Integrated staging is the process of checking to see if the control
system works as you want. As the system is staged, problems are uncovered in design
philosophy, in documentation, in equipment operation and in many other areas. You can use
the process itself to do this, or you can use a simulation of it. MEL's simulation tools
allow you to see how you process will operate real time in a dynamic environment before
you go to the field. Once there, you'll know with confidence that any problems that
surface are related to the equipment in the facility ( i.e. cables) and not with the
control scheme.
MEL's simulation models are typically built from completed PFD’s, P&ID's and
device specifications and other documents. The same equipment names, numbers, and P&ID
numbers are used for identification to make it easy to go back and forth from model to
documentation.
The initial model is built using simulated controls (from the MEL controls library) to
tune and verify the model operation against specifications. Once the model operation is
validated they will be replaced with control system communication objects. These will be
tagged based on the plant tagging convention, and cross references are automatically
provided. This cross-reference tag list will then be used to fill in the tagged
communication objects with the specific control system I/O dialog items. This allows the
simulation to be built before the control system configuration has been completed, thus
allowing testing to begin as soon as configuration is done.
The documentation to be
verified is the I/O list, the P&ID's, control system graphics, and logic diagrams. The
control system configuration and operation is checked against each of these documents. As
each point and control loop is verified it is checked off in the control system
documentation. Configuration problems are corrected as checkout progresses and the
documentation/design is changed as needed.
By using MEL’s dynamic simulator for staging the problems are found in the test area,
not in the field on the process itself. This saves time, money and is less dangerous and
potentially harmful than testing on a live system.
