Hierarchy is important. Your operators need to move from a general overview down to detailed information in a logical manner.
- Level 1 is a process area overview that covers the operator's entire span of control. Operators should be able to tell at a glance the overall operational condition of the process for which they are responsible.
- Level 2 screens show the sub-unit for which the operator is responsible. There should be a Level 2 screen for each major unit operation, such as a compressor, a reactor, a furnace, etc. These screens should show all the information and controls necessary to perform operator tasks for that unit.
- Level 3 screens show all the detail about a single piece of equipment or process control scheme. These screens are used for diagnostic purposes.
- Level 4 shows details of subsystems, sensors or components and/or miscellaneous information.