Legacy system decommissioning vs data archiving: What are the key differences?

Author: Priyasha Purkayastha, Global Content Manager, TJC Group | Co-author: Thierry Julien, CEO, TJC Group

In today’s fast-evolving digital landscape, organisations are under constant pressure to modernise their IT ecosystems, reduce costs, and stay compliant with the ever-changing privacy regulations. Two approaches that frequently come into play when dealing with ageing IT landscapes and large volumes of historical data are data archiving and legacy system decommissioning. Here’s a detailed, step-by-step comparison between both. Read on!

Introduction

With the rapid growth of data across all the industry globally, managing them holistically and efficiently is often a challenge for organisations. Additionally, in this evolving landscape of enterprise technology, organisations face a critical crossroad when dealing with aging IT infrastructure. Let’s be clear, aging IT infrastructures are not only on-premises, but they may also be aging cloud or aging SaaS solutions. As systems reach the end of their lifecycle, navigating strategies to deal with the obsolete systems often becomes a roadblock. What can be done to manage tackle these challenges? Well, for managing data growth, you have data archiving (a good example being SAP data archiving) and for your obsolete systems, there is legacy system decommissioning. The imperative here – you need to understand the difference between these two strategies. Because, prematurely shutting down systems without proper data preservation or maintaining expensive legacy infrastructure far beyond its practical value can prove to be costly. This article provides a comprehensive insight into the definitions, benefits, what sets data archiving apart from system decommissioning, and more.

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Definitions: SAP data archiving vs SAP system decommissioning

Starting off with the definitions of both these strategies, here’s what you need to know –

Data archiving

Defined as a strategic approach that manages data growth, archiving of data can be touted as a secure process that enables long-term data storage and retention, storing critical data (or information) in a secured location, to be used during audits or when deemed necessary.

Additionally, SAP data archiving optimises system performance, ensures the efficient use of database resources within the IT landscape. Moreover, this strategic approach helps organisations maintain a balance between a lean, high-performing IT environment and retaining important historical data.

Also, it is imperative to keep in mind that once the data is archived in the system, it remains accessible to only authorised personnel, while data integrity is maintained to the highest ethical standards.

Legacy system decommissioning

Non-SAP or SAP system decommissioning can be described as a planned, carefully governed, and operationally irreversible retirement of an obsolete system. This can include data stores, middleware, hardware, codes, integrations, and cloud, from all the execution environments and backups. The process helps ensure that the system is no longer reachable operationally; however, it also maintains proper disposal of hardware, licenses, and integrations in accordance with corporate policy, vendor contracts, and environmental or privacy regulations, including secure wipe procedures.

Additionally, the process of legacy system decommissioning eliminates the cost, security exposures, and the burden of technical debts that comes with operating the legacy environment.

However, as per compliance requirements, there are requirements to store data, documents, records, reports and audit trials, which must remain accessible for regulatory, legal, or business purposes. Keep in mind that data privacy still needs to be enforced because so such information may not just be static: you need to replace legacy system with a new topology of applications. This is the trick, for most decommissioning project.

Benefits: SAP system decommissioning vs SAP data archiving

Legacy system decommissioning

The primary advantage of decommissioning lies in the complete elimination of maintenance costs associated with obsolete systems. Organisations can significantly reduce their IT overhead by removing the need for specialised support staff, outdated hardware maintenance, and legacy software licensing.

From a security perspective, SAP system decommissioning eliminates future vulnerabilities inherent in older systems that mostly no longer receive security updates. This reduction in attack surface can substantially improve an organisation’s overall cybersecurity posture. In fact, it’s not an option in current world.

Additionally, decommissioning simplifies the IT landscape, reducing complexity and freeing resources for more strategic initiatives. The elimination of data silos can also improve data governance and facilitate better business intelligence across the organisation.

SAP data archiving

Data archiving helps optimise and improve system performance by reducing the volume of data in production systems. Smaller databases respond faster to queries, improving user experience and system efficiency. This is particularly valuable for organisations planning migrations to memory-intensive platforms like SAP S/4HANA, where database size directly impacts costs.

It will come as a surprise to recent S/4HANA customers, but early adopters know memory don’t come cheap and HANA performance issues are painful and unexpected topics.

Storage and memory cost optimisation represents another significant benefit. Archive storage typically costs substantially less than high-performance production storage, delivering ongoing operational savings. For organisations managing large data volumes, these savings can be considerable. And over time, most organisations end up with large volumes.

