The 6 Rs of Application Modernization: Choose the Right Path for Every Workload

Executive Overview

Introduction

In our earlier blog, we discussed the importance of building a crucial business rationale before moving your workload to the cloud. Once you have the business objectives, it is time to choose one of the various (6R) app modernization methods. However, you must choose the right path for each workload, as not every workload can follow the same approach because of technical feasibility, application dependencies, and configuration requirements. If you choose the wrong method, you may need to repatriate it and select another cloud migration method. This can result in a squandering of time and money.

Organizations worldwide (85% in a survey) already view cloud spending as one of the top challenges. Hence, it is imperative for enterprises and especially SMBs (Small and Medium Businesses) to tread carefully when selecting the method of cloud migration after deciding the business rationale behind the workload migration.

In this article, we will discuss the 6R’s of application modernization in detail and which method to choose for each workload.

6Rs of Application Modernization in Azure

The 6 Rs strategies of app modernization have been built on the widely popular 5 Rs used to rationalize cloud migration

1. Rehost

It is also known as the Lift-and-Shift method, where you can move your workload without changing the applications. The entire application and its operating environment are shifted to cloud virtual machines with no code modification. It is a cost-efficient way of leveraging the advantages of cloud infrastructure. Common use cases include:

• Mission-critical Applications: that need improved security and scalability. Moving an entire data centre can drastically reduce the cost of ownership by shifting from a CapEx to an OpEx model.
• Analytics Workloads: For these types of workloads, rehosting provides an opportunity to create new capabilities and also integrate new AI features into them. For instance, you can use a PaaS platform such as Azure Fabric or Foundry to unlock enhanced AI services such as prescriptive, predictive, diagnostic and Generative AI analytics.
• Mainframe Interfaces: To support critical operations, it is advisable to retain the stable Mainframe system. However, there is scope to modernise the interfaces and workflows. With this approach, you can mitigate costs and risks while bettering integration across systems and regulatory compliance.

2. Replatform

This approach is also known as the Lift-Tinker-and-Shift method, and the strategy goes beyond rehosting. Like rehosting, it migrates the existing application to a new runtime platform with slight code changes. The Replatform approach delivers incredible results if you’re looking to:

• Migrate a complex application that doesn’t demand any drastic performance improvements.
• Retain existing identity & access management and service frameworks with little disruption
• Accelerate agility, scalability and performance without altering the core architecture

Apart from the use cases mentioned in the Rehosts strategy, which are also applicable here, IoT devices are a suitable use case for Replatforming. Devices in dire need of better integration and scalability could be replatformed leveraging PaaS such as Azure IoT Hub. A fully managed cloud service, Azure IoT Hub acts as a center for secure, reliable two-way communication between millions of physical IoT devices and a cloud application.

3. Refactor

Under this strategy, you can make significant changes to the code structure without any impact on application’s external behaviour. Refactoring is effort-intensive and a visible outcome activity. It suits organisations with strong business preparation and cloud-native capabilities. The initial effort pays rich dividends once your workload is in production, supporting cloud operational scalability. You should Refactor only when you’re looking to:

• Boost scalability, performance and integration of your current monolithic application architecture without a complete design overhaul
• Upgrade compliance, security and governance features
• Enhance the performance of a moderately complex application by initiating code optimization

Common use cases for refactored applications include Enterprise Messaging Systems (EMS) and Monolithic Web Apps. For EMS, Refactoring lets you leverage Azure Service Bus for robust message queuing and Azure Event Hubs for high-throughput event streaming. For Legacy Web Apps, Refactoring lets you disaggregate crucial components without upending the entire app.

4. Rebuild

Building your application from scratch is the right approach if the economics of Replatform or Rearchitect don’t work for you. Rebuilding lets you solve recurring legacy issues and introduce new capabilities to meet emerging business needs. You should explore rebuilding your application when you're looking to decompose a monolithic architecture into microservices and nanoservices using containers and serverless options. Some common use cases for rebuilding are:

• Line-of-Business Applications: Leveraging the incredible capabilities of Azure Cloud, you can replace code-heavy, complicated business applications with low-code, automated, seamless workflows. This approach also helps to create a rapid prototype.
• Frontline Applications: Using Rebuilding, you can do away with obsolete business management and administration tools, enabling you to integrate modern tools for collaboration and accelerating workflow automation. Popular examples of modern tools include Microsoft Copilot Studio, Microsoft Power Platform, and Microsoft Teams. No-code and low-code solutions can also supercharge development and deployment.
• Data Warehousing: If you’re actively looking and exploring data transformation, orchestration solutions, and data archival, rebuilding is the way to go. Microsoft have an efficient data platform known as Azure Fabric that underpins data processing and Machine Learning integrations.
• SQL Server Database: Leveraging the capabilities of Rebuilding, you can use the benefits of PaaS (Platform as a Service) to rebuild databases using Azure SQL Database. Once you adopt PaaS, you can unlock benefits such as automated backups and flexible scaling.

5. Retire

The strategy of retiring involves closing down or decommissioning applications when they are no longer of any use. However, the important data is safely archived for future use and reference.

6. Retain

This approach of application modernisation is employed when your organization is not prepared to modernise the existing applications because of factors such as cost, dependencies and risks.

Comparison between 6R’s of Application Modernization

Key Takeaways: The right application modernization strategy depends on your business case. Go for Retire to mitigate costs, Retain when migration delivers very little value, Rehost for speed, Replatform for calculated gains Refactor/Rearchitect to reap long-term transformation/

Conclusion

Cloud-first strategy can be an effective path to rapid digital transformation. However, before choosing your cloud migration approach, ensure you do it for the right reasons and meaningful business cases. Once you have clarity on the business outcomes, select the right application modernisation strategy to reap the maximum business benefits, whether in cost or speed of service delivery for end customers. There is no right or wrong application modernization path. Evaluate the current state of your workload/applications, assess what business results you’re looking for and then freeze the most valuable strategy.