Exam in parts allows one to create one exam with multiple parts with a break between the parts.
The break’s length and the time for scanning answers for each separate time may be set.

First stage - creating the parts 

The floating bar on the left of the editor has a Create part button.
To create parts for an exam, mark the questions of the first part and click Create part.

Attention! All unmarked questions will be automatically added to the second part

After creating the parts, you must set for each part the duration of the part in the exam, the scanning time and the break time
You set a scanning time only if there are open questions that have an answer scanning setting for them.

Second stage - defining the parts

There are two options for setting the transition between the parts of the exam.

1. Fixed times: at a fixed transition point, all students will start all parts of the exam at the same time

2. Unique times: by individual transition, each student will start the parts of the exam according to extra time settings. (students who are configured as having extra time will start the second part later)

To configure the transition between the parts, click the Settings button in the editor and select the desired value

Managing the parts in the exam monitor and on the student side

When an exam is held in parts, relevant details may be viewed on the exam monitor.

See here a detailed explanation on the monitor side and the student side