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RISK ASSESSMENT

RISK ASSESSMENT. Risk Assessment. Definition: “Risk…merely identifies the undesirable events that might take place during the project” [Jalote, 1998] Three Types: Cost risk Performance Risk Schedule Risk. Risk Assessment. Major Risks Encountered in SD Vague Requirements

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RISK ASSESSMENT

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  1. RISK ASSESSMENT

  2. Risk Assessment • Definition: “Risk…merely identifies the undesirable events that might take place during the project” [Jalote, 1998] • Three Types: • Cost risk • Performance Risk • Schedule Risk

  3. Risk Assessment • Major Risks Encountered in SD • Vague Requirements • Costs and Schedule Estimation • Hidden Costs • Communication Breakdowns • Poor Architecture • Personnel Shortfalls

  4. Software Development- A320 Blunder

  5. Risk Assessment

  6. Risk Reduction • Prototyping • Simulation • Benchmarking • References, Off-the-Shelf Components • Questionnaires • Analytic Modeling

  7. Design Techniques • Standardizing Specification Techniques • UML Modeling Language • SCR/A7-E Specification Technique

  8. Design Techniques • Top Down Functional Decomposition • Information Hiding • Object Oriented Design

  9. Modern Software Development • Move to OO Designs • Formal Modeling Languages • Emphasis on Documentation

  10. Role of Discrete Mathematics • Formal languages for testing systems

  11. Spiral Model Case Study • Purpose: Experimental validation of this approach • The case study involved extending USC’s Integrated Library System to access multimedia archives, including films, maps, and videos.

  12. What were they trying to build/show? • The Integrated Library System is a Unix-based, text-oriented, client-server system designed to manage the acquisition, cataloging, public access, and circulation of library material. • The study’s specific goal was to evaluate the feasibility of using the spiral model to build applications written by USC graduate student teams.

  13. Cycles of the Spiral Model • Cycle 0. Determine the feasibility of an appropriate family of multimedia applications. • Cycle 1. Develop life-cycle objectives (LCO milestone), prototypes, plans, and specifications for individual applications and verify the existence of at least one feasible architecture for each application. • Cycle 2. Establish a specific, detailed life-cycle architecture (LCA milestone), verify its feasibility, and determine that there are no major risks in satisfying the plans and specifications. • Cycle 3. Achieve a workable initial operational capability (IOC milestone) for each project

  14. Results • From the 16 projects in the first semester, the clients selected five applications for development according to the library’s commitment to sustain them after the second semester (IOC). Four are now transitioning to library operations, and the fifth has good prospects for transition after refinement this summer. • The librarians were delighted with the final presentations.

  15. Lessons Learned • The most important outcome of product definition is not a rigorous specification, but a team of stakeholders with enough trust and shared vision to adapt effectively to unexpected changes. • Don’t finish negotiations before prototyping. If you do, the agreements destabilize once the clients see the prototypes. • For projects of this size, using a single cycle each for the LCO and LCA milestones was about right.

  16. Software Development as a Business Process

  17. State of the Market Today:The Frenzy, The Freeze, And After Frenzy Of Technology Spending State Of The Market Today Freeze In Technology Decisions Dot-com Boom Infrastructure Boom Click-And-Mortar Race Dot-com Bust Infrastructure Crash Click-And-Mortar Survival Real E-Business Build Resilient IT Strategic New Initiatives Strong Economy Internet Euphoria Time-to-market Demands Quick Buying Decisions Weak ROI Models Weak Economy Shrinking Revenues Focus on IT Cost Control Business Outlook Unclear Projects Frozen / On Hold US: Slow Recovery EU: Flat Market Challenging Stock Market Selective Projects Decision Cycles Improving Focus on ROI Justification Growing Demand For Outsourcing

  18. The 1980 Letter to The CEO of Ericsson* • The component-based development approach used for AKE/AXE will evolve into a world standard • Go further in three steps • 1983: a standard method including a modeling language and a process, supported by a first generation tool-set • 1985: the modeling language becomes a formal executable language • 1990: expert system on top of software process and development tool; “end-user programming” * Björn Svedberg

  19. Component-Based Architectures • Originated 1967-70 at Ericsson • for real-time, distributed systems: • blocks a k o components, • design • code • executables • run-time objects • interfaces based on signals, • functions crossed blocks -- or realized as collaborations among blocks • Components have become the standard. • No new development paradigm to replace components in sight!

  20. Modeling Languages • 1967-70: The AKE/AXE modeling language: • block diagrams • collaboration diagrams • sequence diagrams • state transition diagrams (state overviews, activity diagrams, concurrent states) • 1974-82: the first object modeling standard SDL adopts those techniques • nicknamed ‘The Ericsson Language’ • In parallel Entity-Relationship modeling emerged • 1987: Objectory modeling language combined SDL and ER technologies, added Use Cases and Multi-Modeling. • 1996: The Unified Modeling Language • based on Objectory, Booch and OMT from 1991 • plus many other modeling ideas • The standard modeling language • UML 2.0 a major new release, followed by more...

