We migrated 20 legacy apps written in Delphi 5 to a newer Delphi version

Project type Clients’ pains and concerns Project size Project team size Technologies used in the project

Parking
network

It is getting riskier and more expensive to use our apps that were created decades ago without updating and modernizing them.

During the last year, we lost a couple of non-critical functions. But we are afraid that we will start losing critical functions if we don’t review the source code and don’t update it to the latest Delphi version.

months of work

applications

1 500 000+

lines of code

3rd-party components

Over 20

year-old code

Project manager

3 Delphi developers

QA engineer

Business analyst

Programming languages

Delphi (Object Pascal)

DBMS

MS SQL Server

IDEs

RAD Studio 10.2

Frameworks

VCL

3rd party components

DevExpress, Orpheus, OmniXML, TMS VCL UI Pack

Description

Our client provides parking places across all European countries. They had 20 legacy apps written in Delphi 5. The company contacted us with a request to modernize apps as they had problems with their functionality and their support was getting more and more complicated and expensive.

The programs were already significantly expanded and, consequently, the code required refactoring and reengineering. A part of the code had to be rewritten. That’s why our first task was to analyze the existing code and to get a clear understanding of how everything should function.

Solutions

In order to ensure the best final result, we offered to start the migration process with preliminary business analysis, careful legacy code study, and the creation of a migration roadmap.
The work with each of the 20 applications included migration itself, setting extraction from the source code, code refactoring, and reengineering, as well as migrated app testing.

Migration from Delphi 5 to a newer Delphi version took a little bit more time than we expected. It was related to a more time-consuming testing stage. Every improvement that we introduced (Unicode, 64-bit support) could lead to broken functionality. Our team decided to develop module tests for critical functions. For this aim, we used the DUnit framework.

As a result, all apps were migrated, had all the required functionality, and were ready for work.

Outcome

After the migration, our client has fully functional apps on a modern Delphi version.

Now the client’s IT department can support and maintain their project without any external help.