Introduction: Why the Choice of Implementation Approach Is a CIO-Level Decision
Automotive Tier1 suppliers today face several transformation pressures at once: new plants coming online to support the EV shift, legacy core systems approaching end of maintenance, and a global supply network that simply cannot afford downtime. All of these get filed under the same heading — “SAP implementation project” — yet the right way to execute varies dramatically from site to site.
TOGAF’s Architecture Development Method (ADM), specifically Phase E, “Opportunities & Solutions,” provides a framework for making this distinction explicit through three implementation approaches. The standard states:
“There are three basic approaches as follows: Greenfield: A completely new implementation. Revolutionary: A radical change (i.e., switch on, switch off). Evolutionary: A strategy of convergence, such as parallel running or a phased approach to introduce new capabilities.” (The Open Group, TOGAF Standard, Phase E)
The critical point for CIOs is that this is not merely a technical migration decision — it is a tradeoff between risk tolerance and business continuity. TOGAF itself ties this choice directly to mitigating risks identified in the Consolidated Gaps, Solutions, and Dependencies matrix. Below, we walk through three realistic scenarios a Tier1 supplier might face, and unpack why each calls for a different approach.
Scenario 1: Greenfield — Launching a New Plant in an Emerging Market
Situation
A large Tier1 supplier is standing up a new production facility in Mexico or Southeast Asia to manufacture a new part category — such as EV battery enclosures or motor housings. This is a completely new site with no existing core system, and the timeline to start of production is a tight 18 months.
Why This Approach Was Chosen
TOGAF® defines Greenfield as “a completely new implementation.” There is no legacy estate to migrate and no existing process constraints to accommodate. The CIO’s question here is not “what do we carry forward?” but “how purely can we apply the global template?” — exactly the condition under which Greenfield delivers the most value. Because there is no need to consider parallel operation or gradual convergence with an existing system, decision-making speed is maximized.
Concrete Rollout Pattern
The corporate SAP S/4HANA template (Public Cloud or Private Cloud edition) is deployed to the new site with minimal customization. Master data governance is designed from a blank slate using SAP Master Data Governance (MDG). SAP goes live in step with the start of production, and because legacy compatibility is a non-issue, the team can build primarily on standard functionality even within the compressed timeline.
Scenario 2: Revolutionary (Big Bang) — Cutting Over a Single Aging Site
Situation
A mid-sized parts plant has been running SAP ECC 6.0 for years. As ECC’s end of mainstream maintenance approaches, headquarters must prioritize this single site for migration to S/4HANA within a constrained budget and limited resources. The plant’s processes are relatively simple, and its integration with other systems is limited.
Why This Approach Was Chosen
TOGAF® defines Revolutionary as “a radical change (i.e., switch on, switch off).” This site is small enough to manage as a single cutover, but there is no appetite — or budget — to run two systems in parallel. A clear cutover window also exists, such as a year-end production shutdown, during which downtime is acceptable. Choosing a phased approach here would only introduce the cost and risk of dual operation without a corresponding benefit, given the plant’s limited complexity.
Concrete Rollout Pattern
Using a brownfield conversion approach, existing ECC data and configuration are converted directly into S/4HANA. Data cleansing and multiple mock migrations are performed in advance, and on a designated weekend, the legacy system is shut down completely; the new system is live when operations resume the following Monday. Headquarters runs a hypercare team immediately after cutover to resolve early issues.
Scenario 3: Evolutionary — A Phased, Wave-Based Global Rollout
Situation
A global Tier1 supplier with more than 15 plants across North America, Europe, and Asia is running a patchwork of legacy ERPs and local systems, and is migrating toward a unified SAP global template. Every site carries just-in-time supply obligations to automotive OEMs, and no production interruption is acceptable anywhere.
Why This Approach Was Chosen
TOGAF® defines Evolutionary as “a strategy of convergence, such as parallel running or a phased approach to introduce new capabilities.” In this multi-site, multi-system environment, a single cutover (Revolutionary) carries unacceptable supply risk, and treating each site as a blank slate (Greenfield) ignores the real constraints each one carries. The CIO’s real challenge is not “finish the template in one shot” but “converge without ever stopping supply, while feeding lessons from each wave into the next” — which is precisely what Evolutionary is designed for.
Concrete Rollout Pattern
The global template is first built and validated at headquarters together with a pilot plant (Wave 1). Subsequent waves roll out by region — North America, then Europe, then Asia (Wave 2, Wave 3, and beyond). At each site, the legacy ERP and SAP run in parallel for a defined period to validate data integrity and process behavior before the legacy system is retired. In some cases, this is combined with a function-by-function phasing — procurement and inventory first, then production planning, then quality management. The template itself improves with each wave, accelerating rollout speed at later sites.
Three Decision Criteria Every CIO Should Apply
Comparing the three scenarios above, the choice of approach comes down to three questions:
- Does legacy exist? Does the target site carry legacy systems or existing process constraints? If not, Greenfield becomes a viable candidate.
- How much downtime can the business tolerate? Based on the Business Transformation Readiness Assessment, how much temporary disruption can the site absorb? High tolerance points toward Revolutionary; low tolerance points toward Evolutionary.
- How complex are cross-site dependencies? How entangled is the site with other plants and adjacent systems — MES, quality management, supplier portals? Higher complexity favors an Evolutionary approach that spreads risk across waves.
Conclusion: A Blended Strategy, Not a Single Approach
For a globally distributed Tier1 automotive supplier, these three approaches are rarely an either-or choice — in practice, they are combined according to site characteristics. New sites are standardized rapidly through Greenfield; manageable existing sites capture the moment through Revolutionary cutovers; and multi-site rollouts carrying supply obligations converge carefully through Evolutionary waves. The CIO’s task is to map each site against these three decision criteria and integrate the resulting choices into a single, coherent global rollout plan.
Sources
- The Open Group, “TOGAF® Standard, Version 9.1 — Phase E: Opportunities & Solutions,” https://pubs.opengroup.org/architecture/togaf91-doc/arch/chap13.html
Disclaimer
Parts of this article were developed with reference to generative AI suggestions and were reviewed, refined, and supplemented based on the author’s professional expertise and judgment.
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