Migrating to SAP S/4HANA represents a pivotal transformation for enterprises seeking to modernize their ERP systems. With SAP ECC support nearing its end, organizations must evaluate their options to ensure a seamless transition. However, selecting the right implementation approach is never a one-size-fits-all proposition.

Factors Influencing the Choice of Implementation

The decision depends on several factors, including:

• Company’s current SAP usage
• Deployment preferences
• Data complexity
• Future business goals.

 Three Main S/4HANA Implementation Approaches 

The primary implementation strategies available to enterprises are:

• Greenfield: Greenfield involves a complete reimplementation of SAP S/4HANA from scratch

• Brownfield: Brownfield allows companies to convert their existing SAP systems while retaining historical data and configurations

• Blue Field (Hybrid): The Hybrid approach blends elements of both.

Greenfield Implementation

The Greenfield implementation approach implements SAP S/4HANA as a completely new system. There is no carrying over of historical data, custom configurations, or dealing with legacy code. Doing it this way allows businesses to reimagine and streamline their processes, taking full advantage of SAP S/4HANA’s capabilities.

Advantages and Disadvantages of Greenfield Implementation

Following are the advantages and disadvantages of sap greenfield implementation:

Advantages	Disadvantages
Greenfield implementation remove old customizations and adopt SAP best practices.	Greenfield implementations are resource-intensive and require significant change management efforts.
Organizations can achieve lower Total Cost of Ownership (TCO) and faster Time-to-Value, by standardizing processes and leveraging pre-configured templates.	Data migration can be complex, and rebuilding critical business processes is dependent on careful planning.
Drive businesses to integrate new technologies like AI and automation seamlessly.

Deployment: On premise or in the Cloud

An on-premises deployment offers greater control as well as better security. On-premises environments also offer more customization which better serves the need with complex regulatory needs or significant customization. The downside of on-premises deployments is that they require a large upfront investment and ongoing maintenance.

Cloud deployments for SAP S/4HANA are considerably different. Cloud deployments offer scalability to go along with minimal upfront costs and quicker time-to-value. However, organizations needing customization or compliance needs may find the cloud to be inadequate for the needs.

Finally, hybrid deployments balance the stability and customization of on-premises with the flexibility of the cloud. In many cases this truly does deliver the best of both worlds.

Brownfield Implementation

The Brownfield implementation approach gives organizations the ability to migrate their existing SAP ERP system to S/4HANA without abandoning existing configurations, customizations, and historical data. This method is perfect for companies that want to minimize disruptions in favor of keeping things running smoothly.

Advantages and Disadvantages of Brownfield Implementation

Advantages	Disadvantages
Businesses can upgrade their workflows to SAP S/4HANA through system conversion. This also lets them rethink old processes.	Brownfield implementation can limit innovation too. It brings along old inefficiencies and technical debt.
Significantly reduces implementation time and costs compared to a full Greenfield reimplementation	Additionally, the success of the implementation depends on how well existing workflows integrate with the new S/4HANA environment.
Retaining existing configurations makes for a smoother transition, making it easier for employees to adapt to the new system.	For companies with heavily customized legacy systems, technical issues can come up. This may require a lot of testing and fixes.

Ideal Scenario for Choosing Brownfield Implementation

The ideal scenario for the Brownfield approach is for customers seeking rapid conversion from SAP ECC to S/4HANA while they use their current solutions.

Steps in Brownfield Implementation

The Brownfield implementation approach is a structured process that begins with preparation and assessment, wherein businesses conduct system readiness checks, analyze custom code, and evaluate infrastructure requirements. The conversion phase involves migrating the database to SAP HANA and updating the system using SAP’s Software Update Manager (SUM). Once the technical implementation is complete, a wide range of comprehensive testing is conducted.

Testing includes:

• Unit testing
• Integration testing
• User Acceptance Testing, or “UAT”
• Performance testing
  

Finally, businesses transition to live operations with comprehensive end-user training, go-live execution, and post-implementation support. After the implementation, it is time for ongoing monitoring and performance optimization.

Brownfield+: Enhanced Brownfield Approach

For companies that want to keep parts of their SAP system while upgrading, the Brownfield+ approach combines AI and automation to ease the implementation process. This enhanced methodology helps reduce technical debt, accelerates transformation, and provides deeper business insights.

Benefits of Brownfield+ Implementation Approach

By integrating intelligent automation and advanced SAP toolsets, Brownfield+ helps organizations focus on key business processes while phasing out outdated components. Teams can identify crucial data and processes for the business and use this as an opportunity to improve business insights and agility.

This flexibility helps companies to align implementation speed, risk priorities, and resource availability to their specific needs. Organizations looking to balance agility with stability may find Brownfield+ to be the best choice.

Blue Field (Hybrid) Implementation Approach

As the name implies, a Blue Field implementation approach brings together elements of Greenfield and Brownfield. This offers enterprises even greater flexibility and latitude to implement SAP. Organizations can selectively redesign aspects of their ERP system while maintaining valuable legacy components. This means businesses can optimize specific processes, clean historical data, and transition to S/4HANA at their own pace.

Advantages and Disadvantages of of Blue Field Implementation

Advantages	Disadvantages
One of the primary benefits of the Hybrid approach is risk mitigation. By gradually phasing in new capabilities, disruptions are minimal while the system is being modernized.	Successful execution requires third-party tools and expertise to manage integrations between Greenfield and Brownfield components effectively.

Ideal scenarios

Large companies with complex SAP systems and large data volumes often choose this method for a smooth transition.

