be Unusable

The material migration report looks successful.

15 July 2026 · 16 min read Logistics dataHow We Detect Missing Material Extensions Before Cutover

The material migration team reports:

15 July 2026 · 15 min read Logistics dataWhy Units of Measure Are One of the Most Dangerous Logistics Migration Objects

The unit-of-measure migration report looks harmless.

15 July 2026 · 16 min read Logistics dataHow We Model Packaging Hierarchies Without Losing Logistics Meaning

The material migration team reports that packaging data is complete.

15 July 2026 · 17 min read Logistics dataWhy S/4 Material Readiness Does Not Prove EWM Readiness

The material migration dashboard is green.

15 July 2026 · 16 min read Logistics dataHow We Create a Canonical Location Model Across ERP, EWM, TM and External Carriers

What happens when five systems agree that a location exists—but none of them agrees on what the location actually is?

15 July 2026 · 18 min read Logistics dataHow We Govern Lead Times Across Procurement, Production, Warehouse and Transportation

What exactly are we promising when we say the lead time is 12 days?

15 July 2026 · 17 min read Model governanceWhy SAP Data Programmes Pay Consultants to Rediscover the Same Knowledge

Why are we paying senior consultants to answer the same question for the fourth time?

15 July 2026 · 17 min read Lineage and impactHow a Canonical Data and Interface Registry Reduces Change-Impact Consulting Costs

Why can changing one master-data field require six weeks of analysis?

15 July 2026 · 15 min read Migration readinessWhy Mapping Workbooks Become a Recurring Consulting Cost

How many times should a transformation programme pay to map the same 1,400 legacy codes?

15 July 2026 · 17 min read Model governanceHow Much Does a Green Dashboard Cost When Every Team Rebuilds the Evidence Behind It?

How much consulting effort sits behind one green status on a steering-committee slide?

15 July 2026 · 17 min read Model governanceWhy Consultant Turnover Makes SAP Programmes Pay Twice for the Same Knowledge

What exactly leaves the programme when an experienced consultant leaves?

15 July 2026 · 17 min read Logistics dataWhere Martenweave Fits in Logistics: Managing the Data Behind Operations

Logistics problems are often described as operational problems.

15 July 2026 · 9 min read Logistics dataLogistics Problems Rarely Start in Logistics

When a delivery fails, people usually look at the delivery.

15 July 2026 · 10 min read Logistics dataSAP Logistics Data Migration Problems Usually Appear Too Late

Most SAP logistics migration problems are discovered at the worst possible moment.

15 July 2026 · 11 min read Model governanceWhat Is a Data Model Registry? A Practical Guide for Managers

Most companies do not lack documentation.

15 July 2026 · 14 min read Migration readinessWhy Data Migration Projects Need a Model Registry

Most migration programmes do not fail because nobody created a mapping.

15 July 2026 · 12 min read Migration readinessFrom Mapping Spreadsheet to Governed Data Model

Most migration programmes begin with a spreadsheet.

15 July 2026 · 12 min read Lineage and impactData Lineage vs Impact Analysis: Why Seeing the Flow Is Not Enough

Data lineage is one of the most attractive ideas in data management.

15 July 2026 · 15 min read Validation and readinessData Quality Tools vs Model Validation: Clean Data Can Still Follow the Wrong Rules

A data-quality report can be completely green while the migration is still wrong.

15 July 2026 · 16 min read Model governanceSchema Registry vs Model Registry: Technical Compatibility Is Not Business Meaning

A message can be technically valid and still be wrong.

15 July 2026 · 14 min read AMS and continuityWhy SAP Migration Teams Still Lose Control Even with the Right Tools

An SAP migration programme may have every major tool it is supposed to have.

15 July 2026 · 15 min read AMS and continuityMapping Version Drift: Why SAP Migration Teams Keep Reopening the Same Decisions

Most migration teams believe they have a mapping problem only when a field is missing.

15 July 2026 · 11 min read Migration readinessSAP Migration TCO: How Model Governance Reduces Rework and Project Cost

The licence fee is rarely the most dangerous part of migration cost.

15 July 2026 · 14 min read Model governanceWhy Martenweave Creates More Value Across a Programme Than in a Single Project

A small migration project may not need Martenweave.

15 July 2026 · 13 min read Model governanceWhy Data Governance Frameworks Stay on Paper During SAP Programmes

Many organisations already know what good data management should look like.

15 July 2026 · 17 min read AMS and continuityWhy DAMA-Based Data Governance Fails to Reach SAP Migration Teams

Many companies have a data-governance framework.

15 July 2026 · 17 min read Model governanceMartenweave vs Collibra, Alation, and Atlan: A Model Registry Is Not a Data Catalog

A migration architect is asked a fair question: “We already have a catalogue. Why are mappings, rules, and exceptions still in workbooks?”

18 July 2026 · 4 min read Model governanceMartenweave vs OpenMetadata and DataHub: Open Source Does Not Mean the Same Scope

An architect who wants open source may see OpenMetadata, DataHub, and Martenweave in the same search results and assume they are interchangeable. They are not.

18 July 2026 · 4 min read Model governanceMartenweave vs Informatica, Semarchy, Reltio, and Profisee: Model Evidence vs Operational Mastering

When a programme needs a trusted customer, supplier, product, or location record in production, it should not mistake a documentation tool for an MDM platform.

18 July 2026 · 3 min read Model governanceMartenweave vs Microsoft Purview: Enterprise Governance Context and Delivery Model Control

Microsoft-centric organisations often ask whether a separate model registry is necessary once Microsoft Purview is in place. The honest answer is sometimes no.

18 July 2026 · 3 min read Model governanceMartenweave Alongside SAP Datasphere, SAP Business Data Cloud, and SAP LeanIX

SAP programmes can collect architecture information in LeanIX, semantic and analytic models in Datasphere, governed operational master data in MDG, and transformation…

18 July 2026 · 3 min read Model governanceOpen-Source Model Governance vs Proprietary Enterprise Platforms

The question is not whether open source is inherently safer, cheaper, or more flexible. Those claims depend on the team, the operating model, and the product category.

18 July 2026 · 3 min read Model governanceBuild, Buy, or Extend: Choosing a Model-Governance Approach

The wrong model-governance decision usually begins with a false choice: buy a big platform or keep using spreadsheets. There is a third path—extend a controlled, sourc…

18 July 2026 · 3 min read Model governanceWhen Martenweave Is the Wrong Tool

Good product evaluation includes an exit ramp. Martenweave is useful when a team needs a canonical, inspectable model and evidence layer around a bounded delivery prob…

18 July 2026 · 3 min read Model governanceExtending Martenweave with Project Modules and Domain Packs

A generic model registry becomes useful only when it can represent the distinctions that make a programme difficult. In SAP migration, a field is rarely just a field:…

18 July 2026 · 3 min read Model governanceHow Consulting Teams Can Reuse SAP Migration Knowledge Without Reusing Client Data

Consulting teams usually know the questions that cause a programme to stall: Which source is authoritative? Does a sales-area attribute apply to every customer? What p…

18 July 2026 · 3 min read Model governanceMartenweave vs dbt and Custom Git Repositories: Transformation Code Is Not a Migration Model

Many data teams already version model-related work in Git. dbt projects contain SQL models, YAML properties, tests, and a dependency graph. Internal repositories conta…

18 July 2026 · 4 min read