The ICMG Enterprise Anatomy™ Model Is Not an EA Maturity Ladder. It Is a EA Convergence Model

Most Enterprise Architecture “maturity models” measure capability. They describe whether an organisation has EA activities, governance forums, standards, repositories, tooling, and whether those activities appear more consistent over time. This is a useful lens for assessing the presence of EA practice.

But it is not the lens ICMG Enterprise Anatomy™ uses.

The ICMG Enterprise Anatomy™ model does not measure how mature your EA practice looks. It measures something else entirely: the degree to which enterprise anatomy becomes one. 

In other words, it measures how many independent “anatomies” are operating inside the organization, and whether those anatomies converge into one governing anatomy.

That is why it is not another maturity ladder. It is a convergence model.

Why “maturity” language breaks the interpretation

Traditional maturity models assume a single axis: capability increases from low to high. The organization is judged as moving from “less mature” to “more mature” based on whether more EA activities exist and whether they are executed consistently.

ICMG’s model does not operate on that axis.

The question in the ICMG model is not: How mature is your EA function?

The question is: How converged is your anatomy?

This changes the object being measured. Traditional models measure the maturity of an activity. ICMG measures the convergence of an anatomical reality.

The core distinction: capability progression vs anatomical convergence

Traditional maturity models follow this mental model:

Low capability → higher capability → high capability

ICMG’s model follows a different mental model:

Many anatomies → fewer anatomies → one governing anatomy

This is not semantic. It is anatomical.

The ICMG model is identifying whether the enterprise is operating with one shared internal anatomy or with many parallel anatomies, each reinvented by projects, departments, or programs.

What “convergence” means in enterprise terms

Anatomy exists everywhere in an enterprise whether it is explicit or not. Every department, initiative, and program already runs on some internal logic of strategy, process sequencing, rules, data boundaries, component choices, implementation patterns, and operations.

When anatomy is implicit, each unit reinvents these definitions. The organization therefore operates with multiple competing anatomies.

That is what creates drift: different approvals behave differently, exceptions expand, rule interpretations diverge, and operational behavior becomes unpredictable.

Convergence means moving from that fragmented state to a state where the enterprise behaves as one system because one anatomy governs how initiatives behave.

That is why the ICMG model defines maturity as a series of “One Anatomy” rules.

The four convergence levels in the ICMG model

Each level answers one question: what becomes one at this level?

Level 1 — EA (IT): One IT Anatomy

Many IT projects → one IT anatomy

Level 1 is not a statement that EA exists in the enterprise. It is a statement that anatomy convergence has occurred inside IT.

The invariant at this level is simple and measurable: all IT projects follow one common IT anatomy. If there are 100–160 IT initiatives, each project instantiates the same internal anatomy rather than inventing its own.

What exists at this level is the P1–P4 anatomy of IT:

P1: IT Strategy, P2: IT Processes, P3: IT Logic (rules, sequencing, controls), P4: IT Components (applications, platforms, infrastructure)

The evidence rule is the key: if the organisation has 160 IT projects and each behaves as an instantiation of the same anatomy, then IT anatomy has converged. If each project recreates its own patterns—even when tool stacks are uniform—then Level 1 convergence does not exist.

The boundary is equally important. Level 1 convergence is confined to IT. Business departments remain external. The CIO can own Level 1 convergence. The enterprise cannot claim enterprise anatomy convergence at Level 1.

This is why Level 1 is the maximum level most organizations can realistically claim today.

And even here, many confuse vendor standardization with anatomy convergence.

Level 2 — EA (Departments / Functions): One Department One Anatomy™

Many initiatives in a department → one department anatomy

Level 2 is the first major elevation beyond IT. The invariant at this level is that all initiatives within a department follow one department anatomy.

This is anatomical consistency claim.

Each department has a complete P1–P6 anatomy:

P1: Strategy, P2: Process, P3: Systems / Logic, P4: Components, P5: Implementation, P6: Operations

The consistency rule is explicit. If Sales has 20 initiatives, all 20 must follow the same Sales strategy logic, the same process structure, the same systems and rule logic, and the same operational model.

This becomes:

20 Sales initiatives → one Sales anatomy 15 departments → 15 anatomies

At Level 2, departmental use cases become governable anatomically: sales use cases, HR use cases, finance use cases, procurement use cases, operations use cases. Each is governed by its department anatomy rather than ad-hoc program logic.

This level achieves departmental consistency and eliminates project-specific reinvention inside functions. It creates traceability from intent to operations within each department.

But the model is also explicit about its limitation. At Level 2, anatomies remain department-centric. Cross-department coordination still relies on negotiation. The enterprise does not yet behave as one system because anatomies have not converged across departments.

Level 3 — EA (Industry / Enterprise): One Industry One Anatomy™

All departments → one enterprise anatomy

This is where Enterprise Architecture becomes enterprise-level in the ICMG sense.

