Attachment 0053 - Failure Definition - Scoring Criteria.doc

Failure Definition and Scoring Criteria (FDSC) for the High Mobility Multipurpose Wheeled Vehicle (HMMWV)

TRADOC

COMBAT DEVELOPMENTS ENGINEERING

FAILURE DEFINITION AND SCORING CRITERIA (FDSC)

For the

Family of Medium Tactical Vehicles (FMTV)

1 February 2002

Prepared by

Combat Developments Engineering Field Office - Eustis

ATTN: ATCD-ENG-E

Bldg 705 (Wylie Hall) Room 405

Washington Blvd

Fort Eustis, VA 23604-5456

“Excellence in Engineering, Scientific, Technical, & Analytical Services for the Combat Developments Community”

1.0 PURPOSE. This Failure Definition and Scoring Criteria (FDSC) for the Family of Medium Tactical Vehicles (FMTV) serves a dual purpose. The Failure Definition (paragraph 3.0 MISSION ESSENTIAL FUNCTIONS and associated subparagraphs) describes functions that the FMTV variants must provide. Vehicle performance that compromises this functionality has the potential to be considered a failure event. The Scoring Criteria (paragraph 4.0 CLASSIFICATION/CHARGEABILITY GUIDELINES and associated subparagraphs) outline a specific process for categorizing all failure events that occur during system testing. This document is an update of the previously approved FDSC for the FMTV (dated June 1986). Changes made to this document are the inclusion of the Mission Essential Functions (MEF) for the FMTV Load Handling System (LHS) and FMTV-LHS Companion Trailer, and the deletion of the MEFs for the Tanker Variant. These changes are a result of modifications to the FMTV Joint Service Operational Requirements Document (JSOR). This FDSC is applicable for determination of Reliability, Availability and Maintainability (RAM) compliance given the RAM requirements as specified in the requirements document for this program.

CERTIFICATION

01 February 2002

Terry A. DeWitt Date

Eastern Regional Manager

TRADOC Combat Developments Engineering

2.0 INTRODUCTION. This FDSC will be used during scoring conferences to establish an agreed upon RAM database. The database will be used for making reliability and maintainability assessments, which measure RAM characteristics and RAM, related logistics burden for the system for evaluation of Contractor Furnished Equipment (CFE) and Government Furnished Equipment (GFE) against operational criteria. All test incidents, including embedded computer software incidents, will be scored using the guidelines in paragraph 4.0.

3.0 MISSION ESSENTIAL FUNCTIONS. These MEFs apply to both light and medium class vehicles to include the Medium Tactical Vehicle (MTV) Cargo, MTV LHS and companion trailer, MTV Tractor, MTV Dump, MTV Shelters/Vans, MTV Wrecker, MTV Trailer, Light Medium Tactical Vehicle (LMTV) Cargo, LMTV Shelter/Van, and LMTV Trailer. An incident which would result in the inability to safely perform any of these MEFs, to the level described below, will be charged as an Operational Mission Failure (OMF).

3.1 All Variants: Mobility. All FMTV variants must be able to safely begin, continue, and complete assigned missions in all weather conditions and all terrain types as specified in the Operational Mode Summary/Mission Profile (OMS/MP). The capabilities required to complete these missions will not be degraded below those minimums stated in the JSOR.

3.2 MTV/LMTV Cargo Variant (with and without materiel handling equipment). Cargo Handling Function: The MTV/LMTV cargo variants must be able to have cargo safely loaded, secured, and unloaded up to the full rated capacity of the vehicle. Vehicle cranes (when present) must be operable at all times. Inability to safely lift, rotate, lower, or support rated loads will be considered an operational mission failure.

3.3 MTV LHS. The MTV LHS must be capable of performing the following tasks:

a. Self-load/unload Function. The MTV LHS must be capable of loading and unloading flatracks/containers/shelters up to the rated capacity of the system.

b. Trailer Loading/Unloading. The MTV LHS must be capable of loading and unloading the MTV LHS companion trailer with flatracks/containers/shelters up to the rated capacity of the system.

3.4 MTV Tractor. Couple/Decouple Function. The MTV tractor must be able to be coupled to and decoupled from appropriate semi-trailers at all times.

3.5 MTV/LMTV Shelter/Van Variants. No unique mission essential functions exist for the basic shelter or van. The many different shelter and van variants will each have unique requirements due to differing missions. Rather than attempt to define all possible missions now, unique mission essential functions will have to be developed prior to testing of each new type of shelter or van variant.

