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Constructive System of Systems Integration Cost Model (COSOSIMO)******************Tutorial
Jo Ann Lane, [email protected]
USC Center for Systems & Software Engineering
http://csse.usc.edu23 October 2006
2
Overview
COSOSIMO Background
System of Systems (SoS) and SoS Engineering (SoSE) Environment
Current COSOSIMO Cost Estimation Approach
Conclusions
References
3
COCOMO Cost Model Suite Overview*
* Barry Boehm, Ricardo Valerdi, Jo Ann Lane, and Winsor Brown, “COCOMO Suite Methodology and Evolution”, CrossTalk, April 2005.
4
Analyze existing literature
Step 1 Perform Behavioral analysesStep 2 Identify relative
significance
Step 3 Perform expert-judgment Delphi assessment, formulate a-priori modelStep 4
Gather project data
Step 5
Determine Bayesian A-Posteriori modelStep 6
Gather more data; refine modelStep 7
Concurrency and feedback implied…
USC-CSE Modeling Methodology*
* Boehm, et. al., Software Cost Estimation with COCOMOII, 2000.
5
Goal of Research
Develop a cost model (COSOSIMO) to – Support the estimation of effort associated with
System-of-System Engineering (SoSE) May be performed by one or more Lead System
Integrator (LSI) organizations– Complement the other USC CSE cost models for
software development, system engineering (SE), and Commercial-Off-the-Shelf (COTS) integration, leading toward a more comprehensive and unified cost model to support the much broader system of interest life cycleCOSOSIMO will not estimate the total SoS development
costs, but rather just the SoSE costs at the SoS level…
6
History of COSOSIMO Model
Early 2003 Potential need for SoSE cost model identified
Fall/Winter 2003 Initial model developed based on software size
Fall 2004 Early design model based of SoS architecture characteristics (not software size)
Spring/Summer 2005
EIA 632-based survey conducted to determine SoSE differences from traditional systems engineering
Fall 2005 SoSE WBS analysis
Fall/Winter 2005 2-submodel version of COSOSIMO investigated
Spring/Summer 2006
SoSE-specific characteristics captured from SoSE conferences/workshops
Spring 2006 3-submodel version of COSOSIMO proposed
7
What is a “System-of-Systems”?
Very large systems developed by creating a framework or architecture to integrate component systems
SoS component systems independently developed and managed– New or existing systems– Have their own purpose– Can dynamically come and go from SoS
SoS exhibits emergent behavior not otherwise achievable by component systems
SoS activities often planned and coordinated by a Lead System Integrator (LSI)
Typical domains– Business: Enterprise-wide and cross-enterprise integration to support
core business enterprise operations across functional and geographical areas
– Military: Dynamic communications infrastructure to support operations in a constantly changing, sometimes adversarial, environment
INCOSE Handbook Definition: “Systems of Systems” are defined as an interoperating collection of component systems that produce results unachievable by the individual systems alone. (Krygiel 1999)
8
What is a “Lead System Integrator”?
Organization (or set of organizations) selected to accomplish the definition and acquisition of SoS components, and the continuing integration, test, and evolution of the components and SoS
Typical activities– Lead concurrent engineering of requirements, architecture, and plans– Identify and evaluate technologies to be integrated– Conduct source selection– Coordinate supplier activities and validate SoS architecture feasibility– Integrate and test SoS-level capabilities– Manage changes at the SoS level and across the SoS-related IPTs– Manage evolving interfaces to external systems
Typically do not develop system components to be integrated (possible exception: SoS infrastructure)
9
What is SoSE
USAF SAB Report on SoSE for Air Force Capability (USAF 2005): The process of planning, analyzing, organizing, and integrating the capabilities of a mix of existing and new systems into a system-of-systems capability that is greater than the sum of the capabilities of the constituent parts. This processes emphasizes the process of discovering, developing, and implementing standards that promote interoperability among systems developed via different sponsorship, management, and primary acquisition processes.