When including an efficiently implemented SAP ILM process, compliance management becomes more efficient with proper SAP data archiving strategies. Automated retention policies ensure data is preserved for the required period and can be systematically destroyed when no longer needed, reducing compliance risk and supporting data privacy obligations.

Key differences: Legacy system decommissioning and data archiving

Scope and approach

The fundamental difference lies in scope; simply put, decommissioning addresses entire systems, while archiving focuses on data within existing systems. Decommissioning is a project with a defined endpoint—the complete retirement of a system. Archiving, conversely, is an ongoing operational process that continues throughout a system’s lifecycle. Below are some of the key differences between SAP data archiving and SAP system decommissioning.

Accessing data post-implementation

At times, historical data may be needed for business purposes, like audits and so on. So, having authorised access to that data is important. The key difference with retiring a system and archiving data is that post-implementation, decommissioned systems require alternative access methods, often through specialised applications or reporting tools. Fortunately, TJC Group’s Enterprise Legacy System Application (ELSA) provides a modern interface for accessing legacy data from retired systems.

Archived data, however, remains accessible through existing system interfaces or in a secondary storage. Users can continue to access historical information using, depending on SAP releases and implementation, familiar transactions and reports, maintaining business continuity without requiring additional training or new applications.

However, in both cases, it is crucial to keep in mind that the access to historical data is given to only authorised users. Usually, user access does not change if data is archived or not, as archiving is not a business decision but a cost saving decision.

Cost implications

The cost profiles of these approaches vary considerably. Legacy system decommissioning involves higher upfront costs for data extraction, system retirement, and implementation of alternative access solutions. However, it delivers substantial ongoing savings through eliminated maintenance costs.

On the other hand, data archiving requires lower initial investment. Archiving does reduce the main system maintenance costs (as reduced storage leads to enhanced system performance) and total costs of ownership significantly.

Both Legacy system decommissioning and data archiving may involve ongoing costs for archive storage and management.

Overall, it can be said that the cost-benefit equation depends heavily on system maintenance expenses, compliance and data access patterns.

The risk management perspective

When comparing legacy system decommissioning vs data archiving, risk management is often the decisive factor.

SAP data archiving: While data archiving reduces operational risks such as system slowdowns or storage overuse, it does not eliminate legacy dependencies. Since the system remains active, it’s still exposed. SAP system decommissioning: Decommissioning, however, eliminates the risks tied to legacy systems –

• No need to maintain unsupported infrastructure in some case.
• A modern application for legacy system for remaining cases
• No exposure to security breaches in obsolete systems.
• All critical information is preserved in a secure, compliant, and auditable legacy application, ensuring businesses remain regulatory-ready without retaining outdated systems.

In short, it can be safely touted that data archiving reduces costs while decommissioning removes associated risks.

Legacy system decommissioning vs archiving: When to use each approach

Scenarios favouring decommissioning

SAP system decommissioning becomes the preferred option when systems are technologically obsolete, require expensive maintenance, or pose significant security risks. Organisations planning major system consolidations or facing end-of-support scenarios for critical applications should consider legacy system decommissioning

Regulatory changes that make continued system operation impractical also favour decommissioning. When compliance requirements cannot be met within existing system constraints, retirement may be the most pragmatic solution.

The approach is particularly suitable when data access requirements are minimal and can be satisfied through periodic reporting rather than interactive queries.

Scenarios favouring archiving

SAP data archiving proves most valuable when systems remain operationally viable but suffer from performance issues due to data volume. Organisations with active systems should prioritise archiving over retiring legacy systems

The approach is ideal for SAP environments where users need continued access to historical data through familiar interfaces. Archiving supports business continuity whilst delivering performance improvements and cost savings.

Companies preparing for system migrations, particularly to S/4HANA, benefit significantly from pre-migration archiving. Reducing data volumes before migration can substantially decrease project complexity, duration, and costs.

The strategic relationship between both approaches

Rather than viewing SAP system decommissioning and SAP data archiving as mutually exclusive options, organisations should consider them complementary strategies within a comprehensive data management framework. Many successful implementations combine both approaches to maximise benefits.

Sequential implementation

A common pattern involves implementing data archiving first to optimise system performance and reduce data volumes, followed by selective decommissioning of legacy systems. Obsolete systems that no longer provide sufficient value will be removed, where those with relevant information with be replaced with modern legacy system applications such as TJC Group’s ELSA. This staged approach allows organisations to realise immediate benefits from archiving whilst planning longer-term decommissioning strategies. As a matter of fact, this approach proves to be one of the best for migrating to S/4HANA or any other ERPs.

