Maintenance Cost Estimate (MCE) User Guide

1. Nomenclature

Term	Definition
ELF	Environmental Loading Factor
LOI	Level of Indenture
LRU	Line Replaceable Unit
MADE	Maintenance Aware Design Ecosystem
MCE	Maintenance Cost Estimates
MPD	Mission Profile Definition
MTTF	Mean Time to Failure
MTTR	Mean Time to Repair
RAM	Reliability, Availability & Maintainability
RCM	Reliability-Centered Maintenance

2. Introduction

The Maintenance Cost Estimates (MCE) analysis is used to generate and compare the costs of maintenance procedures for an item or groups of items in a system, across its lifetime of operation. A lifetime is defined by aggregated mission profiles assigned within the Mission Profile Definition (MPD) tool. The MCE analysis is an estimator and hence does not contain procedural steps or decision logic, unlike the RCM analysis. Furthermore, it is not intended to be used as a rigorous maintenance analysis tool.

MCE will likely be applied when the user is seeking to estimate the economic cost of supportability of a design.

The main metrics used for comparisons are Total Cost and Cost Per Hour. These cost metrics collectively provide an overview of both scheduled and unscheduled maintenance costs, which are tallied in the overall sustainment costs of a modelled system.

MCE analyses can be applied to any level of indenture in a MADE model. Depending on the level of analysis required, the MCE analysis can be applied as a general maintenance cost estimate at a subsystem level or a more specific cost estimate for lower-level items.

It is recommended to apply the MCE at the lowest level, such as the LRU (Line Replaceable Unit), depending on the level of design maturity and knowledge base of the system in development.

3. Comparison between MCE & RCM Analyses

Table 1: Comparison between MCE & RCM Analyses

Maintenance Cost Estimation (MCE)	Reliability-Centered Maintenance (RCM)
Basic comparison of costs for a system that is still in the design or development stages.	RCM is a broad analysis method used to assign maintenance actions and procedures to a developed product.
Does not include the following considerations: Safety; Operational; Specific Failure Modes.	Takes safety, operational, and economic impacts of failure into account.
Applied at an earlier stage during system development.	Applied during the in-service life of a product.

4. MCE Workflow

(Figure 1: MCE Workflow — a diagram/image with no additional extractable text beyond its caption. It shows the overall process flow of the MCE analysis, elaborated step-by-step in the Worked Example chapter.)