The invariant at this level is that all departments operate inside one shared industry anatomy. The 15 departmental anatomies integrate. A single P1–P6 enterprise anatomy governs the enterprise as one organism.

At this level, decisions stop being department-optimized. The enterprise operates with one governing anatomy for enterprise-wide trade-offs. This is the point where anatomy begins to govern real decisions in real time, because that is what convergence implies.

This is also why “application of anatomy” is not a separate Level 5. If Level 3 convergence exists, enterprise decisions necessarily follow the unified anatomy. Use cases are intrinsic to Level 3: investment decisions, regulatory sequencing, scaling and capacity planning, service reliability, and cost and performance trade-offs are governed through one enterprise anatomy.

Level 3 is rare in practice because it removes discretionary overrides across silos. It requires departments to stop running independent anatomies under enterprise branding.

Level 4 — EA (Advanced Anatomy Model): Variable-Rich Anatomy

All decisions → one variable-rich anatomy

Level 4 does not widen scope. It deepens anatomy.

The difference is precise: Level 3 means P1–P6 exists and governs decisions. Level 4 means each P1–P6 is parameterized. P1–P6 becomes supported by internal variables (as defined in the model), so anatomy becomes computable.

This enables predictive analysis, scenario simulation, and stress testing across capacity, energy, cost, and resilience. Anatomy becomes reusable across planning cycles because it is no longer only explicit; it is operationalized through variables.

Level 4 is therefore convergence at a deeper layer: convergence of decision variables into one computable anatomy.

The “One Anatomy” rules are the model

The simplest expression of the model is the consistency pattern:

L1: All IT projects → one IT anatomy

L2: All initiatives per department → one department anatomy

L3: All departments → one enterprise / industry anatomy

L4: All decisions → one variable-rich anatomy

This is why the model is structurally sound. Each level is defined by a convergence rule, not by maturity descriptions.

Why the ICMG model cannot be confused with Gartner & Others

Gartner-style maturity models measure the maturity of EA activities. They assess whether an organization has EA artifacts, processes, governance, and adoption.

ICMG measures the maturity of anatomical convergence. It assesses whether one governing anatomy exists and whether it is shared, explicit, and used.

These models do not compete because they do not measure the same object. They do not intersect because they do not sit on the same axis.

The practical implication of calling it a convergence model

ICMG EA Maturity as a convergence model.

That is the difference between “EA maturity” as the market uses the term and “Enterprise Anatomy maturity” as ICMG defines it.

The ICMG Enterprise Anatomy™ model is therefore not asking whether EA exists. It is asking whether the enterprise is operating as one organism — because one anatomy governs it.

ICMG Enterprise Anatomy™ Maturity & Certification — Integrated View

(EA as elevation into Enterprise Anatomy)

Level	Focus	“One Anatomy” Rule	What Exists	Propagation Logic	What Certification Confirms
Level 1 — EA (IT)	IT anatomy	Many IT projects → One IT Anatomy™	Full P1–P6 IT anatomy governing strategy, process, logic, components, implementation, operations	1 project → 10 → 100 → entire IT portfolio inherits same anatomy	One IT anatomy exists and governs decisions across IT initiatives
Level 2 — EA (Departments)	Department anatomy	Sub-functions → One Department Anatomy™	Each department (HR, Sales, Finance, etc.) has P1–P6 anatomy including manual + IT work	One sub-function → multiple sub-functions → full department convergence	Department initiatives instantiate one shared anatomy consistently
Level 3 — EA (Enterprise / Industry)	Enterprise anatomy	Departments → One Enterprise Anatomy™	15 departmental anatomies integrated into shared enterprise structure	1 enterprise initiative → 5–10 → 50+ enterprise-wide initiatives follow shared anatomy	Enterprise initiatives propagate one integrated P1–P6 anatomy across departments
Level 4 — Advanced Enterprise Anatomy™	Variable-rich anatomy	Decisions → One Computable Anatomy™	Each P1–P6 refined using six variables (rules, network, data, roles, activities, timing)	One department refined → multiple departments → enterprise-wide variable-rich anatomy	Anatomy becomes precise, parameterized, and decision-predictive

How to Read This Model

Traditional EA maturity models measure how architecture is practiced.

ICMG Enterprise Anatomy™ maturity measures:

how many separate anatomies exist — and how far convergence toward one anatomy has progressed.

Each level represents a shift from:

1. isolated interpretation → shared anatomy,

2. project-specific design → anatomical propagation,

3. coordination → governing anatomy.

Core Progression

• Level 1 stabilizes IT behavior.

• Level 2 stabilizes departmental behavior.

• Level 3 stabilizes enterprise behavior.

• Level 4 makes anatomy precise enough for predictive decision-making.