1. 22 Nov 05 OSD TLCSM Memo Containing PBL Performance Metrics
Operational Availability
Mission Reliability
Logistics Response Time
Total Life Cycle Cost per Unit of Usage
Cost per Unit Usage
Logistics Footprint
On 22 November 2005, the Under Secretary of Defense signed and distributed a Total Life Cycle Systems Management memorandum containing Performance Based Logistics (PBL) performance metrics. Performance metrics were defined in terms of military objectives that will help Project Managers (PMs) to develop and implement PBL strategies that optimize total system availability while minimizing cost and logistics footprint.
The six PBL metrics that may be used to support desired outcomes are Operational Availability (Ao), Mission Reliability, Logistics Response Time, Total Life Cycle Cost typically applied prior to fielding, Cost per Unit Usage typically applied after fielding, and the Logistics Footprint.
The preferred PBL approach is to use long term contracts with incentives tied to a firm period of performance and a PBL acquisition must use at least one of these metrics. The metrics definition used and the sharing of collected data are necessary to measure performance.

2. Operational Availability (Ao)
Memo definition: The percent of time that a weapon system is available to sustain operations
PBL Guidebook concept: Ao is a weapon system or system of systems readiness measurement indicator that explicitly considers the interactions of reliability, availability & maintainability in keeping weapon systems available to perform their missions
PBL Guidebook definition: The percent of time that a weapon system or system of systems is mission capable
Measures the degree to which equipment is in an operable state and can be committed at the start of a mission, when the mission is called for at a random point in time
The Army is presently close to distributing a PBL Metrics Policy and Guide. Both the OSD memorandum and the Army PBL Guidebook contain their own definitions of the PBL metrics. Additionally, some of the Science of Logistics course material definitions will be noted too.
The OSD memorandum definition of Operational Availability (Ao) is the percent of time that a weapon system is available to sustain operations. Note that Ao pertains to the system level of indenture.
The Army PBL Guidebook concept mentions that Ao is a weapon system or system of systems readiness measurement indicator. Ao explicitly considers the interactions of reliability, availability and maintainability in keeping weapon systems available to perform their missions. Logistics support can be optimized using Operational Availability driven RAM models.
The Army PBL Guidebook definition of Ao is the percent of time that a weapon system or system of systems is mission capable.
Ao measures the degree to which equipment is in an operable state and can be committed at the start of a mission, when the mission is called for at a random point in time.

3. Operational Availability Metrics
Ao = Up Time / Total Time = Up Time / (Up Time + Down Time)
In Memo: Ao = MTBM / (MTBM + MDT)
Prior to Fielding for Corrective Hardware (HW) Maintenance Ao:
Ao = MCTBF / (MCTBF + MTR + CWT)
Army has Ao driven Readiness Based Sparing and Level of Repair Analysis models available for use by Govt & Contractors
SESAME optimizes sparing to an Ao input or calculates Ao for the HW corrective maintenance portion if sparing mix is inputted
COMPASS determines the most cost effective maintenance policies to achieve an Ao target
Operational Availability (Ao) metrics are based on Up Time divided by Total Time, which is equal to Up Time divided by the sum of Up Time plus Down Time. In the OSD memorandum, Ao is equal to the Mean Time Between Maintenance (MTBM) divided by the sum of the MTBM plus the Mean Down Time (MDT). Maintenance could include any corrective or preventive maintenance action.
Prior to fielding for determining the corrective hardware maintenance Ao in models, Ao is equal to the Mean Calendar Time Between Failures (MCTBF) divided by the sum of the MCTBF plus the Mean Time to Restore (MTR) plus Customer Wait Time (CWT) per failure.
The Army presently has Operational Availability driven readiness based sparing and Level of Repair Analysis models available for use by both Government and its Contractors. The Selected Essential Stock for Availability Method (SESAME) model will optimize sparing to an Ao input or calculate the Ao for the hardware corrective maintenance portion if the proposed or actual sparing mix is inputted into SESAME. The Computerize Optimization Model for Predicting and Analyzing Support Structures (COMPASS) model will determine the most cost effective maintenance policies for each item in the weapon system to achieve an Ao target tied to the hardware corrective maintenance portion.

