Make the financial case for modernizing your security stack with this guide to measuring the return on investment (ROI) of your SIEM migration
Legacy SIEM platforms are reaching their limits not just technically, but also economically. Licensing costs are creeping upwards, storage requirements are growing faster than budgets, and security teams are increasingly overloaded with alerts.
On top of that, regulatory and business expectations are rising, with faster incident reporting, deeper visibility, and more precise audit trails required.
With that in mind, modern, cloud-native SIEMs offer a compelling alternative. Microsoft Sentinel, for example, has been shown to deliver a 234% three-year ROI, with payback in under six months, according to a Forrester Total Economic Impact (TEI) study published earlier this year.
But while the technical advantages of a SIEM migration may be clear to CISOs, convincing a CFO or board demands something more concrete: a business case grounded in measurable ROI.
This article provides a practical framework for calculating SIEM migration ROI, which will give you some financial clout to back up an already strong security case.
Not sure whether you need a new SIEM? Read our checklist
Why SIEM Migration ROI Matters
Many SIEM migrations begin with frustration. Security teams are stuck paying for expensive ingestion licenses while having to deal with low signal-to-noise ratios and a flood of irrelevant alerts.
The financial impact of those inefficiencies is often hard to measure, but the economics are hard to ignore:
- This article estimates that Splunk’s list pricing for ingestion ranges from around $1,800 to over $18,000 per year for just 1–10 GB/day, depending on licensing tier and support costs.
- Analyst overload is widespread. Some SOCs face more than 11,000 alerts per day, many of which are never triaged or resolved.
- The average cost of a data breach reached $4.88 million globally in 2024, according to IBM.
- New regulations such as DORA and NIS2 demand faster, more transparent incident response – often with steep penalties for delays.
Turning a blind eye to these considerations can leave your organization exposed to significant financial risk.
By accurately predicting and presenting the potential ROI of the SIEM migration to the board, you will stand a much greater chance of convincing them to invest.
Building a Credible ROI Framework
To convince boards and finance teams, you’ll need to provide clarity. That means moving beyond projections and potential savings.
Below are the key elements to include.
- Time horizon: We would suggest using a 3-5 year view for your SIEM migration ROI model, with cash flows discounted at the organization’s standard cost of capital.
- One-time vs ongoing costs: Separate the migration-specific costs (e.g., tools, consulting, temporary dual licensing) from new running costs (e.g., licensing, staffing, cloud storage).
- Quantified benefits: Use real data from your specific organization to estimate reductions in licensing, infrastructure, analyst workload, and risk exposure. If you are unable to access real data, use credible benchmarks.
- Risk-adjusted scenarios: Offer base, best-case, and worst-case models. This helps CFOs weigh the upside against conservative assumptions.
Remember, the goal isn’t to guarantee a return, it’s to show that the investment has a strong likelihood of delivering one, with the existence of levers to manage risk.
Modeling the ‘Before’ State: The Costs of Legacy SIEM
Start by calculating your current total cost of ownership (TCO), which involves more than just the license.
Licensing & Ingestion
Many traditional SIEM platforms charge based on peak data ingestion, regardless of whether that data is actionable. As mentioned above, a Splunk license, for instance, could cost $18,000 per year for 10 GB/day – before you’ve factored in support and retention costs.
Infrastructure & Storage
On-prem deployments require hardware, SANs, backup media, and power. These costs can account for a significant proportion of a SIEM’s total footprint.
Furthermore, all this hardware requires technical teams to install, maintain, and monitor 24/7 in an emergency. Not only is this costly, but it distracts valuable talent from other technical requirements, which leads neatly to the next point.
People & Productivity
Manual alert triage can consume a lot of your SOC team’s time. With the security skills gap reportedly rising to 4.8m in 2024, this time is more precious than ever and could undoubtedly be better spent in other areas.
Risk Exposure
Even a well-run SOC will miss alerts. A single breach, by IBM’s estimates, can cost nearly $5 million. If cloud-native, automated AI tools reduce that probability by even 10%-15%, the potential risk-adjusted savings are significant.
Click here for a detailed guide to the TCO of legacy SIEMs
Modeling the ‘After’ State: What a Modern SIEM Unlocks
Cloud-native SIEMs introduce a true pay-as-you-go model that easily scales up and down, with options to offload cold data into lower-cost storage tiers. But cost savings are only the start.
Licensing & Infrastructure Savings
The Sentinel TEI study mentioned above reports a 44% reduction in total cost of ownership. These gains come from lower license fees, no on-prem hardware, and reduced support overheads.
Productivity Gains
The same study quoted 93% faster connector deployment, 79% fewer false positives, and 85% reduction in investigation effort. For a typical SOC, that could free up the equivalent of multiple full-time staff members who can be redeployed to higher-value activities.
Risk Reduction
The same study claims that the chance of experiencing a significant breach post-migration is 35% lower. Even if you apply a more conservative 10%-20% figure, the savings in avoided incidents could be substantial.
Elastic Scale
Because modern SIEMs scale automatically, organizations avoid the sudden spikes in capital expenditure caused by new compliance rules or unexpected data growth. This turns what used to be reactive spending into predictable operational expenditure.
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Strategic Benefits You Won’t Find on the Spreadsheet
In addition to what you can see easily, there are many important SIEM migration benefits that are harder to quantify, but still highly worthy of consideration.
Faster M&A Integration
Cloud-native SIEMs enable acquired businesses to connect securely within days, not months. This can significantly accelerate timelines and reduce transitional service agreement costs.
Team Morale & Retention
Reducing alert fatigue has a direct impact on analyst wellbeing. Given high burnout rates in security operations, this can stabilize teams and reduce hiring churn.
Audit & Compliance Readiness
Modern SIEMs often come with pre-configured compliance dashboards for GDPR, HIPAA, PCI-DSS and more. This can shorten audit preparation from weeks to hours.
Environmental Impact
An AWS study found that cloud workloads can be 4.1 times more energy-efficient and reduce carbon emissions by up to 99% compared to on-prem environments.
With sustainability now playing an important part in many RFPs, moving security analytics to the cloud contributes to ESG goals and can provide a competitive advantage in procurement.
Conclusion
Many board members will view SIEM migration as just a technical upgrade, but in reality it is much more than that,
Done right, it reduces costs, improves analyst effectiveness, strengthens your security posture, and pays for itself quickly. Ultimately, it should be viewed as a financial opportunity.
For CISOs and CTOs, the above SIEM migration ROI model can pave the way for transforming operational pain into strategic investment. For CFOs, it offers a clear demonstration of potential value creation.
So, what are you waiting for? Plug your numbers into the above blueprint and arm yourself with a case no-one can argue with.
If you need help understanding the financial benefits of migrating your SIEM to a newer platform, get in touch with our friendly team. We’re vendor agnostic, so our advice is always impartial. Plus, we have more than 100 migrations under our belt, so we know our stuff.
If you’ d like to do some more research, why not download our free whitepaper, The SIEM Migration Buyer’s Guide 2025? It offers a broad range of useful insights for anyone looking to upgrade.
