A method for control in a process control system, where a graphical user interface of said process control system is arranged with graphic representations of one or more control objects for monitoring and/or control of a process or an equipment. The control system GUI is displayed by a control system client application on a computer or workstation. In addition, one or more applications for monitoring and/or controlling at least one said control object are run in a computing process environment separate from said process control system. No code components execute in the same processing space as that running the GUI for the process control system. Any flaw or error in the extended applications cannot affect the control system program controlling an industrial process in real-time. A control system and a computer program are also disclosed.