SAP Expert’s Perspective on SAP Greenfield vs Brownfield vs Blue Field Implementation

We interviewed, Keri Bowman, Sr. Director of Service Operation at Pathlock, Inc., who has 15+ years of experience in SAP Security design and implementations. We asked Keri to help us understand the differences between Greenfield, Brownfield and Blue Field (hybrid) implementations with practical examples from her past experience, as a SAP security design and implementation practitioner. Here’s Keri’s take on this.

Brownfield Implementation: SAP Expert’s Definition

Keri defines brownfield implementation as follow:

“Brownfield is basically saying pick up our data and move it. We’re not changing any processes. If they’re (implementation teams) going Brownfield, so they’ve already pretty much established, they’re not really changing their business processes at all. So that might be more static, but you still have to create all the roles.”

Impact of Brownfield Implementation on Security & Controls

Regarding the impact of Brownfield Implementation on security and controls, Keri states:

“You still have to install it on the new system. (security tools and configurations must be reinstalled and set up in the new S/4HANA environment.) Same thing for provisioning. You still have to provision it all out. You still have to run certifications. So, it doesn’t really matter which one (brownfield or greenfield) they choose. You have to do it all anyways.”

“The difference? Probably just how fast you can do it, because they won’t be changing. Like if they don’t change their business processes much, it makes the role design go faster and your controls are probably pretty close to what you’re going to have going forward.”

Brownfield Implementation Example: Finance & Treasury Use Case

Keri gives us an example of sap brownfield implementation from her experience as follows:

“Brownfield: I am not changing anything. I am still doing all my finance functionality and my Treasury functionality through SAP. That is not changing. So, the only changes I need to make to roles are where SAP has changed the transaction or the Fiori app that’s being used. So, I may have one or two transactions that swap out there. So, my roles need that slight adjustment.”

Greenfield Implementation: SAP Expert’s Definition

“Greenfield says we might overhaul everything. We might change processes, add them, remove them. If you go with Greenfield or Blue Field, then you’ve got process changes now. You’ve got a three-year project instead of one year to 18 months, right?”

Impact of Greenfield Implementation on Security and Controls

Regarding the impact of Greenfield Implementation on security and controls, Keri states:

“Greenfield: You probably need all new roles. You need all new controls. So it’s going to take longer, but you’re still doing the exact same steps of design, assign, and control.”

“You’re probably also gonna have like significant rule set updates. You’re gonna have significant role design updates. So you’re gonna do all the same steps, but it takes way longer.”

Example of Greenfield Implementation: Finance & Treasury Use Case

“Greenfield could be I’m going to S/4 public cloud, and I’m ripping Treasury out of SAP and it’s going to go sit over in a different system. If I do that, my role design – I no longer need any of the Treasury T-codes. My rule set is one of two things: Either I take out the Treasury risks entirely, or the Treasury risks become cross-app because I have part of something sitting in SAP and part of it sitting in the other system that’s going to run Treasury for me.”

Blue Field Implementation (Hybrid Approach) – SAP Expert’s Definition

“Blue Field is somewhere in between where you’re basically saying: We’re going to move all the data and as much as possible not change processes, but we may take on best practice where we want to.”

“So in that case again, it doesn’t matter. You’re moving to a new system. You have to do all the things we just described. It doesn’t change.”

Impact of Blue Field Implementation on Security & Controls:

“Blue Field: You do fewer process changes and fewer data strategy changes. So, you still have all the same steps, but less time to build your roles, less time to update your rule set, less time to build controls.”

Example of Blue Field Implementation (Finance & Treasury Use Case)

“Blue Field would mean something like: I might choose to keep Treasury in SAP, but I’m going to change the process. Instead of the Treasury module owning so much of the functionality, I’m going to streamline it and really, really narrow it down to almost base functionality. Because maybe I just think that I was running too much stuff through my Treasury department before, and really it should be handled in a different manner.”

“So I’m going to change my business process so that even though Treasury still sits in SAP, it’s much more minimal and the kind of what you would think of as the… best practice.”

Summary from Keri, an SAP Expert on Implementation Choices

Keri summarizes the S/4HANA implementation choices as follows:

Greenfield – overhaul everything. You probably need all new roles; you need all new controls. So, it’s going to take longer.

Brownfield – as much as possible, don’t change any of the processes, don’t change any of the design. So much faster role design, much faster rule set updates, and then much faster control setup if any changes.

Blue Field – you do fewer process changes and fewer data strategy changes. So, you have still all the same steps, but less time to build your roles, less time to update your rule set, less time to build controls.”

Greenfield vs Brownfield Implementations: Decision

Regarding choosing the right approach, Keri states:

“The security work stream is pretty much the same regardless of which one they choose. The only difference might be that they make less changes to their roles. But you still have to create all the roles, still have to do provisioning, still have to run certifications, and still have to implement security controls. The difference is just how fast you can do it.”

Keri highlights an important aspect here regarding the difference between SAP Greenfield vs Brownfield vs Blue Field implementation approaches. She suggests that regardless of the choice of implementation approaches, security workstream will be the same post implementation, that is, implementation and security teams would have to install the new system, provision access to all users, run certifications and implement security controls. The only and core difference between three approaches is how fast you can proceed with implementation.

Hence, right SAP implementation approach is based on evaluating business objectives, technical requirements, and operational constraints. Greenfield allows for total transformation. Brownfield reduces risk and keeps things running smoothly. Blue Field (Hybrid) offers a balanced, step-by-step approach.

Enterprises should match their implementation plans with their long-term digital goals. They can use automation and SAP skills to make the process better. The right approach helps save costs, boosts business agility, and leads to a successful SAP S/4HANA transition.

Frequently Asked Questions