Carl Byington with PHM Design, LLC reviews: Conceptual functional architecture: Describes functions and functional interactions Traces functions to capabilities or services desired in the COO Conceptual physical architecture: Allocates and describes the conceptual implementation of functions Traces implementation to function Activity Flows: Identifies primary paths through the principal use-cases to meet the goals and interests of the stakeholders Trades identify preferred path which, in turn, provides context for requirements derivation and operational thread development. #phmdesign https://phmdesign.com

2. • A little bit about how PHM Requirements
are manifested
– aka - Who moved my cheese?¥
• The impacts on operational, maintenance,
and logistics measures of effectiveness
• Implementation tradeoff strategies
• The cost assessment for the PHM and
the benefits
• Some examples of cost analysis and
motivations that might help your current
initiatives
¥Who Moved My Cheese? An Amazing Way to Deal with Change in Your Work and in Your
Life, by Spencer Johnson, Putnam Publishing, 1998.

3. • Reliability
– Was: Component MTBF is king.
– Is (becoming): MTBF yes, but prevent system aborts (MTBSA) and
No Surprises! What’s my updated failure risk based on usage?
• Operational
– Was: Performance is king. Scheduled maintenance is acceptable and
doesn’t count against operational availability. Limited to no predictive
diagnostics in field.
– Is (becoming): Balance of performance, availability, and affordability.
Embedded PHM capability. “True” operational availability by reducing
as many maintenance actions as practicable. Faster deployment
readiness/optempo. Mission readiness assessment and decision
aiding with better predictive information.
• Maintenance
– Was: Preventative maintenance is acceptable and doesn’t count
against availability. Three level maintenance systems. “Silo” approach
to information management and diagnostic/repair process.
– Is (becoming): Condition Based (and JIT) Maintenance. Preference
for 2-Level maintenance. Merging of intermediate functions between
operational and depot levels.
• Logistics, Supplies, and Sparing
– Was: End user’s problem and significant spares market for suppliers
– Is (becoming): Performance-Based Logistics (PBL) and Full-service
contractors risk. Autonomic logistics support concept of operations.

4. Corrective Preventive CBM Proactive
§ Small Items
§ Non-critical
§ Unlikely to fail
§ Redundant
§ Predictable
Wear
§ Consumables
§ Known Failure
Patterns
§ ‘Random’
Failures
§ Minimal Wear
§ Critical Items
§ PM Induced
§ Inspection and
MMH drivers
§ Accurate Usage
Prognostics
§ Incipient Fault
Detection/Diagnos
is
§ Health & Adaptive
Prognostics
Evolving Maintenance Approach
Condition-Based
Corrective
Preventive
Percentage of Maintenance Actions
100%
Present Future
Eliminated
CBM+ Implementations

5. US Navy: OPNAVINST 4790.16, Condition-Based Maintenance
(CBM) Policy, 6 May 98
– “CBM Methodology shall be used to determine maintenance
decisions and reduce scheduled maintenance and manpower
requirements …”
– “Chief of Naval Operations (CNO) will fund naval programs,
processes, and enabling technologies proven applicable and
effective in supporting the maintenance, manning, and cost reduction
objectives of this instruction.”
US Army VCoS Memo: Accelerated Application of Embedded Diagnostics, 30 Apr
98
§ “… include embedded diagnostics on all new and retrofit equipment…”
§ “...We will not field systems or retrofit equipment without embedded diagnostics. If
a tradeoff must be made because of funding, Army policy will be to obtain fewer,
more capable systems.”
Hint: Google “CBM+ requirements” for a newer mandate list

6. • Apply embedded diagnostics to detect XX% of failures relating to
essential / mission critical functions
• Improve availability – readiness & downtime.
• Maximize combat power w/reduction in logistics & personnel
w/reduced demand for maintenance & supply
• Enable an anticipatory maintenance (JIT, pit-stop,etc.)
maintenance
• Provide User/Soldier/Sailor/Marine notification of pending failures
• Provide vehicle monitoring of conditions and mission
capability/readiness status
• Embedded diagnostics & prognostics for individual components,
LRU’s & LRM’s; meet levels of detection or isolation to meet
maintainability goals.
• Enable vehicle-to-vehicle prognostics and mission decision aiding
• Minimize the need for test and ground support equipment
• Embed instrumentation, provide at-vehicle test and diagnostics

