We helped a healthcare equipment manufacturer to modernize software system built with Delphi 20 years ago

As it was mentioned above, a software complex has a huge amount of different mathematical and scientific calculations, formulas and so forth. UI is only a part of the whole complex, around 25% of all migration work. This is why it was so important to prepare existing software for migration by covering all mathematical and scientific parts with unit tests. Nobody can give a guarantee that after “as is” migration from Delphi 5 to Delphi 10.2 everything will work correctly. “As is” migration is only the first step of migration, because we also had a plan to use Unicode for the strings, add 64-bit support, and add multi-threaded calculations. Each improvement from thу mentioned before can bring to us a lot of risks of broken functionality. This is why we made a decision to develop as many unit tests as possible for the existing Delphi 5 projects.

We extracted almost ~1500 test cases. Here we also had some difficulties, because we cannot find actual input parameters and get correct expected results, because even the client didn’t have such information. Some knowledge was lost, some features were not documented well and some of them we could get only with connected equipment.

The second main challenge was about component migration. Software complex had it’s own BI engine, based on TChart components and had almost nothing coming with the initial version of TChart. Of course we couldn’t migrate BI engine “as is” – TChart components in Delphi 10.2 are not compatible with Delphi 5 version. Finally we made a decision to extract BI to a separate branch, remove any connections to TChart and migrate it to Delphi 10.2 as a separate product.

Migration was split to multiple steps:

Prepare unit tests

Components migration

Different components have different migration roadmaps – some of them were replaced, some of them where migrated “as is”, some of them were updated to up-to-date versions with adding support for the differences (imagine how differently components can be for Delphi 5 and Delphi 10.2 – yes, that’s totally different worlds, but we still can have good possibilities for source code compatibility);

Mathematical modules migration

Some of them are DLLs and that’s the best opportunity for faster migration;

UI/UX migration

Writing test cases

We wrote automation tests scenarios using Selenuim testing tool;

QA/Testing

Testing with equipment (client’s side);

Re-engineering and improvements

As it was mentioned before, client asked us to add an Unicode support, implement multi-threading for some slow calculations;

Deployment to existing customers

Our client operates a lot of devices and equipment using the software. Of course it was impossible to provide for our team all these devices, especially the cost of some of them are hundred thousands US dollars. This is why we organized the QA process with equipment together with the client’s QA team.