risk assessment. risk assessment definition: “risk…merely identifies the undesirable events that...
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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 Costs and Schedule Estimation
Hidden Costs Communication Breakdowns Poor Architecture Personnel Shortfalls
Risk Reduction
Prototyping Simulation Benchmarking References, Off-the-Shelf
Components Questionnaires Analytic Modeling
Design Techniques
Standardizing Specification Techniques
UML Modeling Language SCR/A7-E Specification Technique
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.
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.
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 individualapplications and verify the existence of atleast one feasible architecture for each application.
Cycle 2. Establish a specific, detailed life-cyclearchitecture (LCA milestone), verify its feasibility,and determine that there are no major risks insatisfying the plans and specifications.
Cycle 3. Achieve a workable initial operationalcapability (IOC milestone) for each project
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.
Lessons Learned The most important
outcome of product definition is nota rigorous specification, but a team ofstakeholders with enough trust andshared vision to adapt effectivelyto 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.
State of the Market Today:The Frenzy, The Freeze, And After
Freeze In Technology Decisions
State Of The Market Today
Frenzy Of Technology Spending
Dot-com BoomInfrastructure Boom
Click-And-Mortar Race
Dot-com BustInfrastructure Crash
Click-And-Mortar Survival
Real E-BusinessBuild Resilient IT
Strategic New Initiatives
Strong EconomyInternet Euphoria
Time-to-market DemandsQuick Buying Decisions
Weak ROI Models
Weak EconomyShrinking Revenues
Focus on IT Cost ControlBusiness Outlook UnclearProjects Frozen / On Hold
US: Slow RecoveryEU: Flat Market
Challenging Stock MarketSelective Projects
Decision Cycles ImprovingFocus on ROI Justification
Growing Demand For Outsourcing
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* Björn Svedberg
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!
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...
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
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
A Software Component MarketplaceA component industry including
Component factories provide ‘components’ System Integrators reuse these ‘components’ ‘Components’ are component systems used
to build families of application systemsWe need a standard for playing on this marketplace
How to design for reuse How to design with reuse
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
Reuseable AssetsReuseable Assets
The Reuse Initiative: e-Development Accelerator
ReusableFrameworksReusableFrameworksReuse StandardsReuse Standards
AutomationAutomation
Open UML-based standard Open UML-based standard expressing how to document expressing how to document and produce reusable assets.and produce reusable assets.
Open UML-based standard Open UML-based standard expressing how to document expressing how to document and produce reusable assets.and produce reusable assets.
Technology or domain specific Technology or domain specific reusable assets with associated reusable assets with associated guidelines on usage.guidelines on usage.
Technology or domain specific Technology or domain specific reusable assets with associated reusable assets with associated guidelines on usage.guidelines on usage.
Tool support for creating, Tool support for creating, managing, and reusing managing, and reusing software assets.software assets.
Tool support for creating, Tool support for creating, managing, and reusing managing, and reusing software assets.software assets.
ComponentSystem
ComponentSystem
ComponentSystem
ApplicationSystem
ApplicationSystem
ApplicationSystem
ComponentSystem
ComponentSystem
Layered System Architecture
Car Sales ManagementCar Sales
Management
Customer profileOrder managementCustomer profile
Order management
Shopping cartCredit card
authorization
Shopping cartCredit card
authorization
Object persistency mechanism
Object persistency mechanism
Examples of Examples of reusable objectreusable object
Application-general layer
Middleware layer
Application-specificlayer
System-softwarelayer
ComponentSystem
ComponentSystem
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...
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
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
The Process at Your Fingertips
Rational Unified Process
(RUP)
My Unified Process
My Project
My tasks
Is specialized to
Is enacted as
And to
Process gets soul: people may be humans
Static Dynamic
StructuredRe-Invent
GenericLong-Term
Learn
CreativeReuseStreamlined and PersonalizedShort-TermDo
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.
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.
Software Components, but… Autonomous Pro-Active Encapsulate Knowledge as Rules Adaptive
Agents
Agent(in software)
Each Developer has its Own Personal Agent
Personal Agent(for Joe)
Joe(Developer)
Individuals play roles in software development
Individuals play roles in software development www.jaczone.com
Every Role in RUP is Matched to One Agent
System Analyst
Role Agent(for System Analyst)
Agent System
www.jaczone.com
Personal Agents and Role Agents
Personal Agent(for Joe)
Joe(Developer)
Role Agent(for System Analyst)
Role Agent(for Business-Process Analyst)
Agent System
Since a developer can play many roles his/her personal agent may collaborate with several role agentsSince a developer can play many roles his/her personal agent may collaborate with several role agents
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 agentswww.jaczone.com
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
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"Function Distribution in Computer System Architectures”, Harold “Bud” Lawson, 1976
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
Trend: Focus moves upwards
Use cases generate test cases and input to analysis
Analysis will generate implementation; design will become superfluous
Req.ts Impl. TestAnalysis Design
More “generation”=work elimination
NowNow
TomorrowTomorrow
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
SummarySummary
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