3.6 MTV Wrecker. The wrecker must be capable of performing the following tasks:

a. Tow Function.

(1) The wrecker must be capable of achieving 35 MPH while towing the heaviest FMTV variant over dry, paved roads of up to two percent grade.

(2) The wrecker must be capable of both flat towing and lift towing all loaded, supported vehicles from the front, and must be capable of both flat towing and lift towing all loaded, supported vehicles from the rear (except the MTV dump truck and extra long wheel base variants).

(3) The wrecker must be able to lift-tow the heaviest FMTV variant up a 22 percent grade secondary road.

b. Winch Function.

(1) The wrecker must be capable of extracting all loaded, supported vehicles when mired to wheel depth. This does not imply that extraction of mired vehicle and a trailer must be accomplished simultaneously.

(2) The wrecker must be able to securely anchor itself in soil conditions of between 60 and 120 RCI. Anchoring may be accomplished by the use of any appropriate combination of vehicle brakes, hydraulic spades, and/or self recover winch.

(3) The wrecker must be capable of extracting itself from mired situations either from the front or rear. Rear self-recovery must be accomplished by the use of the rear winch, and front self-recovery must be accomplished by the use of the self recovery winch.

c. Lift Function.

(1) The wrecker must be able to lift 11,000 pounds and swing this load in an 11-foot radius as measured from the center of the crane pivot point.

(2) The wreck must be able to remove/install supported vehicle power plants and components.

3.7 MTV Dump. Receive/Dump Function. The MTV Dump truck must be capable of receiving a full rated load of materiel under conditions described in the OMS/MP. Also, a fully loaded dump truck must be capable of safely unloading by dumping all bulk materiel. This does not imply that the MTV dump all loads, as dumping may be inappropriate for certain types of cargo or materiel.

3.9 MTV/LMTV/LHS Trailer.

a. The trailer must be able to have cargo safely loaded, secured, and unloaded up to the rated trailer capacity.

b. The trailer must have the capability to be towed at speeds and over terrain conditions consistent with the prime mover operator manual without damage to trailer, load, or prime mover.

4.0 CLASSIFICATION/CHARGEABILITY GUIDELINES.

4.1 Outline. The process of scoring test incidents is divided into two parts. The first part is the classification of the test incident based upon the failure definition. Classification is a categorization of the effect of the incident. The classification is made without regard to who or what caused the incident or when it occurred. The classification procedures are covered in steps 1 though 5 of paragraph 4.3. The second part of the scoring process is the assignment of chargeability for all test incidents. The chargeability step assigns the primary cause for the occurrence of the test incident to one of seven operational elements. Once chargeability has been determined, the appropriate agency will be assigned the responsibility for the corrective action. Chargeability is covered in step 6 of paragraph 4.3.f.

4.2 Generalized Operational Mission Failure Definition. An operational mission failure is any incident or malfunction (actual, intermittent, or incipient) of the system, which caused or could have caused the inability to perform one or more mission essential functions or which presented a critical or catastrophic hazard to personnel or equipment.

4.3 Classification/Chargeability Flow Chart Expansion (shown on page 9).

a. Step 1 - No Test.

(1) Question: Is the incident a “No Test”?

(2) Procedure: If the answer is “No”, proceed directly to step 2. If the answer is “Yes”, score the incident as “No Test” and record the no test category, then stop.

(3) Expansion: The “No Test” category includes the following:

(a) Pretest Checkout. This includes an initial road test and “burn-in” of components. The test plan must specify the number of miles, hours, and etc. for the pretest “burn-in”. Incidents occurring during this period are scored as “No Test”. All incidents detected after the initial inspection period will be scored on their own merits under succeeding steps.

(b) Equipment Modification. This includes all maintenance actions involved in the installation of hardware kits, or incorporation of redesigned components. If the replaced component was not functioning at the time of its replacement with the modification, the incident will be scored on its own merit. The maintenance time will be estimated based on the time to restore the system to its original condition. Subsequent malfunctions of the modification will be scored on their own merit.