National Centers for Systems of Systems Engineering (NCOSOSE): The design, deployment, operation, and transformation of metasystems that must function as an integrated complex system to produce desirable results. These metasystems are themselves comprised of multiple autonomous embedded complex systems that can be diverse in technology, context, operation, geography, and conceptual frame. (http://www.eng.odu.edu/ncsose/what_is_SOSE.shtml)
10
What is SoSE (continued)
Wikipedia (http://en.wikipedia.org/wiki/System_of_Systems_Engineering): SoSE is a set of developing processes and methods for designing and implementing solutions to System-of-Systems problems. SoSE is relatively new term being used in Department of Defense applications, but is increasingly being applied to non-military/security related problems (e.g. transportation, healthcare, internet, search and rescue, space exploration). SoSE is more than systems engineering of complex systems because design for System-of-Systems problems is performed under some level of uncertainty in the requirements and the constituent systems, and it involves considerations in multiple levels and domains.
SoSE and Systems Engineering are related but different fields of study. Where as systems engineering addresses the development and operations of products, SoSE addresses the development and operations of programs. In other words, traditional systems engineering seeks to optimize an individual system (i.e., the product), while SoSE seeks to optimize network of various systems brought together to meet specific program's (i.e., the SoS problem's) objectives. SoSE enables decision-makers to understand the implications of various choices; thus, SoSE methodology seeks to prepare the decision-makers for effective architecting of System-of-Systems problems.
Due to varied methodology and areas of applications in existing literature, there is no unified consensus for processes involved in System-of-Systems Engineering. One of the proposed SoSE frameworks, by Dr. Daniel A. DeLaurentis, recommends a three-phase method where a SoS problem is defined (understood), abstracted, modeled and analyzed for behavioral patterns.
11
SoSE Compared to Traditional SE Activities
Traditional SE Activities (EIA/ANSI 632) – Acquisition and supply
Product Supply Product Acquisition Supplier Performance
– Technical management Process Implementation Strategy Technical Effort Definition Schedule and Organization Technical Plans Work Directives Progress Against Plans and Schedules Progress Against Requirements Technical Reviews Outcomes Management Information Dissemination
– System design Acquirer Requirements Other Stakeholder Requirements System Technical Requirements Logical Solution Representations Physical Solution Representations Specified Requirements
Traditional SE Activities (continued)
– Product realization Implementation Transition to Use
– Technical evaluation Effectiveness Analysis Tradeoff Analysis Risk Analysis Requirements Statements Validation Acquirer Requirements Validation Other Stakeholder Requirements
Validation System Technical Requirements
Validation Logical Solution Representations
Validation Design Solution Verification End Product Verification Enabling Product Readiness End Products Validation
12
SoSE Compared to Traditional SE Activities (continued)
Key Areas Where SoSE Activities Differ From Traditional Systems Engineering – Architecting composability vs. decomposition (Meilich
2006)– Added “ilities” such as flexibility, adaptability, composability
(USAF 2005)– Net-friendly vs. hierarchical (Meilich 2006)– First order tradeoffs above the component systems level
(e.g., optimization at the SoS level, instead of at the component system level) (Garber 2006)
– Early tradeoffs/evaluations of alternatives (Finley 2006)– Human as part of the SoS (Siel 2006, Meilich 2006, USAF
2005)– Discovery and application of convergence protocols (USAF
2005)
13
SoSE Compared to Traditional SE Activities (continued)
Key Areas Where SoSE Activities Differ From Traditional Systems Engineering (continued)
