30 years of Software Engineering : from art to business ?

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30 years of Software Engineering from art to
business ?

• Anne-Marie HUGUESESSI
• University of Nice Sophia Antipolis
• FRANCE

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Background

• Academic research
• compilers
• parallelism
• generic software environments
• distributed objects

• Industry
• corporate Information systems (banking)
• software environments
• OS

• Training
• Software engineering
• Data bases
• Management of Information Systems

3
Agenda

• Introduction
• art /craft/ industry/business
• The software process
• Software components
• Introducing reuse
• software architecture
• changing for reuse

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Dream... Art Business

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Craft industry
Log cabin 1person 1 month

Pont du gard , Nimes, France 1st century after
Jc thousand slaves, 100 years maintained 1992 - 96
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Craft industry
Log cabin 1person 1 month

Montparnasse Tower Paris 1969 - 1972 hundreds of
workers
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Dream
Charles Babbage -1791 -1871 Note on the
application of machinery to the computation of
astronomical and mathematical tables read to the
Royal Astronomical Society on 14 June 1822.

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Meanwhilewhile

Viaduc de Gabarit 1875-1880
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Art

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Meanwhile...
Tancarville bridge France 3 477 000 working hours
1955 - 59
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Industry hardware, economy
IBM PC , 80s still improved
GUI , laptops Apple, Xerox still improved
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Meanwhile
Brotonne bridge France 1974 - 1977
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Industry
methods
1990 networks
1995
1998
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Industry challenge productivity

• Ready to assemble parts
• methods
• tools

Ile de Ré bridge France 1987 - 88
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Industry challenge simulation and tests
Normandie bridge France 1995
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Industry challenge maintenance
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Conclusion

• quicker

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ConclusionArt / research /computer science

• Make it work
• Creativity
• Expertise
• Pleasure
• Quality
• Productivity

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Agenda

• Introduction
• The software process
• software today
• quality attributes
• quality actors
• Software components
• Introducing reuse
• software architecture
• changing for reuse

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Building software
With resources
components
New or changed requirements
New or changed software product
Software Production Process
Legacy system

• Quality attributes

Under constraints
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The software business today everywhere

• Software in the Old economy
• competitive edge
• but small part of budget
• ex
• aeronautics,
• medical equipment
• house appliances, fire alarms
• corporate information systems
• banking

• New (web) economy
• only soft
• (no) time to market
• ex
• e - business

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Old economy

• Management
• Respect of time and budget
• one project at a time
• improved during 20 years

• Problems that may occur
• costs overruns
• delays
• quality factors (standards)
• maintenance (80 of total product)
• decreasing efficiency

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New economy e-.

• Management
• very poor
• start up system

• Problems
• costs overruns
• delays
• specification
• validation
• security

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Quality requirements

• During development
• visibility
• intermediate artifact
• management of the process
• testability
• maintainability
• Traceability

• During maintenance
• accuracy
• performance (time space)
• reliability
• extensibility
• traceability

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Quality Assurance

• Enterprise quality manual
• guide lines, standards
• according to international standards ISO 9000,
  CMM, DOD
• Quality plan
• according to quality manual
• project management
• procedures definition
• quality evaluation (measures)
• training

• Communicate
• between developers
• between clients and providers
• documentation

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Quality Assurance

• Communicate
• between developers
• between clients and providers
• documentation

• Intermediate artifacts
• prototypes
• documents code
• tests
• milestones reviews and inspections
• Errors, defects,
• Omissions, Ambiguities,
• inconsistence
• incorrect hypothèsis,

• Control during
• development
• maintenance
• reports, meetings, reviewing process

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Quality Assurance

• Organize
• the process
• teamwork
• workflow
• tools and methods
• configuration management

• Communicate
• between developers
• between clients and providers
• documentation

• Control during
• development
• maintenance
• reports, meetings, reviewing process

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Quality standards ISO 9000...

• requirements
• complete , frozen,
• before product design
• Visibility
• artifacts
• project management and control
• Traceability
• during development
• during maintenance

Manage client /provider relationship
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Capability maturity model SEI

• Evaluate
• production process
• Position
• on a maturity grid
• 5 levels
• improve
• progressively

Improve internal process
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SPICE Project 1993 Software Process Improvement
and Capability dEtermination

• The project
• ISO 9000, ISO 12207 CMM
• tested since 99
• to be published by ISO in 2001.
• Granularity
• 29 process on a grid of 10 levels (with process
  attributes as sub levels
• 4 states per process not really adopted)

• Completeness
• Complexity
• Comparability
• Applicability
• Conformity

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Quality assurance
How ?
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Software Process Management
process
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Managing the process is managing quality

• WHY
• WHAT
• WHO
• WHEN
• WHERE
• HOW
• life-cycle strategy
• technology methods , tools
• organization

Workflow
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life cycle strategies

• Cartesian approach
• top down
• heuristics
• bottom up

V or waterfall life cycle old economy
(1)
Usable iterations
Operationnal solution
Incremental life cycle prototyping spiral,
fountain model DSDM, RAD new economy
(2)
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Human factors

