1. University of Southern California Center for Software Engineering C S E USC Barry Boehm, USC CS 510 Lecture Fall 2011 Value-Based Software Engineering and the Incremental Commitment Spiral Model August 24, 20111© USC-CSSE

2. University of Southern California Center for Software Engineering C S E USC August 24, 2011© USC-CSSE2 Outline VBSE theory and process overview Implementing VBSE via the Incremental Commitment Spiral Model –ICSM nature, origins, and framework –Example commercial application –Decision table for common special cases Conclusions and references

3. University of Southern California Center for Software Engineering C S E USC August 24, 2011© USC-CSSE3 Theory W: Enterprise Success Theorem – And informal proof Theorem: Your enterprise will succeed if and only if it makes winners of your success-critical stakeholders Proof of “if”: Everyone that counts is a winner. Nobody significant is left to complain. Proof of “only if”: Nobody wants to lose. Prospective losers will refuse to participate, or will counterattack. The usual result is lose-lose.

4. University of Southern California Center for Software Engineering C S E USC August 24, 2011© USC-CSSE4 Theory W: WinWin Achievement Theorem Making winners of your success-critical stakeholders requires: i.Identifying all of the success-critical stakeholders (SCSs). ii.Understanding how the SCSs want to win. iii.Having the SCSs negotiate a win-win set of product and process plans. iv.Controlling progress toward SCS win-win realization, including adaptation to change.

5. University of Southern California Center for Software Engineering C S E USC August 24, 2011© USC-CSSE5 Initial VBSE Theory: 4+1 Engine: Theory W (stakeholder win-win): What values are important? –Enterprise Success Theorem –Theory of Justice –Win-Win Equilibrium and Negotiation Four Supporting Theories –Dependency Theory: How do dependencies affect value realization? –Results chains; value chains; cost/schedule/performance tradeoffs –Utility Theory: How important are the values? –Multi-attribute utility; Maslow need hierarchy –Decision Theory: How do values determine decisions? –Investment theory; game theory; statistical decision theory –Control Theory: How to monitor and control value realization –Feedback control; adaptive control; spiral risk control

6. University of Southern California Center for Software Engineering C S E USC August 24, 2011© USC-CSSE6 VBSE Theory 4+1 Structure

7. University of Southern California Center for Software Engineering C S E USC August 24, 2011© USC-CSSE7 Initial VBSE Theory: 4+1 Process – With a great deal of concurrency and backtracking

8. University of Southern California Center for Software Engineering C S E USC Need Incremental Approach to VBSE Process Cannot make all decisions in a single pass –Emergent technology: social networking –Emergent requirements: outdo competitors –TBD standards: information exchange; infrastructure –Evolving platforms: mobile devices –Emerging stakeholders: strategic partners, suppliers Best to incrementally define scope, features, details –But do best-effort architecting for the future Avoid easiest-first increments on large, critical projects Concurrently determine requirements and solutions Best to incrementally develop product features –Avoid obsolete deliveries –Early focus on critical infrastructure, high-value features August 24, 2011© USC-CSSE8

9. University of Southern California Center for Software Engineering C S E USC August 24, 2011 The Broadening Early Cone of Uncertainty (CU) Need greater investments in narrowing CU –Mission, investment, legacy analysis –Competitive prototyping –Concurrent engineering –Associated estimation methods and management metrics Larger systems will often have subsystems with narrower CU’s Global Interactive, Brownfield Batch, Greenfield Local Interactive, Some Legacy 9© USC-CSSE

10. University of Southern California Center for Software Engineering C S E USC August 24, 2011 10 Rapid Change Creates a Late Cone of Uncertainty – Need incremental vs. one-shot development Uncertainties in competition, technology, organizations, mission priorities 10© USC-CSSE

11. University of Southern California Center for Software Engineering C S E USC Animated displays Secondary application functions User amenities Main application functions Natural speech input Tertairy application functions Basic application functions Data management system Operating System InvestmentHigh-payoffDiminishing returns Cost of software product Value of software product to organization Software Production Function August 24, 201111© USC-CSSE