4. Operational Availability Metrics
Prior to Fielding for Periodic Maintenance/Actions Portion of Ao:
1 – (Periodic Action Down Time / Calendar Time Between Periodic Actions)
Ao = Corrective HW Maintenance Ao x Product of Ao’s from each type of Periodic Action Causing System Down Time
Modeled with Reliability and Logistics Chain metric inputs to evaluate Ao as a single performance metric. Inputs can be identified & computed in stakeholder segments of responsibility
Note: Use of MTBF in Ao equation is wrong unless a system operates continuously. For unit consistency, all units are in calendar time, while MTBF is in operating time
After Fielding:
Operational Readiness Rate
Full Mission Capability Rate
When considering other factors causing system downtime like preventive maintenance; software updates; pre and post mission servicing; the teardown, movement and setup of a system; or system overhauls, the Operational Availability (Ao) input used in COMPASS or SESAME may be adjusted to a higher value. The Ao adjustment factor from periodic maintenance or periodic actions is 1 minus the quantity of the periodic action down time divided by the calendar time between periodic actions. If an adjustment is needed, the System Ao requirement is now equal to the higher corrective hardware maintenance Ao times the product of Operational Availability adjustments from each different type of periodic action causing system down time.
Ao is modeled with reliability and logistics chain metric inputs. These inputs can be identified and computed in stakeholder segments of responsibility. It is possible to hold a contractor responsible for their input factors that they control impacting Operational Availability if the SESAME model is used to evaluate Ao based on experienced data captured after fielding.
Use to MTBF in an Ao equation is wrong unless a system operates continuously. For unit consistency, all units are in calendar time, while MTBF is in operating time. After fielding, an Operational Readiness Rate or a Full Mission Capability Rate are metrics that may be used to reflect the impact of Operational Availability.

5. Mission Reliability
Memo definition: The measure of a weapon system in meeting mission success objectives. Depending on the weapon system, a mission objective would be a sortie, tour, launch, destination reached, capability, etc.
PBL Guidebook definition: The measure or ability of a system to achieve operational performance for a defined mission or specified mission profile
Probability of performing a mission action without an operational mission failure within a specified mission duration timeframe
The OSD memorandum defines Mission Reliability as the measure of a weapon system in meeting mission success objectives. Depending on the weapon system, a mission objective would be a sortie, tour, launch, destination reached, capability and so on. Note that mission reliability is another system level of indenture metric.
The PBL Guidebook definition of mission reliability is the measure or ability of a system to achieve operational performance for a defined mission or specified mission profile.
Mission reliability is the probability of performing a mission action without an operational mission failure within a specified mission duration timeframe.

6. Mission Reliability Metrics
Discrete Missions:
Number of Successful Missions / Number of Missions Attempted
Sortie Rate for Aircraft
Prior to Fielding:
Mean Time Between Operational Mission Failure
Mean Miles Between Failure causing operating degradation or loss
After Fielding if Operating Metrics Recorded:
Mean Operating Hours Between Operational Mission Failure
Mean Flight Hours Between Operational Mission Failure
Mean Miles Between Operational Mission Failure
After Fielding if Operating Scenarios Not Recorded:
Mean Calendar Time Between Failures causing operating degradation or loss
Mission Reliability for discrete missions is equal to the number of successful missions divided by number of missions attempted. The sortie rate for aircraft closely follows this metric.
Prior to fielding, the Mean Time or Mean Miles Between Operational Mission Failure (MTBOMF) causing operating degradation are useful reliability metrics.
After fielding if operating metrics are recorded, but not each discrete mission, the Mean Operating Hours, Mean Flight Hours or Mean Miles Between Operational Mission Failure may be measured.
After fielding, if operating scenarios are not recorded; the Mean Calendar Time Between Failures causing operating degradation or loss may be measured.

7. Operational Reliability
Mean life units between critical failures
MTBOMF – The average operating hours between the occurrence of an operational mission failure
MTBF - The average operating hours between failures to all critical items in the weapon system that are serially configured
MTBSA – Mean time or mileage between system aborts. (loss or degradation of essential functions causing a system to be unable to start or complete a mission or be withdrawn)
MCTBF – The average calendar time between failures causing down time
Mean Calendar Time(s) between Periodic Downtime Action(s)
The frequency of system failures are sometimes expressed in terms of mean life units between critical failures or incidents causing down time.
The MTBOMF is the average operating hours between the occurrence of an operational mission failure. Mean Time Between Failures (MTBF) is typically the average operating hours between failures to all critical item in the weapon system that are serially configured.
MTBSA is the mean time or mileage between system aborts. An abort is the loss or degradation of essential functions causing a system to be unable to start or complete a mission or be withdrawn.
MCTBF is the average calendar time between failures causing down time.
Mean Calendar Time between periodic downtime actions project the frequency of non-hardware maintenance or periodic system downtime actions.

