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How to Undertake Legacy System Migration?

legacy system migration
Faiza Khalid
CIS engineer | Developer | Tech Writer

Are you interested in legacy system migration for your business software system?

According to a research report on cloud migration, the market for cloud migration services will increase to 7.09 billion US dollars by 2024. Moreover, the data migration market is expected to reach 10.98 billion US dollars by 2025.

The statistics show that the cloud computing industry is on a continuous rise, and it is high time for every business to keep up with technological advancements in order to stay ahead of the competition.

Let’s overview what is a legacy system, and how to undertake legacy system migration successfully.

Legacy Systems

Legacy systems are information technology products that may be built on outdated technologies but are crucial for the day-to-day operations of a business. Legacy systems are common. However, they become a bottleneck to business growth when they:

  • Have an unreasonable maintenance cost;
  • Give poor performance;
  • Need time-consuming updation routines;
  • Provide poor data protection;
  • Violate industry regulations;
  • Offer limited software functionality, etc.

This shows that a legacy system is just not an old piece of software. Any application that is inefficient and needs improvement or replacement is a legacy system.

If a software system starts affecting your business development process or efficient execution of IT operations, it is time for legacy system migration.

Legacy system migration involves moving a software application to a different hardware infrastructure or software platform, preferably based on the latest technologies.

The two main types of legacy system migration are:

  • Lift and Shift Migration – This is done by the IT department of the organization. Such migration of a software system becomes imperative when computer systems engineers recognize a bottleneck in IT operational activities. The legacy system here is not affecting the business development process directly but is rather a technical bottleneck.
  • Business Transformation – This is a response to an inefficient activity due to software that affects the performance and efficiency of the business. For example, business management may decide to shift to a more scalable software architecture instead of a monolithic one due to scalability issues.

Legacy system transformation is conducted in two ways:

  • One-Shot Migration – This involves a transition of a legacy system to a new system in one go at one point in time. The process is well thought out and requires an extensive set of coordinated steps taken by the vendor who is given the task of legacy system migration. 

One-shot migration is often undertaken in industries like Telecom, where a system with a standard set of protocols is transformed into another with a standard set of protocols altogether.

The process requires one-time effort, often comes at a lower cost, but is not always business-friendly and requires more intensive efforts with planning, testing, etc.

  • Parallel Run Migration – This is a gradual transition of functionalities from one system to another. The process consists of multiple phases with continuous cooperation and communication between the involved parties.

The new system and legacy system are operated in parallel. A middleware mechanism is in place to direct relevant requests to both systems. The approach is suitable for migrating large infrastructure or applications with a large audience without much downtime. 

Moreover, parallel run migration is also safer as businesses can retreat without much loss of time and money. The failure risks are also minimized. However, it is more expensive than one-shot legacy system migration, is not very efficient, and may require more effort than the other method.

Next in this article, we will discuss how you can carry out legacy system migration to a cloud infrastructure successfully.

How to Undertake Legacy System Migration?

You will go through the following steps to undertake a legacy system migration:

1. Conduct a SWOT Analysis

As a first step, outline why a system migration is required and if it aligns with the business goals. The objective SWOT analysis should be conducted to analyze the strengths, weaknesses, opportunities, and threats of the migration exercise.

Such an analysis will help you plan effectively multiple aspects and not just the technical process. It will include external dependencies, employee training, compliance factors, security procedures, etc.

The first stage will give you an overview of possible obstacles related to financial, operational, and staff training processes and help you proactively plan and manage them with minimum losses.

2. Assess Your Existing Infrastructure

The next important step is to assess and understand your existing infrastructure and legacy system. This involved going through all the components and related documents to understand their functionality in detail. 

In the case of a black-box system that has hidden functionality, analyze the inputs, outputs, and system responses. For white-box applications with transparent functioning, reverse engineering can be applied to understand system functions and related data effectively.

The assessment of processes, applications, etc. will include network architecture, performance requirements, related infrastructure, availability, etc.

Microsoft Azure, a cloud computing platform by Microsoft, for example, provides a Microsoft Assessment and Planning Toolkit with inventory management and reporting capabilities.

MAP toolkit allows businesses to understand their physical and virtual environments before migrating to Azure. Moreover, it supports maintenance processes for new cloud migrations.

3. Select and Plan Your Migration Strategy

Now, you will select the migration strategy for your legacy system. You can opt for any approach from the following:

  • Lift and Shift: This method copies everything to the cloud. It does not involve a lot of effort to completely migrate a software system as it is. However, it may cause a waste of resources and unnecessary expenses for operations.
  • Application Evolution: This allows businesses to shift their legacy system to the cloud in chunks. The costs, however, remain high for this approach where you identify software components you want on the cloud infrastructure.
  • Application-ReArchitecturing: This method breaks down the software application and rebuilds it in a more advanced and scalable way. It does not mean you are developing a software system from the ground up, instead, you undertake to revamp a codebase introducing more agility and enhancement in the business-related specifications.

Preparing a software application for a cloud can be a daunting process. Cloud service providers facilitate their customers with tools to help them go through the process of application rearchitecting smoothly.

For example, Microsoft Azure provides Azure Service Fabric to prepare a software system for a cloud through microservices.

If you analyze that your software system is performance-intensive, will work better on your current servers, has desktop integrations, etc., you can also adopt a hybrid cloud migration approach.

4. Choose Software Components to be Migrated First

If you plan on migrating your legacy system in components instead of the entire application, you will need to decide which components or functionalities you want to migrate first.

You will map out configurations for migration of the selected software components and also conduct an audit of these components. This will help you refactor your code according to the cloud environment. You will be able to get rid of components that do not serve any business value anymore. 

You will also find out interdependent components. Functionalities that depend on other functionalities and cannot be migrated alone. A mapping analysis will help you migrate such components with minimum disruption to business operations.

