In order to select services and add them to the service basket, the user must find the desired service using the search field located above the list of services or by finding it on the list of available services. To put a service in the basket, the user must press the ‘+’ icon, located on the right, opposite the service in question.

                                                      Figure 23. Adding a service to the basket.

There may be various prerequisites when choosing a service, for example, that a certain number of listed services must be selected. These prerequisites and related prerequisite services are displayed in a modal window when selecting the service in the list of services and pressing the ‘+’ icon. The service cannot be added to the basket before the specified prerequisite is met.

The user needs to select the minimum number of prerequisite services, which is specified at the top of the modal window under the name of the main service. The user selects the prerequisite service by pressing the ‘+’ icon. Once the user selects the prerequisite service, a delete icon appears instead of the ‘+’ icon, meaning that the service has been selected for adding to the service basket. By pressing the waste bin icon, the user can remove the selected service and choose another one instead.

As long as the user has not selected the specified minimum number of prerequisite services in the modal window, the window remains open, and transition to the next step is not possible.

                                                     Figure 24. Prerequisite service modal window