– Organizational scope defined at runtime instead of at system development time (Meilich 2006)
– Dynamic reconfiguration of architecture as needs change (USAF 2005)
– Modeling and simulation, in particular to better understand “emergent behaviors” (Finley 2006)
– Component systems separately acquired and continue to be managed as independent systems (USAF 2005)
– Intense concept phase analysis followed by continuous anticipation; aided by ongoing experimentation (USAF 2005)
14
SoSE Compared to Traditional SE Activities (continued)
Key Challenges for SoSE– Business model and incentives to encourage working
together at the SoS level (Garber 2006)– Doing the necessary tradeoffs at the SoS level (Garber
2006)– Human-system integration (Siel 2006, Meilich 2006)– Commonality of data, architecture, and business strategies
at the SoS level (Pair 2006)– Removing multiple decision making layers (Pair 2006)– Requiring accountability at the enterprise level (Pair 2006)– Evolution management (Meilich 2006)– Maturity of technology (Finley 2006)
For the most part, SoSE appears to be SE+
15
Sample Dynamic SoS:Metropolitan Area Crisis Management System
Net - Centric SoS Net-CentricConnectivity
16
Sample “Steady-State” SoS: Enterprise Wide Integration of Core Business Applications
Supplier 1 Supplier n
•••
•••
Net-CentricConnectivity
Net-CentricConnectivity
Net-CentricConnectivity
• • •
17
System of Systems Cost Estimation
SOS
SmS2 (SoS)S1
S11 S12 S1n S21 S22 S2n Sm1 Sm2 Smn
……
…… …… ……
Level 0
Level 1
Level 2
Activity Levels Cost Model
SoS Lead System Integrator Effort (SoS scoping, planning, requirements, architecting; source selection; teambuilding, re-architecting, feasibility assurance with selected suppliers; incremental acquisition management; SoS integration and test; transition planning, preparation, and execution; and continuous change, risk, and opportunity management)
Level 0, and other levels if lower level systems components are also SoSs (e.g., S2)
COSOSIMO
Development of SoS Software-Intensive Infrastructure and Integration Tools Level 0 COCOMO II
System Engineering for SoS Components Levels 1-n COSYSMO
Software Development for Software-Intensive Components Levels 1-n COCOMO II
COTS Assessment and Integration for COTS-based Components Levels 1-n COCOTS
18
System of Systems Cost Model
Size Drivers
Cost Drivers
SoSDefinition andIntegrationEffort
Calibration
COSOSIMO
Characteristics of SoSs supported by cost model– Strategically-oriented stakeholders interested in tradeoffs and costs– Long-range architectural vision for SoS– Developed and integrated by an LSI– System component independence
Size drivers and cost drivers– Based on product characteristics, processes that impact LSI effort,
and LSI personnel experience and capabilities
19
Proposed Size Drivers
Number of SoS-related requirements Number of of distinct interface protocols to be provided by the SoS
framework Number of independent system component organizations that are providing
system components that will operate within the SoS framework Number of SoS user scenarios Number of unique component systems
S1
S2
S3
S4Each weighted by complexity…
20
Conceptual LSI Effort Profile
Planning, Requirements Management, and Architecting
Source Selection and Supplier Oversight
SoS Integration and Testing
Inception Elaboration Construction Transition
• LSI activities focus on three somewhat independent activities, performed by relatively independent teams
• A given LSI may be responsible for one, two, or all activity areas• Some SoS programs may have more than one organization performing LSI
activities
21
Planning, Requirements Management,
and Architecting (PRA)
Source Selection and Supplier
Oversight (SO)
SoS Integrationand Testing
(I&T)
Size Drivers
Cost Drivers
SoSDefinition andIntegrationEffort
COSOSIMO Reduced Parameter Sub-Model Overview
22
Planning, Requirements Management,
and Architecting
Size Drivers• # SoS-related requirements• # SoS interface protocols