8. Logistics Response Time
Memo definition: The period of time from logistics demand signal sent to satisfaction of that logistics demand required for weapon system logistics support
PBL Guidebook definition: The period of calendar time from when a failure/malfunction is detected and validated by the maintainer to the time that the failure/malfunction is resolved
Time from when need is identified until provider satisfies that need
All associated supply chain, maintenance time & delivery times of parts
Measures the delivery times of parts to military customers for materiel requisitioned through the DoD logistics systems or other delivery means to a predetermined location
Influenced by support activity order fill rates/stock availability
Influenced by logistics chain times of providers
The OSD memorandum definition of Logistics Response Time is the period of time from a logistics demand signal sent to satisfaction of that logistics demand required for weapon system logistics support.
The Army PBL Guidebook definition is the period of calendar time from when a failure or malfunction is detected and validated by the maintainer to the time that the failure or malfunction is resolved. This time is essentially from when a need is identified until the provider satisfies that need. Logistics Response Time includes all associated supply chain, maintenance time and delivery times of parts. Note that Logistics Response Time can be applied to the system or secondary item levels of equipment indentures.
Logistics Response Time measures the delivery times of parts to military customers for materiel requisitioned through the DoD logistics systems or other delivery means to a predetermined location. Customer Logistics Response Time is influenced by the Support Activity’s order fill rates or stock availability and by the logistics chain times of providers. Therefore, a forward supply support activity’s stock availability of secondary items can also be viewed as a Logistics Response Time PBL metric.

9. Logistics Response Time Metrics
Prior to Fielding:
Mean Time to Restore when Spares Available at Forward Level
Down Time(s) per Periodic Downtime Action(s)
Customer Wait Time per Critical Failure outputted by SESAME
After Fielding:
LRT = Σ(Receipt date – Requisition date) / Total Requisitions
Support Activity’s Stock Availability from Actual Demands
Mean Down Time(s) per Periodic Downtime Action(s)
Order & Ship Time to Customer (for Removal & Replacement)
Repair Cycle Time (for Screening or Repair & Return Actions)
Mean Time to Obtain Back Orders
Potential Improvements to Existing Baseline:
Improved Stock Availability/Order Fill Rate computed from Spares Plus Up based on Support Activity’s Actual Demands
Some Logistic Response Time metrics prior to fielding may be the Mean Time to Restore a system when spares are available at the forward supply support level and the Mean Down Time for each type of periodic downtime action applicable to the system. The Customer Wait Time per critical failure is outputted by SESAME.
After fielding, Logistics Response Time is equal to the sum of the days between the receipt date and the requisition date divided by the Total number of requisitions. A supply support activity’s Stock Availability from actual demands is another possible metric. The Mean Down Time per Periodic Downtime Action may be captured. The Order and Ship Time to Customers for Removal and Replacement supply actions and the Repair Cycle Time for Screening or Repair and Return maintenance actions may be Logistics Response Time metrics. The Mean Time To Obtain Back Orders is another critical Logistics Response Time metric impacting Operational Availability.
After fielding, potential improvements to a supply support activity’s Stock Availability or Order Fill Rate can be optimally computed using SESAME. This may lead to a Plus Up of Spares based on the supply support activity’s actual demand data.

10. Cost Per Unit of Usage
Memo definition: The variable operating costs divided by the appropriate unit of measurement for a given weapon system.
PBL Guidebook concept: The objective is to collect all operating and support costs data and elements at the lowest level required to maintain and sustain a weapon system
PBL Guidebook definition: The total operating and support costs, to include overhead and management costs, for a weapons system usage attributable to a given unit of usage. Usage can be measured in terms of unit density or individual weapon systems; usage factors include miles, rounds, launches, flight hours, time, systems, etc.
Projected Life Cycle Cost (LCC) remaining for fielded systems or their subassembly based on its projected usage rate
The OSD memorandum defines Cost Per Unit of Usage as the variable operating costs divided by the appropriate unit of measurement for a given weapon system.
The Army PBL Guidebook concept mentions that the objective is to collect all operating and support costs data and elements at the lowest level required to maintain and sustain a weapon system.
The PBL guidebook definition of the cost per unit of usage is the total operating and support cost for a weapon system usage attributable to a given unit of usage. It includes overhead and management costs. Usage can be measured in terms of a unit’s density of individual weapon systems. Usage factors include miles, rounds, launches, flight hours, time or systems.
The Cost per unit of usage can also be considered the projected Life Cycle Cost (LCC) remaining for fielded systems or their subassemblies based on its projected usage rate. Note that the Cost per unit of usage typically applies to fielded systems as well as to the subassemblies level of equipment indenture.