• creativity
• not invented here syndrom
• Change reluctance

Provide usable tools
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Art or Technology?50 years of computer science
embedded applications e-business
real time applications
Scientific and corporate software batch
networks, Internet Intranet components 3
tiers application server
Personal computer distributed systems client-serve
r data bases objects and classes libraries Unix,
chips
Scientific calculus
FORTRAN COBOL multi usersystem file system real
time
Assembly language ENIAC
1945
1958
1990
2000
1975
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Aiming at Software Factory Components
INTEROPERABILITY
Reuse
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Agenda

• Introduction
• The software process
• Software components
• Components versus objects
• Component reuse
• Introducing reuse to improve quality
• software architecture
• changing for reuse

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Changing for reuse
benefits
Develop quickly new quality products
Reach interoperability
Organize reuse of business components
Extend coverage
Manage reuse
Reduce maintenance costs
Reuse products
Reduce development time
Reuse black box
Reuse code
Time investments experience
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Software reuse

• Why?
• Decrease cost
• Increase quality

• What
• code
• informally (paste)
• macro, functions
• design
• patterns
• expertise
• libraries, frameworks
• GUI
• DBMS
• application generators

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Reuse in practice

• Two ways
• Opportunistic
• reuse pieces of soft that fit the problem and
  happen to be available
• may work
• Planned
• explicit effort made to develop reusable
  artifacts
• the right abstraction
• the right level of variability
• to fit in higher level structure
• should work better

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Reuse in practice (cont)

• bottom up may work
• build pieces
• add them to a collection
• find a suitable piece
• top down should work better
• assets developed as parts fitting in a higher
  level structure
• assets adhere to predefined , provided and
  required interfaces

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Reuse in practice

• reuse software
• over different versions
• of a same product
• reuse components
• over product versions
• and over various product
• reuse components
• over different product versions
• various products
• different organizations

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Classes and objects

• Classes
• Model
• Encapsulation
• data
• methods
• Generic
• Inheritance
• Private Public
• Objects
• a class instance

Account
balance date
consult deposit(amount)
saving
ordinary
Authorized amount
ratio
Calculate Agios
calculate interest
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Component

• Software component
• independent module
• built for reuse
• accessible via an interface
• Container
• area to assemble components
• to build an application

container
buttons components
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Software component facts

• Art / theory
• black box components
• narrow interface, single point of access
• few variation points configured during
  instanciation

• Business/industry
• large piece of code with complex structure
• . object oriented framework
• interface provided by entities
• i.e. classes in the asset
• no explicit difference with non interface
  entities
• variation implemented through
• configuration
• specialisation or replacement of entities of the
  asset

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Software component facts

• Art / theory
• standardized interfaces , can be sold on
  component markets
• focus on functionality
• that can be verified through formal validation

• Business /industry
• developed internally,
• if developed externally must be considerably
  adapted to fit in the product line architecture
• all quality attributes are of eqal importance
  (performance, reliability, maintainability..)

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Component life cycle
Define scope
specify
Support
design
Adopt /reuse
Qualify
develop
validate
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Software Life cycle Component oriented process
requirements
Available components Non executable component
recollection (doc) executable component
recollection (source, tests)
Projectmanagement
Quality standards
Planification
Configurationmanagement
Analysis, design, code validation
iteration 1
Analysis, design, code validation
Analysis, design, code validation
Analysis, design, code validation
Analysis, design, code validation
Documentationmanagement
iteration n
Quality manual
iteration n
Qualitymanagement
deployment
Riskmanagement
Recollection
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The reuse process
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Organization , hierarchical
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Matrix organization
Program management
Knowledge centers
Reuse center
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Agenda

• The software process
• Quality attributes
• The actors of quality
• Software components
• Components versus objects
• Component reuse
• Architecture
• product architecture
• software architecture

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Product architecture

• Hardware/networkChoice

• monostation

• client server

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Product architecture

• Hardware/networkChoice

• monostation

• client server

• 3 tiers, multi tiers, n tiers

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Software architecture
Software product
Business components
Middleware components
Technical components
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Software architecture facts

• Art (research)
• design explicit architecture
• components and connectors

• Business (industry)
• old economy , critical
• described explicitly but often not actualized
• old economy , corporate
• thought of but often not described explicitly
• RAD often not thought of
• new economy
• not thought of
• no explicit first class connectors
• ad hoc solutions for run time binding)

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Software architecture facts

• Art (research)
• Architecture Design language to describe
  architecture and generate applications

• Business (industry)
• programming (C) and script (make) to describe
  configuration of applications

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Software product line

• Product line architecture
• product line working space
• Set of reusable components
• set of products
• architecture derived from PLA
• instantiated and configured components
• product specific code
• product working space

PLSA
components
P1
P2
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Converting to reuse

• Variability vs. commonality
• domain analysis
• products requirements
• stick to expected and required variability

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Conclusion Thumb rules

• Foresee in the long term
• Adapt architecture incrementally
• Work on actual fact
• take into account the cultural aspect
• Train people
• Measure progress to encourage

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Thank you for attention

• hugues_at_essi.fr