Legacy system modernization in Software Engineering - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a legacy system?

A legacy system is an old computer system or application that is still in use, even though newer technology exists. It often has outdated software or hardware.

beginner

Why do organizations modernize legacy systems?

Organizations modernize legacy systems to improve performance, security, maintainability, and to add new features that old systems cannot support easily.

intermediate

Name three common approaches to legacy system modernization.

1. Rehosting: Moving the system to new hardware or cloud without major changes.<br>2. Refactoring: Changing the internal code to improve it without changing behavior.<br>3. Replacing: Building a new system to replace the old one.

beginner

What is the risk of not modernizing a legacy system?

Risks include security vulnerabilities, high maintenance costs, inability to meet new business needs, and potential system failures.

intermediate

How does cloud computing help in legacy system modernization?

Cloud computing offers flexible resources, scalability, and easier maintenance, allowing legacy systems to run on modern infrastructure without heavy upfront costs.

What does 'rehosting' mean in legacy system modernization?

A Moving the system to new hardware or cloud without changing its code

B Completely rewriting the system from scratch

C Adding new features to the old system

D Removing the system entirely

Rehosting means moving the existing system to a new environment like cloud or new servers without changing its code.

Which of the following is NOT a common reason to modernize a legacy system?

A Improve security

B Make the system harder to use

C Reduce maintenance costs

D Add new features

Modernization aims to make systems easier and better to use, not harder.

What is a major risk of keeping a legacy system without modernization?

A System may fail and be costly to fix

B System becomes more secure over time

C System automatically updates itself

D System becomes faster

Legacy systems can become unstable and expensive to maintain if not modernized.

Refactoring a legacy system means:

A Replacing the system with a new one

B Stopping the use of the system

C Moving the system to the cloud

D Changing the system's internal code to improve it without changing how it works

Refactoring improves the code structure without changing the system's behavior.

How does cloud computing support legacy system modernization?

A By removing all security features

B By making systems slower

C By providing flexible and scalable resources

D By forcing systems to stay on old hardware

Cloud computing offers flexible and scalable resources that help run legacy systems more efficiently.

Explain what legacy system modernization is and why it is important.

Think about old systems and why companies update them.

Describe three common methods used to modernize legacy systems and give a simple example of each.

Consider moving, improving code, or building new.