PEI Hierarchy - Overview

The IMS Hierarchy is set up to implement the Degradation Management work process. In general, IMS PEI is about identifying when and what Equipment to inspect and to have an audit trail of the results of these inspections. In IMS, the “when” is defined in an Equipment Inspection Schedule event. The results of the inspection are captured in the Equipment Condition History (ECH). The user checks which Schedules are due (having a Scheduled date close to Today), then performs the inspection, captures the inspection results and credit the Schedule(s) in the ECH. In case of recurring Schedule(s), a new Schedule will automatically be created with a new due date.

The figures below show the important objects and illustrates how the flow between the different objects occur.

IMS PEI Hierarchy 

IMS PEI Workflow. The objects that are interfaced (Equipment, Schedule, ECH) with a CMMS are indicated with an interface symbol.

Locations

Locations are organized in Site – Plant – Unit – Functional Location (FLOC). These are the highest hierarchy levels in IMS. The FLOC typically have specific operating parameters: flow rates, temperatures, pressures, fluid composition. FLOC IDs never change, at least until the Unit or the FLOC is retired. 

Generally, each FLOC has one child, which is a piece of Equipment (with an Equipment ID). Some FLOCs cover more than one Equipment group, e.g. For Exchangers-FLOCs two separate pieces of Equipment can be assigned: a Bundle and an Exchanger. The Equipment in turn might contain Circuits and/or Components. Some data will or can be inherited from a higher level (e.g. Inspection Reason is inherited from the FLOC down to Equipment and Circuits). 

When you click the Hierarchy button, the Hierarchy side panel opens and shows a tree view of the full Site (from the Site to the level of corrosion Circuits and Components). See Other IMS Main Menu Options.

The Hierarchy side panel.

Site, Plant, Unit (Toplevel)

Details for Sites, Plants and Units are registered and organized in Settings\Company\Toplevel. See Configuring the Toplevel via Settings. 

FLOCs

The Functional Locations (FLOCs) are registered in the FLOC Main Screen. See PEI - Functional Locations (FLOCs).

Equipment

An Equipment object represents a physical pieces of Equipment, which can be measured, having specific materials, coatings, dimensions, weld joints, etc. An Equipment is designated to a FLOC and contains both Circuits and/or Components. An Equipment ID is valid until the Equipment is replaced. When replaced, a new Equipment ID will be assigned. For sites using the GSAP interface, the FLOCs and Equipment cannot be entered directly to IMS. The hierarchy information for these sites is determined by GSAP.

Various types of Schedules can be registered for an Equipment and are shown in the Schedules section. Default Schedules are automatically created when a new piece of Equipment is added and act as a “safety net” for which the minimal time interval should be set (12 months).

For more information see PEI - Equipment.

Schedules

Schedules can be assigned to both Equipment and Circuits. On Equipment level, there are Inspection, CAIR or RBI Re-assessment Schedules, while for Circuits only Corrosion Schedules are assigned. All inspection Schedules can be credited by adding and approving ECHs, which includes detailed information about the inspection performed. The Corrosion Schedules are credited by calculating and Approving the Calc Summary. 

For more information see PEI Schedules and Step 13 Barrier Verification - Execute, Analyze, Document.

Condition Histories (ECHs)

Equipment Condition Histories (ECHs) are registered for a piece of Equipment and capture the inspection findings, using Checklists and a narrative. Approving the ECH will credit possible Inspection Schedules and create new Schedules for the Equipment when the credited Schedule is recurring. The user can fill out Checklists that will show the inspection condition and repairs performed, depending on the Schedules scope or Inspection Strategy (IS) (i.e. looking for certain Degradation Mechanism).

For more information see PEI Condition History (ECH).

Circuits

A Circuit covers all Piping- or Equipment-Components where the same Corrosion Rate (CR) is Expected/Measured. This is the level on which Wall Thickness (WT) measurements are inputted, and CR calculations take place: 

These wall thickness measurements are captured per CML/MP, which are the lowest level of the hierarchy. A Measurement Point (MP) is an area on a location on the Equipment. These locations are called Condition Monitoring Locations (CML). Each CML can have multiple MPs and each Equipment can have multiple CMLs. CML’s are grouped in corrosion Circuits with the same expected Corrosion Rate (CR). 

There is a special Schedule type, called Corrosion Schedules. As an exception this is defined directly on the corrosion Circuit and not on the Equipment. This Schedule type simply defines when the CMLs of the corrosion Circuit need to be measured. The Circuit also has a Measurement Set (MS) section. The MS specifies which CMLs to inspect. 

For more information see PEI Circuits.

Components

Components are created in IMS in order to perform the RBI risk analysis on Equipment. A piece of Equipment can have one or more Components. Examples of Components would include the top of a column, the water boot of a separator, the Shell of an Exchanger, and the Tubes of an air cooler. When a new Component is created/added it should always be designated to an Equipment. Once a new Component is being created, it should also be assigned to a Corrosion Loop that shares the same operating conditions.

Components are the separate parts of an Equipment that have the Barriers against the Threats of the Degradation Mechanisms (DMs). Thus, they need verification through inspection. The RBI risk analysis therefore takes place on this level, i.e. each Component – DM combination is assessed. This helps to determine the Next Inspection Date (NID). The figure below shows where the RBI Criticality and Confidence comes in.  

A more detailed hierarchy flow. This shows how the RBI Criticality and Confidence help to determine the Next Inspection Date (NID).

 An RBI Analysis can be created or accessed from the Component details screen. See Step 3 Start RBI Analysis and Assign DMs to the Component.

Important

• A Component must first be linked to a CL before applicable DMs (defined for the CL) can be assigned to the Component.
• Components and Circuits can be set to be inherit. This way the Component can inherit the Corrosion Rate information (SCR and RCA) from the Circuit. 

See Relationship between CLs, Components and Circuits. 

Corrosion Loops

Corrosion Loops (CLs) are groups of Components where Degradation is Managed in the same way. On this level Degradation Mechanisms (DMs), Barriers, and Integrity Operating Windows (IOWs) are defined. In this way the CL supports the Corrosion Management Framework (CMF). 

In terms of Hierarchy a CL is assigned to a Plant or Unit, since it includes the DMs expected to be affecting that location. These DMs are subject to circumstances (i.e. IOWs such as temperature, pressure, fluids) in or around the Equipment. The Equipment is broken down in parts (i.e. Components) and will be assigned to CLs that share the same process conditions. In other words: the circumstances of a CL and applied DMs can be assigned to multiple Components. 

The below figure helps to explain the relationship between CLs, Circuits, CMLs, and MPs:

The relationship between CLs – Circuits – CMLs and MPs are illustrated.

For more information see PEI CL - Overview as well as Corrosion Loops (CLs) - Theory.