Cost Drivers• Requirements understanding• Level of service requirements• Stakeholder team cohesion• SoS team capability• Maturity of LSI processes• Tool support• Cost/schedule compatibility• SoS risk resolution
COSOSIMO: PRA Sub-Model
LSI PRAEffort
23
COSOSIMO PRA Effort Estimation
m n
SoS PRAPM = APRA[ CREQi + CIPj]BPRA
i=1 j=1Where:
PRAPM LSI Planning, Requirements Management, and Analysis effort in person-
monthsAPRA Constant derived from PRA historical dataCREQi Complexity factor associated with the ith SoS requirement
CIPj Complexity factor associated with the jth SoS interface protocol
m Number of SoS-related “sea-level” requirementsn Number of interface protocols supported by the SoS architectureBPRA Effort exponent based on the PRA exponential scale factors. The geometric
product of the scale factors results in an overall exponential effort adjustment factor to the nominal PRA effort
24
Source Selection and
Supplier Oversight
Size Drivers• # independent component
system organizations
Cost Drivers• Requirements understanding• Architecture maturity• Level of service requirements• SoS team capability• Maturity of LSI processes• Tool support• Cost/schedule compatibility• SoS risk resolution
COSOSIMO: SO Sub-Model
LSI SOEffort
25
COSOSIMO SO Effort Estimation
n
SoS SOPM = ASO[ CSCOj]BSO
j=1Where:
SOPM LSI Source Selection and Supplier Oversight effort in person-months
ASO Constant derived from SO historical dataCSCOj Complexity factor associated with the jth SoS component system organization
n Number of organizations providing independently developed and maintained system components for the SoS
BSO Effort exponent based on the SoS SO exponential scale factors. The geometric product of the scale factors results in an overall exponential effort adjustment factor to the nominal SO effort
26
SoS Integrationand Testing
Size Drivers• # SoS interface protocols• # SoS scenarios• # unique component systems
Cost Drivers• Requirements understanding• Architecture maturity• Level of service requirements• SoS team capability• Maturity of LSI processes• Tool support• Cost/schedule compatibility• SoS risk resolution• Component system maturity and
stability• Component system readiness
COSOSIMO: I&T Sub-Model
LSI I&TEffort
27
COSOSIMO I&T Effort Estimation
q r s
SoS I&TPM = AI&T[ CIPi + CSCENj + CSCOk]BI&T
i=1 j=1 k=1Where:
I&TPM LSI Integration and Test effort in person-months
AI&T Constant derived from I&T historical dataCIPi Complexity factor associated with the ith SoS interface protocol
CSCENj Complexity factor associated with the jth SoS interface protocolCSCOk Complexity factor associated with the kth SoS component system organization
q Number of interface protocols supported by the SoS architecturer Number of SoS scenarioss Number of organizations providing independently developed and maintained
system components for the SoSBI&T Effort exponent based on the I&T exponential scale factors. The geometric
product of the scale factors results in an overall exponential effort adjustment factor to the nominal I&T effort
28
COSOSIMO Total SoSE Effort Estimation
SoSEPM = PRAPM + SOPM + I&TPM
Where:
PRAPM LSI Planning, Requirements Management, and Analysis effort in person-
months
SOPM LSI Source Selection and Supplier Oversight effort in person-months
I&TPM LSI Integration and Test effort in person-months
29
SoS Schedule Estimation
Customer,Users
LSI – Agile
LSI IPTs – Agile
Suppliers – Agile
Suppliers – PD – V&V
LSI – Integrators
RFP, SOW, Evaluations, ContractingEffort/Staff
Proposals
Similar, withadded change
traffic fromusers…
Ass
ess
co
mpati
bili
ty,
short
-fa
lls
Rew
ork
LC
O
LC
APack
ages
at
all
levels
COSOSIMO-like
Assess sources of change;
Negotiate rebaselined
LCA2 package at all levels
COSOSIMO-like
Similar, withadded re-
baselineing risks and rework…
InceptionElaboration
Source SoS Selection Architecting
Increment 1 Increments 2,… n
Develop to spec, V&V
CORADMO-like
Degree of Completeness
risks, rework
Proposal Feasibility
LCO LCA
LCA1
IOC1
Effort/staffat all levels
risks, rework
Risk-manage slow-
performer, completenes
s
risks, rework
Integrate
COSOSIMO-like
LCA2 shortfalls
risks, rework
Effort COSYSMO-like.