7. LRC/Module On-board On-Ground
F u n c t i o n a l
Failures
96% Detection Capability
Non-Electronic 80% Isolation 85% Isolation, 3 LRCs or
less
75% Isolation, 1 LRC
Electronic 85% Isolation, 1 LRC

8. PHM System Requirements Summary
Coverage: Detect up to 40 Faults (on monitored systems)
Failure Detection/Diagnostics: Detect and Isolate > 75% of failures
(< 5% false identification)
Failure Prognostics: Prediction with > 90% Confidence (threshold) and
>96% Confidence (objective) at least one (threshold) and seven
(objective) 24-hour missions

10. Logistics
CBM+ Engineering
Maintenance
Command
Operations

11. § Example: Telelogic’s
Rhapsody
§ Models constructed
using Systems
Modeling Language
(SysML™)
§ Other PHM Design
and Metrics tools to
capture underlying
requirements

12. Systems
Engineering
Repository
System
Acceptance
System
ITV&V
Module
ITV&V
Implementation and Unit Test
Physical
Architecture
Logical
Architecture
Functional
Architecture
System
Assessment
System
Baseline

13. § Conceptual functional architecture
§ Describes functions and functional interactions
§ Traces functions to capabilities or services desired in the COO
§ Conceptual physical architecture
§ Allocates and describes the conceptual implementation of functions
§ Traces implementation to function
§ Activity Flows
§ Identifies primary paths through the principal use-cases to meet the
goals and interests of the stakeholders
§ Trades identify preferred path which, in turn, provides context for
requirements derivation and operational thread development.

14. 3rd Party Database Server
User
Windows Application
Browser (Web application)
Ground Station Server
Web Service
• Authenticate user
• Get recent files
• Perform analysis
• …
Database
Security:
128-bit encryption
Internet
• IVHM Server shall be web-accessible
• 3rd Party Databases accessed through network

15. • Rhapsody utilized to design system:
– Components – Coherent / decoupled
– Information flow – What travels between pieces
• Functionality and information flow is being defined
• High-level design enables partitioning / testing
Platform
«block
»
Attributes
Operations
Groundstation
Groundstation Groundstation
«block
»
Attributes
Operations
ExternalService
Platform
«flow »
PlatformUpdates
ExternalService
Platform
ThirdPartyService
«block
»
Attributes
Operations
ServiceUser
«flow »
ServiceData
ServiceUser
EnterpriseAccess
«block»
itsDataAccessLayer:DataAccessLayer
1
PresentationData
Logic
Report
Query
itsPresentationLayer:PresentationLayer
1
Display
Command
itsLogicLayer:LogicLayer
1
DisplayData
CommandData
PresentationData
«flow»
DataAccess
«flow»
itsDataServiceLayer:dataServiceLayer
1
Display
«flow»
Command
«flow»
DisplayData
«flow»
CommandData
«flow»
itsDataStorageLayer:DataStorageLayer
1
Report
«flow»
Query
«flow»
DataIn
itsSoftwareUpdateEngine
1
ConfigCheck
ExtResponse
«flow»
DepSysUpdate
PlatformUpdate
ExtCommand
«flow»
DeployData
«flow» PresentationData
Logic
Report
Query
Display
Command
DisplayData
CommandData
PresentationData
DataAccess
Display
Command
DisplayData
CommandData
Report
Query
DataIn
ConfigCheck
ExtResponse
DepSysUpdate
PlatformUpdate
ExtCommand
DeployData
Break into:
SoftwareUpdate Engine
MissionDataEngine
SecurityEngine
Each has these layers scoped to their
function.
Groundstation
«block»
itsWideAccess:EnterpriseAccess
1
ConfigCheck
ExtResponse
DepSysUpdate
PlatformUpdate
ExtCommand
DeployData
itsDeployedSys:DeployedSystem
1
ConfigCheck
«flow»
ExtResponse
«flow»
ExtCommand
«flow»
Update
«flow»
DeploySysUpdates
PlatformUpdate
«flow»
PlatformUpdateInstructions
Enterprise
«flow»
PlatformData
Platform
ExternalService
«flow»
«flow»
Platform
«flow»
PlatformUpdates
ConfigCheck
ExtResponse
DepSysUpdate
PlatformUpdate
ExtCommand
DeployData
ConfigCheck
ExtResponse
ExtCommand
Update
PlatformUpdate
Enterprise
Platform
ExternalService
Platform
Requires Authentication
When the DeployedSystem User connects to the
Enterprise System through the EnterpriseServices link,
the remaining interfaces between deployed and
enterprise automatically establish themselves.
Link to Existing
Ground Station
Software
Link to
Enterprise
Application Layers