11. Cost Per Unit of Usage Metrics
After Fielding if Operating Metrics Recorded:
Total Operating and Support Cost per Mile, Round, Launch, Flight Hour or Operating Hour
Operating costs
Maintenance costs (AMDF price spent on items repaired - repair credits)
Spare & Repair Parts cost (AMDF price from items replenished)
Facilities cost (Military Construction funding)
After Fielding if Operating Metrics Not Recorded:
Total Operating & Support Cost per System Fielded per Year
Annual Operating & Support Cost for Quantity of Systems Impacted
Potential Improvements to Existing Baseline:
Return on Investment* for Improvement vs. Status Quo
* (Discounted Remaining LCC Savings for Quantity Impacted) / Investment Cost
Cost per unit of usage metrics typically applies after fielding. If Operating Metrics are recorded, the total Operating and Support (O&S) cost per mile, round, launch, flight hour or operating hour may be used. O&S costs includes the equipment’s operating costs, its maintenance costs based on the Army Master Data File (AMDF) price with surcharge spent on items repaired minus their repair credits, its spare and repair parts cost based on the AMDF price for the items replenished and facilities cost paid with Military Construction funds if facilities are impacted by the number of systems fielded.
If Operating Metrics are not recorded after fielding, the total operating and support cost per system fielded per year or the annual operating and support cost for the quantity of systems impacted may be used.
Potential equipment improvements to an existing O&S cost baseline applies an Economic Analysis to determine the Return On Investment (ROI) for an improvement compared to the status quo cost. A ROI is equal to the Net Present Value discounted remaining Life Cycle Cost savings for the quantity of equipment impacted divided by the investment cost to accomplish the improvement. Reliability improvement programs for fielded equipment are supposed to have Economic Analyses performed as a Business Case Analysis to help determine which improvements potentially provide the highest Return On Investments.

12. Total Life Cycle Cost Per Unit of Usage
Memo definition: The total operating and life cycle costs divided by the appropriate unit of measurement for a given weapon system.
PBL guidebook lacks definition, but does contain some Life Cycle Cost (LCC) metric factors
Total remaining LCC for weapon systems being acquired prior to fielding. Total non sunk costs remaining over the systems life based on its projected usage rate.
Should be used in Level 2 Business Case Analysis with supportability analysis optimization in the LCC estimate
Useful for new weapon system Baseline Cost Estimate
Besides increasing readiness and reducing the logistics footprint, another objective of PBL is to reduce the Total Life Cycle Cost (LCC) of systems. Product design and supportability decisions made during development prior to fielding determines most of the systems LCC. Therefore, the total LCC was later added as a sixth PBL metric.
The Total LCC per Unit of Usage OSD memorandum definition is the total operating and life cycle costs divided by the appropriate unit of measurement for a given weapon system. The Army PBL guidebook lacks a Total LCC per Unit of Usage definition, but it does contain some Life Cycle Cost metric factors.
This PBL metric should cover the total remaining LCC for weapon systems being acquired prior to fielding. The total non-sunk costs remaining over the systems life is based on its future projected usage rate. This LCC estimate should be used in a Level 2 Business Case Analysis with Operational Availability driven supportability analysis optimization to cost effectively reduce LCC. Since all new weapon system developments require a new weapon system developments require a Baseline Cost Estimate, applying this metric will simultaneously improve the LCC estimate.

13. Total Life Cycle Cost Per Unit of Usage
Prior to Fielding for Acquisitions:
Non-Sunk, Life Cycle Cost Estimate for Acquisition Quantity
Non-Logistics costs remaining associated to systems development, production, test, PM and systems engineering support)
Initial Deployment costs (fielding + NET, simulators & training material + facilities/site activations + mil construction impacted by system quantity)
Recurring Operating costs (operators + energy (batteries & POL) + recurring training + scheduled maintenance + IMMC support + post production PM & systems engineering + PP SW support + HW changes)
Support Costs influenced by RAM (warranty + organic repair + CLS + initial provisioning + inventory holding + replenishments + transportation + support/test equipment + repair documentation)
Disposal cost (equipment demilitarization & disposal)
COMPASS & Time Phased COMPASS in LCET can optimize or analyze RAM related support costs portion
The Total LCC per Unit of Usage typically applies prior to fielding for acquisitions. It encompasses the non-sunk, Life Cycle Cost Estimate for the acquisition quantity.
LCC include Non-Logistics costs remaining for systems development, production, test, PM and systems engineering support. LCC include initial deployment costs for fielding; New Equipment Training, simulators and training material; facilities or site activations and military construction if impacted by the system quantity deployed. LCC include recurring operating costs for operators; energy from batteries and Petroleum, Oil & Lubrication (POL); recurring training; scheduled maintenance; Integrated Material Management Center (IMMC) support; post production project management, systems engineering and software support; and hardware changes. LCC also include support costs influenced by Reliability, Availability and Maintainability (RAM) such as warranties, organic repair, Contractor Logistics Support, initial provisioning, inventory holding, replenishment buys, transportation, support tools and test equipment, and repair documentation. LCC finally includes the disposal cost for equipment demilitarization and disposal. Salvage value is a negative disposal cost.
The COMPASS model can optimize the RAM related support costs portion of the LCC estimate. The Time Phased COMPASS module in the Logistics Cost Estimating Tool (LCET) helps to estimate these RAM related support costs annually from the COMPASS run.