12. University of Southern California Center for Software Engineering C S E USC August 24, 2011© USC-CSSE12 Outline VBSE theory and process overview Implementing VBSE via the Incremental Commitment Spiral Model –ICSM nature, origins, and framework –Example commercial application –Decision table for common special cases Conclusions and references

13. University of Southern California Center for Software Engineering C S E USC August 24, 2011 What is the ICSM? Risk-driven framework for determining and evolving best-fit system life-cycle process Integrates the strengths of phased and risk-driven spiral process models Synthesizes together principles critical to successful system development –Stakeholder value-based system definition and evolution. –Incremental commitment and accountability. –Concurrent hardware-peopleware-software system definition and development. –Evidence and risk-based decision-making. Principles trump diagrams… Principles used by 60-80% of CrossTalk Top-5 projects, 2002-2005 13© USC-CSSE

14. University of Southern California Center for Software Engineering C S E USC August 24, 2011 ICSM Nature and Origins Integrates hardware, software, and human factors elements of systems engineering –Concurrent exploration of needs and opportunities –Concurrent engineering of hardware, software, human aspects –Concurrency stabilized via anchor point milestones Developed in response to systems/software issues –Clarify “spiral development” usage in DoD Instruction 5000.2 Initial phased version (2005) –Explain Future Combat System of systems spiral usage to GAO Underlying process principles (2006) –Provide framework for human-systems integration National Research Council report (2007) Integrates strengths of current process models –But not their weaknesses ©USC-CSSE 14© USC-CSSE

15. University of Southern California Center for Software Engineering C S E USC August 24, 2011 15 Incremental Commitment in Gambling Total Commitment: Roulette –Put your chips on a number E.g., a value of a key performance parameter –Wait and see if you win or lose Incremental Commitment: Poker, Blackjack –Put some chips in –See your cards, some of others’ cards –Decide whether, how much to commit to proceed 15© USC-CSSE

16. University of Southern California Center for Software Engineering C S E USC August 24, 2011 12/31/2007 ©USC-CSSE 16 Scalable Remotely Controlled Operations 16© USC-CSSE

17. University of Southern California Center for Software Engineering C S E USC August 24, 2011 17 Total vs. Incremental Commitment – 4:1 RPV Total Commitment –Agent technology demo and PR: Can do 4:1 for $1B –Winning bidder: $800M; PDR in 120 days; 4:1 capability in 40 months –PDR: many outstanding risks, undefined interfaces –$800M, 40 months: “halfway” through integration and test –1:1 IOC after $3B, 80 months Incremental Commitment [with a number of competing teams] –$25M, 6 mo. to VCR [4]: may beat 1:2 with agent technology, but not 4:1 –$75M, 8 mo. to FCR [3]: agent technology may do 1:1; some risks –$225M, 10 mo. to DCR [2]: validated architecture, high-risk elements –$675M, 18 mo. to IOC [1]: viable 1:1 capability –1:1 IOC after $1B, 42 months 17© USC-CSSE

18. University of Southern California Center for Software Engineering C S E USC August 24, 2011 The Incremental Commitment Life Cycle Process: Overview Anchor Point Milestones Synchronize, stabilize concurrency via FEDs Risk patterns determine life cycle process 18© USC-CSSE

19. University of Southern California Center for Software Engineering C S E USC August 24, 201119© USC-CSSE

20. University of Southern California Center for Software Engineering C S E USC August 24, 201120© USC-CSSE

21. University of Southern California Center for Software Engineering C S E USC August 24, 2011 Example ICSM Commercial Application: Symbiq Medical Infusion Pump Winner of 2006 HFES Best New Design Award Described in NRC HSI Report, Chapter 5 21© USC-CSSE

22. University of Southern California Center for Software Engineering C S E USC August 24, 2011 Symbiq IV Pump ICSM Process - I Exploration Phase –Stakeholder needs interviews, field observations –Initial user interface prototypes –Competitive analysis, system scoping –Commitment to proceed Valuation Phase –Feature analysis and prioritization –Display vendor option prototyping and analysis –Top-level life cycle plan, business case analysis –Safety and business risk assessment –Commitment to proceed while addressing risks 22© USC-CSSE