How to fairly distribute work among users?

Question

Algorithms

In general, the task at first seemed simple to me, but when I began to figure it out on real data sets, it turned out that not everything was so simple (for me).
Condition: there is a certain number (any) of experts (users) who conduct peer review of applications. Two experts are allocated for each application. The peculiarity lies in the fact that Expert_1 performs complex work, while Expert_2 performs simpler work. Applications appear discretely in time (one after another). All information about who how much is stored in the database.
Task: to distribute complex and simple work among experts evenly (fairly).

Note: at any time a new expert may appear without the baggage of completed work. You can not force him to work for everyone in the coming years. :)

Answer 1

make the queue simple, well, or 2 queues - for simple and for complex work. you take from the head of the queue, after the completion of the task you put it at the end.