16. • Engineering design tool used to:
– Prioritize spoken and unspoken customer
wows, wants, and needs
– Translate these needs into technical
characteristics and specifications
– Build and deliver a quality product or service
by focusing everybody toward customer
satisfaction
• Useful in the current setting to
understand “how” to implement and the
interdependencies
http://www.qfdi.org/

17. Strong
Medium
Weak
Technical Requirement
Prioritization
(Assumes Sortie-type Aircraft)
1. Onboard Data Storage
2. Real-Time Data Collection
3. Open System Design
4. Open Data Transport Protocols
5. Real-time Signal Processing
6. Real-time Signal Monitoring
7. Onboard Reasoning
8. At Wing Processing
9. Use Existing Processing Capacity
10. Use Existing Data Storage
11. At Wing Stimulation
Importance
Rank
Open
System
Design
Open
Data
Transport
Protocols
Real-time
Signal
Monitoring
Real-Time
Data
Collection
Real-time
Signal
Processing
Onboard
Data
Storage
Onboard
Reasoning
At
Wing
Processing
At
Wing
Stimulation
Use
Existing
Processing
Capacity
Use
Existing
Data
Storage
Minimal Onboard Hardware 7 5 3 5 5 5
Minimize Hardware Cost 8 2 2 2 5 5
Minimize Recertification 7 2 5 5
Facilitate Current Equip. 9 2 3 2 2 2 2
Data Continuity 10 5 5 5
Reusable Modules 9 5 5 1
Detect and Isolate Problems 10 5 5 5 3 3 3 2
Reduce NFF 7 3 5 3 5 2 3 2
Reduce CND 8 3 5 3 5 2 3 2
Reduce RTOK 7 3 5 3 5 2 3 2
Logistics Trigger 6 5 5 5
Enable Reconfiguration 6 5 5 5
Dynamic Recoverability 7 5 5 5 5
Graceful Degradation 8 5 3 5 2
194 203 156 249 181 295 164 130 117 128 128
0.11 0.11 0.09 0.14 0.10 0.16 0.09 0.07 0.06 0.07 0.07
Integration
Performance
Enhanced
Performanc
e
Customer
Requirements
Technical
Requirements
+ +
+
+
+
+
+
+
– –
–
–

19. 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4
Onboard Capture + D&P Processing
Onboard Capture/At Wing Processing
Onboard Capture+Reconfigurable Tests
BIT only + At Wing Stimulation
1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4
Onboard Capture + D&P Processing
Onboard Capture/At Wing Processing
Onboard Capture + Reconfigurable TPS
BIT only + At Wing Stimulation
Full Functionality Problem Type
Partial Functionality 1 Binary Fault
Limited Funtionality 2 Intermittent but Repeatable
Very Limited Functionality 3 Intermittent but Pseudo-Random
No Functionality 4 Graceful Degradation
Predictive
Prognostics
Onb. Impact
Assessment
Dynamic
Recovery
Diagnostic
Processing
Ambiguity
Reduction
Op. Decision
Support
Coupled
IETM
Problem
Isolation
Problem Type Problem Type
Logistics
Trigger
Maintenance
Planning
PHM Approach
Problem Type
Problem Type
Problem Type Problem Type
Problem Type
Basis and Relative Evaluation of Functionality for any System
PHM Approach
Problem Type Problem Type Problem Type Problem Type
Anomaly
Detection

20. • During System Design and Development (SDD) phase and
run parallel to the mainstream design effort
– 80% of Total Life Cycle Costs are “fixed” at the end of SDD
– Systems need to be plumbed with a PHM baseline system
• Initial development costs relatively low when compared with TOC
• Avoids costly retrofits after production and deployment
• Accuracy and Reliability of system will grow over time with minimal
investment
• May allow tradeoff of design margins if PHM design provides real time
monitoring
– Sensor augmentation and data publishing requirements should be
determined early so that prognostics growth can occur
– PHM must be synchronized with PBL planning so that PBL risks can
be fairly evaluated by senior executives
– This is a paradigm shift for many
• Service life extension and similar upgrade programs are
other good options – make sure the ground station
infrastructure and maintenance/logistics follow