IOW Overview

IOWs define windows of operations for parameters that:

• Have an effect on degradation, when outside certain ranges; and
• Can be influenced by Operations.

Often IOWs are monitored to verify Barrier Statuses. These IOWs should be linked to Operational Control Barriers in the CL and should also form part of a proactive monitoring plan for the asset, to ensure that they are monitored by Operations.

An P- and C-type Barrier (Operational Control Barriers) should be defined as Barriers in the Degradation Management section of the CL and as controlled variable(s) in the Integrity Operating Windows section. The Barrier is the controlled value with its limits for operation. 

The IOWs can be more than the controlled process values. The IOWs should include all variables that should be monitored to ensure the Barrier is effective.

IMS PEI

A Corrosion Loop is normally linked to multiple IOWs. 

A CL is defined as a section of the unit or plant, where the construction materials and process conditions, under which the loop operates, are similar, resulting in the same Degradation Mechanisms to be active in this section of the unit or plant. Additionally, the section should have the same IOWs and it should be one processing step (e.g., cooling/heating, condensation, reaction, etc.)

IMS PLSS

A System is normally linked to multiple IOWs. 

A System is defined as a group of PLSS Equipment, where the construction materials and process conditions, under which the Equipment operates, are similar, resulting in the same Degradation Mechanisms. Additionally, the Equipment should have the same IOWs.