5. Prepare Your Cloud Infrastructure

As discussed above, depending on your adopted migration strategy, some applications will just require a lift and shift of software application without much prior work to do. Some will require figuring out components to migrate first, rearchitecting, etc.

For example, moving your corporate documentation to a SaaS service like Microsoft OneDrive will not require much effort. On another hand, you may require license renewals for some external software dependencies to use them on the cloud infrastructure, etc.

6. Evaluate Microservices

There are multiple cloud services available from various cloud service providers. You will need to select services that meet your business needs and align with your business goals. 

Your migration plan, including project scope, requirements, potential issues, etc., will help you go with the appropriate cloud service for your software system. 

For example, depending on your industry, you will have to follow certain regulations and make sure the cloud service you want to employ complies with the industry standards. 

Security is also a major concern when migrating to a cloud since cloud services are third-party services. You have to make sure that cloud services provide you with enough data and system security certifications. You should be able to implement proper security authentication and encryption techniques.

7. Back up

Making a backup of your system is important as it helps to roll back to your previous system in case anything goes wrong with the migration plan.

8. Run and Test Your Pilot Migration

Now, you start with your test or pilot migration of your legacy system. A pilot migration of code will help you test your software system in a test environment that is closer to the actual environment your software application will run.

A pilot migration process will take effort and time as you will do a lot of user testing, performance testing, etc., to prepare your software application code for the actual migration.

You will proactively remove all code bugs that can cause application downtime with actual migration in the real-time environment.

9. Migrate Legacy System Incrementally

Now that you have prepared and tested your system migration plan, you are ready to undertake your legacy system migration successfully. You start by backing up your data so that you do not lose anything during the migration. 

After migration, you will conduct test procedures. You will test security, availability, and compliance.

You will make sure all the existing data is present and users can access everything as required. Moreover, the data quality and data integrity is maintained as a result of successful data migration.

Migrating software applications in increments helps to test code effectively, and resolve any issues that may arise at small levels. 

This is relatively easier than migrating the whole application at once and resolving multiple bigger issues that affect the smooth running of the application and may require an extended downtime to resolve them.

Code bots are also used at this stage to write code in the cloud. After you have run a pilot migration routine, selected the required cloud services, planned increments for system migration, etc., code bots can be employed to transfer code to the cloud faster than humans.

10. Manage Your New Cloud Infrastructure

After the complete migration of the existing systems to the cloud, you will conduct a detailed analysis of the new software system, including the cloud infrastructure. You will make sure the cloud application is running as required at the user’s end. 

This may take several days for you to complete your system analysis and produce a performance report on new systems. In case there arise problems, you can always contact your cloud service provider.

You will also regularly monitor the performance of your application, optimize cloud resources, and analyze the usage of these cloud system resources while tracking alerts and recommendations to improve the cloud resources.

For example, Amazon Web Services for cloud computing provides a cloud monitoring service called CloudWatch. It collects monitoring and operational data as logs, metrics, and events. It allows you complete visibility into your AWS cloud resources, applications, and services running on the AWS cloud or your site.

Final Thoughts on Legacy System Migration

If your software system is hindering your business operations and the overall growth of your business, it is the right time to migrate your legacy system to a more developed and modern IT infrastructure.

Cloud infrastructure is getting popular rapidly given the easy flexibility, scalability, and availability of advanced development, deployment, and hosting services it offers in the form of SaaS, PaaS, and IaaS cloud computing resources.

It is worth mentioning that a legacy system migration is a crucial yet complex task. You have to get it right and with minimum expenses and efforts to ensure successful business continuity and delivery of business services to the user market.

Read our blogs on building cloud integration architecture and get an idea of cloud development.

We would recommend you partner with an experienced team of software developers to undertake this critical process of legacy system migration. These developers should be proficient in cloud computing and should be knowledgeable about the best cloud development and deployment practices, cloud security, data migrations, etc. 

They should be able to help you select the right cloud services depending on your system requirements and should be familiar with the popular cloud services, like Amazon AWS, Microsoft Azure, IBM Cloud, etc. Read our blog here for more details on the top cloud service providers.

If you do not find the required expertise in your IT team, DevTeam.Space can help you via its field-expert software developers community. You can either hire these developers to support your current IT team or outsource your complete legacy system migration project to DevTeam.Space where you can work with qualified software developers and managers migrating your software applications to the cloud. 

All the developers at DevTeam.Space are vetted for their software development expertise and go through an elaborate screening process. You can rest assured that the top talent is migrating your legacy software.

You can easily partner with these software developers for your next software project by sending us your initial project specifications via this quick form. One of our account managers will get in touch with you for your further assistance in getting onboard, planning your cloud migration project, etc.

Frequently Asked Questions on Legacy System Migration

1. What is legacy migration?

A legacy migration involves moving underperforming and outdated software systems or platforms from on-site servers to a modern cloud infrastructure. Migrating legacy systems becomes important when an existing system is causing unnecessary maintenance costs, giving limited functionality, compromising legacy data security, etc.

2. How do I migrate AWS legacy?

You can migrate legacy applications to the AWS cloud using the AWS App2Container service. AWS recommends a three-phase iterative migration process, including stages of Access, Mobilize, and Migrate & Modernize. It also has a comprehensive portfolio of data migration tool libraries that help in the automation and overall simplification of the migration process, like data integration into the modern system, etc. Read more details here.

3. How do I migrate to legacy?

You can migrate a legacy application to a cloud by following a series of steps, including drawing up a legacy system modernization plan, choosing a migration strategy, deciding on the cloud services, running a pilot migration process followed by an incremental migration of the complete system, and finally, monitoring the performance of the new system and managing the cloud infrastructure.

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