14. Logistics Footprint
Memo definition: The government/contractor size or presence of logistics support required to deploy, sustain, and move a weapon system. Measurable elements include:
Inventory/equipment
Personnel
Facilities
Transportation assets
Real estate
PBL Guidebook definition: Same as memo and includes: measures should quantify the footprint, i.e. weight, area, volume, and personnel, etc. as appropriate
Both the OSD memorandum and the Army PBL guidebook define Logistics Footprint as the government and contractor size or presence of logistics support required to deploy, sustain, and move a weapon system. Measurable elements of the logistics footprint may include inventory/equipment, personnel, facilities, transportation assets, and real estate. The Army PBL Guidebook further mentions in this definition that measures should quantify the logistics footprint, such as weight, area, volume, personnel, and so on as appropriate.

15. Logistics Footprint Metrics
Prior to Fielding :
Total Weight or Transport Dimensions of Deployable Systems, Retail Inventory, Energy and/or Test Equipment
Number of Operators per System
Maintenance Ratio
Energy Requirements (miles per gallon or kilowatts per hour)
Component Commonality (Existing NSNs / Total NSNs)
Deployment to Area of Operations:
Time to Transport Unit’s Personnel & Equipment Impacted
Area and/or Time to Set Up Needed Facilities if Not in Place
Sustainment in Area of Operations:
Total Number of Personnel in the Deployed Area Required to Transport and Sustain the Weapon System
Component Demand Rates & No Evidence of Failure Rates
Logistics Footprint metrics prior to fielding may include the total weight of transportation dimensions of the deployable systems, retail inventory, energy equipment and test equipment. The number of operators per system may be a key metric for platforms. The maintenance ratio influences field level maintainers needs. Energy requirements like miles per gallon or kilowatts per hour influences the size of energy equipment and the system design and the frequency of support to replenish batteries or POL. Component commonality reduces the number of items to manage or order from the field.
For deployment to an area of operations, the time to transport Unit personnel and their equipment is an important metric. The area and/or time to set up needed facilities when not in place may also be considered.
A key metric for sustainment in the area of operations is the total number of personnel in the deployed area required to transport and sustain the weapon system. Also, component demand rates and no evidence of failure rates drives the frequency of ordering item from the field and impacts retail inventory needs.

16. Total Life Cycle System Management
Capabilities
System
Functions
Performance
Priorities
Product
Mission Use
Effectiveness
Reliability
Maintainability
System
Design for Supportability
Effectiveness
Producibility
PBL
Support
Operations/Uses
Effectiveness
Operational
Maintenance Concept
This final diagram pictures how Total Life Cycle Systems Management (TLCSM) influences Operational Effectiveness. It also contains a Performance Base Logistics metrics orientation. TLCSM addresses cost, schedule, performance and supportability. A key to PBL is using at least one of the six high level metrics.
Mission Reliability is a high level PBL metric. Reliability, maintainability, design for supportability and producibility are factors influencing both Product Effectiveness and Support Effectiveness. Maintainability and design for supportability impacts the Logistics Footprint PBL metric. Producibility is separately introduced due to its influence on program schedules and designing the product to reduce LCC.
Operational Availability is a high level PBL metric applicable to support effectiveness. A support efficiency metric like Customer Wait Time impacts the Logistics Response Time PBL metric and support effectiveness.
The LCC for the number of systems impacted is a high level PBL metric. LCC is associated with cost effectiveness when designing the system to reduce LCC and optimize support. Performance based acquisitions use one or more PBL metrics as well as a specifying system performance. If less money is spent to achieve System Effectiveness, more money is available to improve the product, buy more product or improve operations. Therefore, system cost effectiveness ultimately influences Operational Effectiveness.
e.g. Operational Availability
Readiness Rate
Sortie Rate
Support
Effectiveness
Supply Spares Mix
Efficiency
Support Process Times
System Life Cycle Cost:
Design Products to Reduce LCC
Support Effectiveness Optimization