(c) Test Peculiar. Malfunctions caused by non-system equipment or people not acting as crew or maintenance personnel are scored as “No Test”. Engineering evaluations to analyze the cause of malfunctions, as well as any malfunctions and/or maintenance efforts caused by the engineering evaluation are scored as “No Test”. This also includes maintenance evaluations conducted as part of the test plan and malfunctions to or caused by test peculiar instrumentation, incidents related to test peculiar diagnostic equipment used in lieu of the diagnostic equipment which will be fielded are scored under their own merit under succeeding steps. Incidents caused by contractor or other maintenance personnel acting as crew or maintenance personnel will be scored under their own merit under succeeding steps.

(d) Daily Checks and Services. This consists of pre-operation, during operation and post-operation checks and services performed by the crew as prescribed by the equipment publication which were completed within 30 minutes using non-excessive quantities of Petroleum, Oils and Lubricants (POL) and on the On Equipment Materiel (OEM) tools and repair parts. If these criteria are not met, the incident will be scored on its own merit under succeeding steps.

(e) Deliberate Abuse. This includes all willful abuse (e.g., performance capability limit test) whether it was prescribed by the test plan or not. Abuse by crew or maintenance personnel will be scored on its own merit under succeeding steps.

(f) Non-RAM Oriented. This step includes those events for which a test incident report might be initiated by the test activity, but which are not incidents used in RAM computations. Examples include suggested improvements, reports of test procedure, unusable or unacceptable replacement parts which were discovered prior to or during installation, inability to meet performance specifications where no malfunction occurred and selected human factors improvements. Recommended changes to the system support package not related to a specific test incident are also covered by this step.

b. Step 2 - Crew Correctable Maintenance Action (CCMA).

(1) Question: Was the incident a malfunction which was corrected by the crew using only authorized on-board tools, repair parts and spares and which was performed within 30 minutes.

(2) Procedure: If the answer is “No”, proceed directly to step 3. If the answer is “Yes”, and before proceeding to step 6, classify as a “CCMA” and record one removal for each spare (i.e., repairable item) used. Record the clock minutes, maintenance man-minutes and repair parts used.

(3) Expansion: This step covers those minor maintenance actions which may interrupt the mission, but which the crew can correct by “immediate action” and continue the mission. These actions include only maintenance specifically authorized at crew level. More than three (3) repeated CCMAs of a given component or subassembly during a 12-hour operational period may result in detrimental mission performance and should be scored on their own merits in succeeding steps. Crew “action” need not be maintenance, but may be simply rerunning the “beginning operations” procedures. In a test environment, there will usually be test peculiar analysis and diagnostic time associated with the action. Delete test peculiar time before scoring this incident. Specifically allowed in this classification is slave starting of a malfunctioning vehicle since there should usually be sufficient vehicles in the vicinity of the malfunctioning vehicle to perform this task. Crew maintenance man-hours are not included in the maintainability parameters. A spare is defined as “those support items that are coded as repairable (i.e., repairable items).” A repair part is defined as “those support items that are coded as not repairable (i.e., consumable items).”

c. Step 3 - Operational Mission Failure (OMF).

(1) Question: Did the incident cause or could it have caused either:

(a) The inability to perform one or more of the mission essential functions to the degree specified in paragraph 3.0?

(b) A critical or catastrophic hazard to personnel or equipment as defined by MIL-STD-882A, 28 June 1977 (reference paragraph 2d of MIL-STD-882A)?

(2) Procedure: If the answer is “No”, proceed directly to step 4. If the answer is “Yes”, and before proceeding to step 6, classify incident as “OMF”, “Essential Maintenance Action” (EMA) and “Unscheduled Maintenance Action” (UMA). Record one removal for each spare used. Record the clock minutes, maintenance man-minutes for both on and off-system maintenance by level and Military Occupational Specialty (MOS) and repair parts used.

(3) Expansion: A malfunction caused by another simultaneous malfunction is scored as one failure. The maintenance time will be the sum of the maintenance time for both incidents. An incipient malfunction whose repair is deferred to a scheduled maintenance period will be scored on its own merit under succeeding steps. If a system has two items which are redundant at all times, an OMF is not scored unless both items are down at the same time. If a backup system is not redundant at all times, a failure of the primary item will be scored as an OMF regardless of the status of the backup system at the time of the incident. System effectiveness parameters must account for the effects of day or night operations, good/bad weather, etc., on the loss of a mission essential function.

d. Step 4 - Essential Maintenance Action (EMA).

(1) Question: Was the incident an unscheduled maintenance action which required corrective action prior to starting the next mission?

