We discovered that the system might be used by 5 types of users:  clients, doctors, contact centre operator, reception manager, accountant, top-management and shareholders.
All these personas have their own usecases of the system. The whole scope of usecases was realized in sub-systems such as: clients profile, clients documents, doctors tasks management, sample document editor, payment management etc.

We used 12 column grid of Bootstrap. It makes the responsive UI easy to develop.

The system is fully responsive. Clients and doctors would be able to use it on smartphones and tablets. Our UX and UI designers reduced elements on smaller screens for easy mobile usage.

Sprites. CSS

We made life of programmers easier with UI kit that contained full prescription of all elements. Our system analyst wrote all graphics into CSS code for easy front end development.