MEI in PEI

The Maintenance Efficiency Index (MEI) for PEI is calculated based on the RBI Assessment and shown in the RBI Assessment as well as on the linked Schedules.

The MEI calculation

The Maintenance Efficiency Index (MEI) is the ratio of annual risk reduction to annualized cost of performing equipment care tasks.

Where:

POC = Price of Conformance = Inspection, Maintenance & Replacement Costs

PONC = Price of Non-Conformance = S-RBI Consequence of Failure (CoF - Asset)

ETBF = Estimated Time Between Failure = Remaining Life or Design Life

ETBC = Estimated Time Between Consequence = N x RL (default is 5xRL with 100 years being the max). Note: Although the default N value is 5, every site can set their own default via the Application Setting: "MEI ETBC default multiplier". 

Thus, in terms of RBI this becomes:

By default, MEI is only calculated for Category 2 and Category 3 Schedules, and only when linked to RBI Assessments.

Where the MEI can be seen

The MEI value and its inputs are shown in the RBI Assessment, on a separate MEI tab. (For old RBI Assessments you will need to edit the Criticality Assessment before the MEI will update.)

Click MEI to see the MEI tab with input values.The MEI will also show on the linked Schedules (by default only Category 2 and Category 3).

Click the MEI button in the Schedule’s “Scope and plan codes” section to see the MEI input values. 

When you click the MEI button, the MEI inputs are shown. They cannot be edited when linked to an RBI Assessment. The MEI will also be shown as a column in the RBI grid.

Enabling MEI for Category 1 Schedules

Category 1 Schedules are intended to be used for mandatory/code driven and jurisdictional tasks, for this reason MEI is normally not applicable and thus, by default, not calculated. However, it is still possible to be calculated and shown. In this case it must be activated in My Account (see Navigating IMS Main Menu Items).To show and calculate MEI for Category 1 Schedules, you must check the option in My Account. 

When Schedules not linked to RBI Assessment

In PEI the MEI is only calculated for Schedules linked to an RBI Assessment, since the “Asset” Consequence of Failure (CoF) is needed. However, when not linked to an RBI Assessment, users can estimate the inputs to the MEI calculation directly on the Schedule. In thus case it will this be possible to Edit the MEI on the Schedule.For Schedules, not linked to an RBI assessment, an Edit button is available in the MEI section. 

Schedules linked to more than one RBI Assessment

When a Schedule is linked to more than one RBI Assessment, then the lowest MEI will be shown.