(2) Procedures: If the answer is “No”, proceed directly to step 5. If the answer is “Yes”, and before proceeding to step 6, classify as “EMA” and “UMA” and record one removal for each spare used. Record the clock minutes, maintenance man-minutes for both on and off-system maintenance by level and MOS and the repair parts used.

(3) Expansion: Essential maintenance actions include all operational mission failures plus any additional unscheduled maintenance actions, which require corrective action prior to starting the next mission (e.g., repair of a redundant mission essential function component).

e. Step 5 - Unscheduled Maintenance Action (UMA)

(1) Question: Was the incident an unscheduled maintenance action?

(2) Procedure: If the answer is “No” and before proceeding to step 6, classify incident as a “Scheduled Maintenance Action” (SMA). If the answer is “Yes”, classify incident as a “UMA” before proceeding to step 6. For either of these classifications, it is necessary to record one removal for each spare used and record the clock minutes, maintenance man-minutes for both on and off-system maintenance by level and MOS and the repair parts used.

(3) Expansion: Scheduled maintenance actions are programmed services and/or replacements performed at intervals defined by either calendar time or by usage (miles, hours, etc.). Scheduled maintenance also covers those programmed replacements which are dictated by measured wear or deterioration (on-condition maintenance) such as the replacement of tires. These actions must be prescribed by the equipment publications and must have sufficient latitude in their time of performance to permit them to be accomplished during a slack period between missions. Replacement of an item or component prior to its reaching the durability requirement will be charged as an unscheduled maintenance action and will be scored on its own merits.

f. Step 6 - Identification of Chargeable Elements.

(1) Question: What operational element was primarily responsible for the incident?

(2) Procedure: Assign the test incident to one of the following categories.

(a) Chargeable to the Hardware (CH). This includes personnel related incidents that are attributable to characteristics of the hardware design.

(b) Chargeable to Embedded Computer Software (CS). This includes personnel related incidents that are attributable to characteristics of the embedded computer software and Built-In Test Equipment (BITE) and its software. Each occurrence of a recurring embedded software incident will be scored on its own merit.

(c) Chargeable to Crew (CC).

(d) Chargeable to Maintenance Personnel (CMP).

(e) Chargeable to Manuals (CM). This includes personnel related incidents that are attributable to misleading, incorrect or missing information.

(f) Chargeable to Support Equipment (CSE). The support equipment includes special and common tools, spares, repair parts, associated software, etc.

(g) Chargeable to accident (CA). This includes only accidents which cannot be charged to one of the above elements: e.g., an accident caused by a crew error would be charged as “CC”.

(3) Expansion: This step assigns chargeability to all incidents except “No Test.” Actual maintenance need not be performed in order to assign chargeability. During the scoring conference corrective action process, the chargeability may be further broken out if necessary (e.g., Contractor Furnished Equipment (CFE), Government Furnished Equipment (GFE)).

FMTV AMPLIFICATION GUIDE

NO TEST

STEP 1: Is the incident a No-Test?

If yes - Score incident a No-Test and stop. No - Proceed directly to Step 2.

No-test incidents include pretest checkouts, equipment modifications, test peculiar incidents, daily checks and services, incidents related to deliberate abuse, and Non-Ram oriented incidents. Some examples of Step 1 incidents are:

-Initial inspection of the vehicle at the test site.

-Performance tests not related to the Operational Mode Summary/Mission Profile (OMS/MP).

-Equipment or vehicle modification made during the test.

-Final inspection of the vehicle after completion of the test.

CREW CORRECTABLE MAINTENANCE ACTION

STEP 2: Could the crew using the Onboard Equipment and Materiel (OEM), and spare parts have corrected the incident within 30 minutes? If the incident is a tire change the 30-minute time limit is waved. Another condition to the CCMA is that the failure cannot occur more than three times during a 12 hour period and still be a CCMA. Repetitive failures or incidents that occur more than three time will be scored under one of the following steps.

If yes - Score the incident a Crew Correctable Maintenance Action (CCMA), Step 2, and record the pertinent maintenance information, then stop.

No - Proceed to Step 3.

CCMA incidents include those authorized or prescribed crew functions that can be corrected within 30 clock minutes with OEM tools and spare parts incorporated in or carried with the system. If the maintenance time exceeds the specified time limits, the incident must be evaluated at the next step. Tire changes are the only exception to the time limit of 30 minutes. Some examples of Step 2 incidents are:

Tightening of clamps, screws, bolts, etc.

Cleaning off mud

Changing tires.

