One of the most common exceptions to best practice is operators in the control center share an operator account. In fact, they do not login or logout out at all. The main reason for this is operators cannot risk losing access to the HMI for even a few second or minutes it takes to login and logout. Additionally, opening all the displays and arranging them could introduce additional delay.

I recently saw a technical solution, a “change shift” feature in a SCADA system. In this system an operator coming on shift would click the change shift button on a display. A login window appears, and the operator enters there username and password. If successful, the login window closes and the HMI resumes operation. All the displays are the same as before. However now all log entries and authorizations are under the new operators username.

If the login fails, the operator can try again. If an emergency situation arises or the operator can’t remember the login, he can click cancel and resume operations without delay.

This is one of many technical solutions. The point is there are solutions to this problem, and we all probably give in to easily to the “it won’t work or is not possible in SCADA” argument.