  21. Development Process • 1967-70 The AKE/AXE method • functional spec’s • software architecture description • functional descr’s, block descriptions, separate from interface (signal) descriptions • functional tests and system test • 1987-95 The Objectory Process • engineered process to facilitate specializations and instantiations (projects) • use cases drive the business track, the system track and the user track • 1996-2000: The Rational Unified Process • iterative development • architecture-centric • tool support for process engineering and process instantiations • de-facto standard for e-development

  22. Future of Software • We have the standard modeling language • We have a standard development process • What next? • A Software Component Marketplace • Quality from the Beginning • Give Soul to Software Process • A Complete UML Based Software Platform

  23. A Software Component Marketplace • A component industry including • Component factories provide ‘components’ • System Integrators reuse these ‘components’ • ‘Components’ are component systems used to build families of application systems • We need a standard for playing on this marketplace • How to design for reuse • How to design with reuse

  24. Reuseable Assets • Reuse of all models, that is of everything • architecture -- most important but just a fraction of what is reusable • use cases, analysis, design, implementation and test • user interface models, business models, etc. • Reuse of technology • process with tools • projects • guidelines

  25. The Reuse Initiative: e-Development Accelerator Technology or domain specific reusable assets with associated guidelines on usage. ReusableFrameworks Reuse Standards Open UML-based standard expressing how to document and produce reusable assets. Automation Tool support for creating, managing, and reusing software assets.

  26. Component System Component System Component System Application System Component System Application System Component System Component System Component System Application System Layered System Architecture Examples of reusable object Application-specific layer Car Sales Management Customer profileOrder management Application-general layer Shopping cartCredit card authorization Middleware layer System-software layer Object persistency mechanism

  27. Quality from the Beginning We have lost two generations of developers who think they just need to debug at the end, when they instead shouldn’t introduce any defects along the way. • An attitude problem • “bugs are nice, defects are bad” • “some developers make the dirt, others (customers) clean up” • Process change • verify and test along the way -- activity-based verification • there is no test model, test artifacts are part of all models • New tools • generate test cases from requirements, analysis, design...

  28. Activity-Based Verification Whatever you do, you are not done until you have verified that you did what you wanted to do. • Introduce verification on activities • Each activity-artifact pair needs a Verification Case • Each Verification Case has a corresponding Verification Step • Test Cases are specializations of Verification Cases, related to the executable system

  29. Software Process Comes Alive Development steps • The process at your fingertips • The process gets soul • the third step 20 years ago • a software engineering breakthrough technology

  30. Rational Unified Process (RUP) Is specialized to My Unified Process Is enacted as My Project And to My tasks The Process at Your Fingertips

  31. Static Dynamic Process gets soul: people may be humans Traditional processes hold static rules and regulations, but lacks “soul” and adaptive capabilities. They appeal to structured reasoning, but not to the creative (lateral) spirit. Creative Reuse Streamlined and Personalized Short-Term Do Structured Re-Invent Generic Long-Term Learn

  32. Agents Software Components, but… • Autonomous • Pro-Active • Encapsulate Knowledge as Rules • Adaptive Agent (in software)

  33. Each Developer has its Own Personal Agent Personal Agent (for Joe) Joe (Developer) Individuals play roles in software development www.jaczone.com

  34. Every Role in RUP is Matched to One Agent Agent System Role Agent (for System Analyst) www.jaczone.com System Analyst

  35. Personal Agents and Role Agents Agent System Role Agent (for System Analyst) Joe (Developer) Personal Agent (for Joe) Role Agent (for Business-Process Analyst) Since a developer can play many roles his/her personal agent may collaborate with several role agents

  36. Specialist Agents • Rule agents • Reuse agents suggest candidate patterns, frameworks, etc • Workflow agents suggest micro-activities based on state • Conversation agents for conversational modeling • Model completion agents • Round-trip modeling agents between all kinds of models • Evaluation agents • Broker agents www.jaczone.com

  37. A Complete UML Based Platform • An executable UML • a programming language (or a set of PL’s) • Java, C++ become superfluous • combines graphical and program-like syntax • Semantics of changes -- functional and structural -- defined by UML • language defined configuration and version management • Removing seams (or gaps) between UML and • operating systems and database mgmt systems • computer architectures "Function Distribution in Computer System Architectures”, Harold “Bud” Lawson, 1976

  38. Every Layer of Components described in UML • Systemware components • operating systems • database management systems • Middleware components • Customer relationship management • Content management • Change management • Application general components • Subscriber management • Digit analysis node • Route data

  39. Trend: Focus moves upwards Analysis Req.ts Design Impl. Test More “generation”=work elimination • Use cases generate test cases and input to analysis • Analysis will generate implementation; design will become superfluous Now Tomorrow

  40. Summary Tomorrow, Life will be Much Better! We have UML, RUP and tools • Eventually we will get a Component Industry • We will do things right from the beginning • Process will get soul -- developers are people and people are humans • We will get rid of seams and gaps between levels

  41. Readings by Ivar Jacobson • Unified Software Development ProcessJacobson, Booch, Rumbaugh, Addison Wesley Longman (1999) • Object-Oriented Software Development--A Use Case Driven Approach (Addison Wesley)Ivar Jacobson, Addison Wesley Longman (1992) • The Object Advantage: Business Process Reengineering with Objects (Addison Wesley)Ivar Jacobson, Addison Wesley Longman (1994) • Software Reuse: Architecture, Process and Organization for Business Success (Addison Wesley) Ivar Jacobson, Addison Wesley Longman (1997) • The Road to the Unified Software Development Process Ivar Jacobson, Stefan Bylund, Cambridge University Press, 2000

  42. Special readings • Software Reuse: Architecture, Process and Organization for Business Success (Addison Wesley) Ivar Jacobson, Addison Wesley Longman (1997) • Function Distribution in Computer System Architectures, Harold “Bud” Lawson (1976)

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