OPERATIONAL MISSION FAILURES

Step 3: Did the incident cause or could have caused a mission abort? A mission is aborted when mission essential equipment demonstrates the inability to perform at the level of acceptable degradation specified in the JSOR or caused a critical or catastrophic hazard to personnel or equipment as defined by MIL-STD-882B?

If yes - Score the incident EMA, OMF, and Step 3, record the pertinent maintenance information, and proceed to Step 6 to determine chargeability.

No - Proceed directly to Step 4.

Step 3 incidents include any incident that results in the inability to begin or complete a prescribed mission, degrades mission performance below prescribed levels or presents a critical or catastrophic hazard to personnel as defined by MIL-STD-882B. Some examples are:

Class III fluid leaks when the rate of the leak exceeds the fluid reservoir capacity to complete the mission without major damage to the component.

When the vehicle's engine cannot be start even with outside assistance (slave starting).

When an acceptable level of pressure cannot maintained in the tires.

ESSENTIAL MAINTENANCE ACTION

STEP 4: Was the incident an unscheduled maintenance action that can be deferred until the end of the current mission due to the limited effect on a mission essential function and must by repaired prior to the start of the next mission?

If yes - Score the incident UMA, EMA, Step 4, record the pertinent maintenance information, and proceed to Step 6 to determine the chargeability.

No - Proceed directly to Step 5

EMA incidents include actual or incipient malfunctions of the system that need to be corrected before starting the next mission. If an incipient malfunction of an end item was detected during the correction of another malfunction, two separate EMAs will be charged provided that the incidents were unrelated. Some examples are:

Class III engine, transmission oil and coolant leaks.

Air leaks in the service and emergency brakes were no performance degradation in noted.

UNSCHEDULED MAINTENANCE ACTIONS

STEP 5: Was the incident an actual malfunction for which maintenance can be deferred to the next scheduled maintenance and corrected at that level or deferred to end of test?

If yes - Score the incident a UMA, Step 5, record the pertinent maintenance information, and proceed to Step 6 to determine the chargeability.

No - Classify the incident as a "Scheduled Maintenance Action" (SMA) and proceed directly to Step 6.

Step 5 incidents include those that would not cause degradation of system performance. Actual maintenance can be to the next scheduled maintenance and corrected at that level or deferred for the remainder of its specified life before overhaul, replacement, rebuild or salvage as applicable. Some examples are:

Replacement of light bulbs

Loose wire holders

Slightly scuffed wires

Loose bolts

SMA incidents include the periodic prescribed servicing or inspection of equipment accomplished on a calendar, mileage, or hours of operation basis as specified in the maintenance documentation. The maintenance times are chargeable to MR calculations. Some examples of SMA incidents are:

Lubrication

Weekly services

Quarterly PMCS

750 mile services

Semi, or annual services

IDENTIFICATION of CHARGEABLE ELEMENTS

STEP 6: What operational element was primarily responsible for the incident?

Chargeable to HARDWARE (CH)

Chargeable to EMBEDDED COMPUTER SOFTWARE (CS) Chargeable to CREW (CC)

Chargeable to MAINTENANCE PERSONNEL (CMP)

Chargeable to MANUALS (CM)

Chargeable to SUPPORT EQUIPMENT (CSE) Chargeable to ACCIDENT (CA) �EMBED Word.Picture.8���

Manuals

CM

* Record one removal for each spare used.

** Record one durability failure for each component which failed prior to reaching its established durability criteria.

Stop

Support

Equipment

CSE

Accident

CA

Maintenance

Personnel

CMP

Crew

CC

Embedded

Computer

Software

CS

Hardware

CH

Assign Chargeability

Step 6

Step 5

Step 3

Step 4

Step 2

Step 1

No

Yes

Stop

Score “No Test”

Record Category

Score:: CCMA

Record: Removal *

Record:

Clock Mins

Maintenance Man Mins

Repair Parts Used

Score:: OMF/EMA/UMA

Record: Durability **

Record:

Clock Mins

Maintenance Man Mins

MOS

Maintenance Level

Score:: EMA,/UMA

Record:

Clock Mins

Maintenance Man Mins

MOS

Score:: UMA

Record:

Clock Mins

Maintenance Man Mins

MOS

Score:: SMA

Record:

Clock Mins

Maintenance Man Mins

MOS

UMA

EMA

OMF

CCMA

No Test

Incident

1 06/29/16 Distribution A – Unlimited; Distribution Approved for Public Release

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