Schedule = Effort/Staff
Try to model ideal staff size
LCA2
30
Conclusions
Traditional systems engineering takes too long and too much effort LSIs are finding better ways to engineering SoSs (SoSE) Many combine agile with traditional approaches
– Increases concurrency– Reduces risk– Compresses schedules
Reduced-parameter set COSOSIMO captures effects of new processes in three key areas– Planning, requirements management, and architecting– Source selection and supplier oversight– SoS integration and testing
Sub-models have fewer parameters that are more tailored to associated SoSE activities
Allows LSIs to estimate areas of interest and conduct “what ifs” comparisons of different development strategies
31
Conclusions (continued)
With the addition of a new COSOSIMO cost model to existing cost model tools, it will be possible to get more complete estimates of the SoS development effort
Key to this process is – Having an SoS architecture sufficiently defined so that component
system modifications to support operation in the SoS environment can be made with few dependencies on other SoS development efforts
– Structuring the WBS so that SoS and component system tasks can be decomposed into parts
that can be estimated using the existing cost model tools Parts not covered by cost models can be clearly identified and
estimated using non-parametric methods Expected COSOSIMO availability: Fall 2007
“All models are wrong, but some of them are useful” (W. E. Deming)
32
What is Needed to Support Fall 2007 Availability
Participation in current SoSE surveys Data from both SoS and SE programs
– Process descriptions to help understand the differences between SoSE and SE
– Effort data to calibrate COSOSIMO (either standalone model or special calibration of COSYSMO)
For those organizations that provide SoSE effort from at least 3 SoS projects,
a local calibration will be provided…
33
COSOSIMO-Related References
Boehm, B., et al. (2000); Software Cost Estimation with COCOMO II; Prentice HallBoehm,B., Valerdi, R., Lane, J., and Brown, W. (2005); COCOMO Suite Methodology and
Evolution; CrossTalk, Vol. 18, No. 5 (pp. 20-25)Boehm, B., and J. Lane (2006); “21st Century Processes for Acquiring 21st Century
Systems of Systems; CrossTalk Vol. 19, No. 5 (pp. 4-9)Lane, J. (2005); System of Systems Lead System Integrators: Where do They Spend
Their Time and What Makes them More/Less Efficient; USC-CSE-TR-2005-508Lane, J. (2005); Factors Influencing System-of-Systems Architecting and Integration
Costs; Conference on Systems Engineering Research Lane, J (2006); COSOSIMO Parameter Definitions, USC-CSE-TR-2006-606Lane, J and Boehm, B. (2006); Synthesis of Existing Cost Models to Meet System of
Systems Needs; Conference on Systems Engineering ResearchLane, J and Boehm, B. (2006); System-of-Systems Cost Estimation: Analysis of Lead
System Integrator Engineering Activities; InterSymposium Symposium on Information Systems Research and Systems Approach
Lane, J and Valerdi, R (2005); Synthesizing SoS Concepts for Use in Cost Estimation; IEEE Systems, Man, and Cybernetics
34
SoSE-Related References
Carlock, P.G., and R.E. Fenton, "System of Systems (SoS) Enterprise Systems for Information-Intensive Organizations," Systems Engineering, Vol. 4, No. 4, pp. 242-261, 2001
DiMario, Mike (2006); “System of Systems Characteristics and Interoperability in Joint Command Control”, Proceedings of the 2nd Annual System of Systems Engineering Conference
Electronic Industries Alliance (1999); EIA Standard 632: Processes for Engineering a SystemFinley, James (2006); “Keynote Address”, Proceedings of the 2nd Annual System of Systems Engineering
Conference Garber, Vitalij (2006); “Keynote Presentation”, Proceedings of the 2nd Annual System of Systems
Engineering ConferenceINCOSE (2006); Systems Engineering Handbook, Version 3, INCOSE-TP-2003-002-03Krygiel, A. (1999); Behind the Wizard’s Curtain; CCRP Publication Series, July, 1999, p. 33Maier, M. (1998); “Architecting Principles for Systems-of-Systems”; Systems Engineering, Vol. 1, No. 4 (pp
267-284)Meilich, Abe (2006); “System of Systems Engineering (SoSE) and Architecture Challenges in a Net Centric
Environment”, Proceedings of the 2nd Annual System of Systems Engineering ConferencePair, Major General Carlos (2006); “Keynote Presentation”, Proceedings of the 2nd Annual System of
Systems Engineering Conference Proceedings of AFOSR SoSE Workshop, Sponsored by Purdue University, 17-18 May 2006Proceedings of Society for Design and Process Science 9th World Conference on Integrated Design and
Process Technology, San Diego, CA, 25-30 June 2006Siel, Carl (2006); “Keynote Presentation”, Proceedings of the 2nd Annual System of Systems Engineering
ConferenceUnited States Air Force Scientific Advisory Board (2005); Report on System-of-Systems Engineering for Air
Force Capability Development; Public Release SAB-TR-05-04