Although the number of expected concurrent users is easier to define before a solution is built, the best way to measure workload requirements is by the amount and nature of user activity after the solution is finished.
The majority of users referenced in this document are concurrent users. Although there may be more users of the solution, calculate hardware sizing for the peak number of users that are connected at any given time, plus an additional margin for safety purposes.
Some users are considered research users. A typical research user accesses data infrequently as part of a business process and interacts with a new document every few minutes. However, a continuous user views documents multiple times per minute, such as during indexing. A continuous user can generate more than 10 times the work of a research user, so account for continuous users in your calculations.