Legacy Application Migration to the Cloud

08 September, 2020


Companies by the thousands across the world are struggling with the competing interests of on-site legacy applications and the desire to gain more of the cloud advantages for their businesses.

Gartner defines a legacy application as, “an information system that may be based on outdated technologies, but is critical to day-to-day operations.”

On-site, legacy applications have served companies well over the years and the those enterprises are highly dependent upon those applications’ functionality for daily workflow. The other side of the coin, is that these same businesses want to leverage the scalability, cost predictability, elasticity, and reliability of assets within the cloud.

What’s the answer?

Moving those legacy applications to the cloud.

It’s a complex process that requires a team of IT professionals that specialize in moving applications into the cloud, but the benefits are well worth the expense and effort. For the CIO or the Director of Application development, bringing in an outside team to handle that project, frees up you to handle the high-level strategy side of the equation.

In this article, we’re going to talk about how the PRONIX team approaches such a migration.

Our Approach to Modernizing Legacy Applications

A 2018 Flexera report suggests that IT solutions average a five-year lifespan. After that, those assets can become speedbumps in an organization’s effort to make forward progress. Cost reduction, flexibility, collaboration, and dependability can be achieved by moving legacy applications into modern cloud or container infrastructure.

The PRONIX approach to Modernizing Legacy Applications is a security-first strategy. Each step of the migration process is examined to ensure the security and stability of both internal processes and data sets throughout the stages.

IBM has set the standard in this area and has outlined four broad Steps to Modernizing Legacy Applications.

  1. Understand and Prioritize Workloads
  2. Choose New Environment
  3. Select Most Appropriate Tools and Techniques to Modernize the Specific Applications
  4. Successfully Deploy and Manage Modernized Applications

Certainly, each of the above points are only broad brush strokes, but they do provide a starting point for a deeper dive into the migration framework and thought process behind such a task.

A Phased and Layered Approach

When we talk to a CEO about a legacy application migration, the biggest fear that is expressed (after security), is unwanted disruption to workflow. A layered and phased approach to the migration removes this fear and assures the PRONIX client that they can operate as usual while we undertake the complex task of modernizing their legacy applications. A layered approach ensures that only the parts of the application that need to be are rewritten (keeping costs in line), and breaking up the project into phases helps balance the need for uptime and breaks the project into bite-sized pieces.

In June of 2017, Gartner released a very helpful article on the topic of the layered approach. In it, they outlined their suggested process for a Pace-layered Application Strategy. We will summarize that process here.

  • Step 1. Engage the Business
  • Step 2. Define/Review the Business Capability Model
  • Step 3. Segment Business Capabilities
  • Step 4. Create an Application Inventory
  • Step 5. Associate Each Application/Product With the Business Capabilities It Supports
  • Step 6. Assess the Fitness and Value of Applications
  • Step 7. Define/Adapt the Governance Models to Fit Application Strategy Objectives
  • Step 8. Establish Connective Technologies to Deal With the Dynamics Across Layers
  • Step 9. Measure Regularly the Impact of the Strategy

Lift and Shift (rehosting)

Lift and shift (rehosting) is “moving to the cloud” in its simplest form. In this case, the PRONIX team simply “lifts” the application from it’s current on-premise location (usually the company servers) and “shifts” it onto a cloud environment without making any substantial changes to it along the way.

This scenario is most often utilized for applications that are working well with company cloud assets already and are being moved into the cloud as a cost-saving or business continuity measure.


Many times, companies want to move legacy applications into the cloud because they aren’t “playing well” with cloud assets. This is where a cloud specialist proves his/her worth to an organization considering a legacy application migration to the cloud. By taking an application apart and rebuilding aspects of it to optimize it’s effectiveness within a cloud infrastructure, the cloud specialist can provide a seamless interaction between all of a company’s cloud assets. This process results in the removal of siloed information/capability/capacity and allows for workflow automations and efficiencies.


The best succinct definition for refactoring on the web comes from

Cognizant tells us that refactoring is:

“the process of altering an application’s source code without changing its external behavior, in order to improve some of the code’s nonfunctional properties, such as readability, complexity, maintainability and extensibility.”

Let’s look at refactoring in terms of business benefit. By changing some of the code in the legacy application, complexity can be reduced, new functionalities can be introduced more efficiently, and maintenance expenses can be lowered.


Replatforming an application is very similar to the “lift and shift” method that we addressed earlier in our article. The main difference in replatforming is that some of the application is optimized or altered to make the application work better within its new environment.

Is your company considering moving legacy applications into the cloud? Our specialists are ready to answer your questions.

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