---
title: "MEI-POC waterfall diagram"
slug: "mei-poc-waterfall-diagram"
description: "How to build the MEI-POC waterfall diagram on the MEC board: export Annual POC and MEI values from Excel, then plot them on a log-log scale."
tags: ["RCM"]
updated: 2026-10-27T23:11:57Z
published: 2026-10-27T23:11:57Z
canonical: "ims-handbook.cenosco.com/mei-poc-waterfall-diagram"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://ims-handbook.cenosco.com/llms.txt
> Use this file to discover all available pages before exploring further.

# MEI-POC waterfall diagram

This article explains how to build the MEI-POC waterfall diagram on the MEC board. The diagram plots the cumulative Annual POC against MEI values on a log-log scale, so you can see where accumulated cost sits relative to MEI and spot a possible cut-off point for an MEI threshold. It follows on from the four overviews described in [MEC board basics](/v414/docs/mec-board-basics).

This MEI-POC diagram shows the cumulative Annual POC against the MEI values.

![Waterfall chart plotting cumulative Annual POC against Mei values on a log-log scale.](https://cdn.document360.io/e492a0e0-a4ba-4aca-8fc6-76b95f91fdf3/Images/Documentation/Waterfall.png?sv=2026-02-06&spr=https&st=2026-11-07T17%3A03%3A45Z&se=2026-11-07T18%3A03%3A45Z&sr=c&sp=r&sig=tuhNca4DVchBbRa6Ww9fQ1vjuKv43rQeGp3s2Yphky8%3D)

The steps below were developed together with TAO Chennai to build the diagram from Excel data.

## Building the diagram

1. Get the FMs with their MEI and Annual POC values.
  1. Export the IMS-RCM analysis grid to get an Excel file with one line per task.
  2. For each task, calculate the annual POC (POC × Ann factor).
  3. Pivot the sum of 'Ann POC' against MEI — see columns 1 and 2 in the image below.
2. Accumulate the Annual POC from the biggest MEI to the smallest MEI (columns 3 and 4).
3. Take −LOG(MEI) and +LOG(Acc POC). For MEI = 0, use MEI = 0.01 to get the LOG: (columns 5 and 6).
4. Make scatter diagram in Excel.

![Data table and charts showing average maintenance costs and related metrics over time.](https://cdn.document360.io/e492a0e0-a4ba-4aca-8fc6-76b95f91fdf3/Images/Documentation/data%20file.png?sv=2026-02-06&spr=https&st=2026-11-07T17%3A03%3A45Z&se=2026-11-07T18%3A03%3A45Z&sr=c&sp=r&sig=tuhNca4DVchBbRa6Ww9fQ1vjuKv43rQeGp3s2Yphky8%3D)

Maintenance Efficiency Index

Price of Conformance

Manage Equipment Care

Failure Mode

Integrity Management System

Reliability Centered Maintenance