Hybrid strategies

Some organisations implement hybrid approaches where core systems continue operating with archived data, while legacy systems are decommissioned entirely. This strategy balances the benefits of system simplification with the need to maintain critical functionality. Modern approach also allows storing archived data in some modern legacy decommissioning application.

The choice between approaches often varies by system type, data sensitivity, and business criticality. Business-critical systems warrant continued operation with comprehensive archiving.

Implementation considerations

Data governance and compliance

Both approaches require robust data governance frameworks to ensure regulatory compliance. Organisations must understand their data retention obligations and implement appropriate controls to meet these requirements. Keep in mind that retention is easy; what’s not easy is destruction, what’s tough is selective destruction (AI need data!). Here ELSA by TJC Group comes into play because what’s unique to the solution is selective destruction while keeping tax archive status.

Documentation becomes critical for both strategies. Legacy system decommissioning requires comprehensive records of data extraction and system retirement procedures. SAP data archiving demands clear policies defining retention periods, access controls, and data destruction schedules. We offer both automation and data lineage.

Technical expertise

Successful implementation of either approach requires specialised knowledge. SAP system decommissioning projects need expertise in data extraction, application integrity, system integration (including AI and analytics integration, such as Joule and SAP BDC for SAP related integration). It also requires standard & alternative access solution development. Archiving implementations require deep understanding of system architecture, data relationships, performance optimisation, and deep knowledge of SAP objects and dependencies. Keep in mind SAP ECC archiving and SAP S/4HANA archiving have more differences than similarities.

TJC Group’s 28 years of experience in data volume management demonstrates the importance of working with specialists who understand both the business, technical and regulatory aspects of these potentially complex projects. Our target is to make it simple and secure for you. Our expertise in SAP environments, combined with solutions like the Archiving Sessions Cockpit for automated archiving, the ILM enabled automation version, and ELSA for legacy system decommissioning access, provides organisations with proven approaches to both strategies. ELSA archive synchronisation provides native hybrid models.

Change management

Both approaches impact users and business processes, requiring careful change management. Decommissioning of legacy systems may require training on new access methods and updated procedures. Archiving typically has less user impact (when properly managed) but requires clear communication about data availability and access methods.

The choice between legacy system decommissioning and archiving

The choice between SAP legacy system decommissioning and SAP data archiving depends on your requirement and the position of your system in its lifecycle. A good question will be – do you need one or both, and should you use a (partially) common solution or not; understanding the key differences enables organisations to make informed decisions that balance cost optimisation with operational requirements.

Retiring legacy systems offers the ultimate solution for eliminating maintenance costs and security risks associated with obsolete systems but requires careful planning to ensure continued data accessibility. Data accessibility does not mean same access as before, who will infringe legacy IP, but an adequate display, ideally an adequate generic display.

Data archiving provides a more conservative approach that optimises system performance whilst preserving existing functionality and user experience. It’s about ROI, and accessibility may include transparent data access (depending on SAP product)

As several organisations often employ both strategies as part of a comprehensive data management approach. By understanding when each approach is most appropriate, companies can develop strategies that deliver both immediate operational benefits and long-term strategic value.

Key considerations for decision-making include:

• Assess system viability: Evaluate whether systems remain technically and commercially viable for continued operation.
• Understand data access patterns: Determine how frequently historical data is accessed and by whom. Note that, some strategies allow for skipping this part, reducing costs.
• Review compliance requirements: Ensure chosen approaches meet selected regulatory obligations for data and document retention, destruction, and accessibility.
• Consider implementation complexity: Factor in the technical expertise and resources required for successful execution.
• Plan for the future: Align data management strategies with broader digital transformation initiatives and business objectives.

The final word

Understanding the nuanced differences between legacy system decommissioning and data archiving isn’t just a technical consideration; it’s a route that can determine whether your organisation efficiently transitions to modern systems while preserving critical business intelligence or finds itself locked out of valuable historical data when it’s needed most.

Moreover, understanding this fundamental distinction is imperative as regulatory requirements tighten, data volumes explode, and the true cost of maintaining legacy systems, often consuming 60-80% of IT budgets, forces organisations to make decisive moves. The question isn’t whether to act, but how to act intelligently, on-time, preserving what matters while eliminating what doesn’t.

For organisations navigating these complex decisions, TJC Group’s expertise in legacy system decommissioning, SAP data archiving, and B2G (Business to Government) provides the guidance needed to develop and implement optimal data management strategies that support long-term business success. Contact us for more information!

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