You could do the following
Within the OU for engineers set users Account logon times that are consistant with there working hours. Then set a group policy to log users off when their logon hours expire
Under GroupPolicy\Computer Config\Windows settings\Security settings\Local policies\Security Options
Set 'Automatically log off users when logon time expires' to enabled
To get to this right click the Engineers OU>Properties>Group Policy>Click Edit
If you don't have a OU for engineers you could set this at domain level as default logon hours are 24, so this policy won't affect other users.
The more you know, the more you realise there is to know....
CCNA MCP