Transcript Software Engineering

CASE Tools
CIS 376
Bruce R. Maxim
UM-Dearborn
1
CASE Tools
• Computer-Aided Software Engineering
• Prerequisites to tool use
– Need a collection of useful tools that help
in every step of building a product
– Need an organized layout that enables
tools to be found quickly and used
efficiently
– Need a Skilled craftsperson who
understands how to use the tools
effectively
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CASE Tools
• Upper CASE
– requirements
– specification
– planning
– design
• Lower CASE
– implementation
– integration
– maintenance
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CASE Building Blocks - 1
• CASE tools
• Integration framework
– specialized programs allowing CASE tools
to communicate with one another
• Portability services
– allow CASE tools and their integration
framework to migrate across different
operating systems and hardware platforms
without significant adaptive maintenance
4
CASE Building Blocks - 2
• Operating system
– database and object management services
• Hardware platform
• Environmental architecture
– hardware and system support
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A Taxonomy of CASE Tools
business systems planning
project management
support
CASE
Database
analysis and design
programming
integration &testing
prototyping/simulation tools
re–engineering
framework
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CASE Tool Taxonomy - 1
• Business process engineering tools
– represent business data objects, their
relationships, and flow of the data objects between
company business areas
• Process modeling and management tools
– represent key elements of processes and provide
links to other tools that provide support to defined
process activities
• Project planning tools
– used for cost and effort estimation, and project
scheduling
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CASE Tool Taxonomy - 2
• Risk analysis tools
– help project managers build risk tables by
providing detailed guidance in the
identification and analysis of risks
• Requirements tracing tools
– provide systematic database-like approach
to tracking requirement status beginning
with specification
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CASE Tool Taxonomy - 3
• Metrics and management tools
– management oriented tools capture project
specific metrics that provide an overall indication
of productivity or quality, technically oriented
metrics determine metrics that provide greater
insight into the quality of design or code
• Documentation tools
– provide opportunities for improved productivity by
reducing the amount of time needed to produce
work products
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CASE Tool Taxonomy - 4
• System software tools
– network system software, object management
services, distributed component support, and
communications software
• Quality assurance tools
– metrics tools that audit source code to determine
compliance with language standards or tools that
extract metrics to project the quality of software
being built
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CASE Tool Taxonomy - 5
• Database management tools
– RDMS and OODMS serve as the foundation for
the establishment of the CASE repository
• Software configuration management tools
– uses the CASE repository to assist with all SCM
tasks (identification, version control, change
control, auditing, status accounting)
• Analysis and design tools
– enable the software engineer to create analysis
and design models of the system to be built,
perform consistency checking between models
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CASE Tool Taxonomy - 6
• PRO/SIM tools
– prototyping and simulation tools provide software
engineers with ability to predict the behavior of
real-time systems before they are built and the
creation of interface mockups for customer review
• Interface design and development tools
– toolkits of interface components, often part
environment with a GUI to allow rapid prototyping
of user interface designs
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CASE Tool Taxonomy - 7
• Prototyping tools
– enable rapid definition of screen layouts, data
design, and report generation
• Programming tools
– compilers, editors, debuggers, OO programming
environments, fourth generation languages,
graphical programming environments, applications
generators, and database query generators
• Web development tools
– assist with the generation of web page text,
graphics, forms, scripts, applets, etc.
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CASE Tool Taxonomy - 8
• Integration and testing tools
– Data acquisition
• get data for testing
– static measurement
• analyze source code without using test cases
– dynamic measurement
• analyze source code during execution
– Simulation
• simulate function of hardware and other externals)
– test management
– cross-functional tools
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CASE Tool Taxonomy - 9
• Static analysis tools
– code-based testing tools, specialized testing
languages, requirements-based testing tools
• Dynamic analysis tools
– intrusive tools modify source code by inserting
probes to check path coverage, assertions, or
execution flow, non-intrusive tools use a separate
hardware processor running in parallel with
processor containing the program being tested
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CASE Tool Taxonomy - 10
• Test management tools
– coordinate regression testing, compare
actual and expected output, conduct batch
testing, and serve as generic test drivers
• Client/server testing tools
– exercise the GUI and network
communications requirements for the client
and server
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CASE Tool Taxonomy - 11
• Reengineering tools
– reverse engineering to specification tools
• generate analysis and design models from
source code, where used lists, and other
design information
– code restructuring and analysis tools
• analyze program syntax, generate control flow
graph, and automatically generates a
structured program
– on-line system reengineering tools
• used to modify on-line DBMS
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The next 17 slides come from
Sommerville’s book
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Requirements validation
• Concerned with demonstrating that the
requirements define the system that the
customer really wants
• Requirements error costs are high so
validation is very important
– Fixing a requirements error after delivery
may cost up to 100 times the cost of fixing
an implementation error
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Requirements validation
techniques
• Requirements reviews
– Systematic manual analysis of the requirements
• Prototyping
– Using an executable model of the system to check
requirements.
• Test-case generation
– Developing tests for requirements to check
testability
• Automated consistency analysis
– Checking the consistency of a structured
requirements description
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Automated consistency
checking
Requirements
in a formal language
Requirements
problem report
Requirements
processor
Requirements
analyser
Requir ements
database
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Requirements management
• Requirements management is the process of
managing changing requirements during the
requirements engineering process and
system development
• Requirements are inevitably incomplete and
inconsistent
– New requirements emerge during the process as
business needs change and a better
understanding of the system is developed
– Different viewpoints have different requirements
and these are often contradictory
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Requirements Change
• The priority of requirements from different
viewpoints changes during the development
process
• System customers may specify requirements
from a business perspective that conflict with
end-user requirements
• The business and technical environment of
the system changes during its development
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Requirements evolution
Initial
understanding
of problem
Initial
requirements
Changed
understanding
of problem
Changed
requir ements
Time
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Requirements Management
Planning
• During the requirements engineering process,
you have to plan:
– Requirements identification
• How requirements are individually identified
– A change management process
• The process followed when analysing a requirements
change
– Traceability policies
• The amount of information about requirements
relationships that is maintained
– CASE tool support
• The tool support required to help manage requirements
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change
Traceability
• Traceability is concerned with the
relationships between requirements, their
sources and the system design
• Source traceability
– Links from requirements to stakeholders who
proposed these requirements
• Requirements traceability
– Links between dependent requirements
• Design traceability
– Links from the requirements to the design
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CASE tool support
• Requirements storage
– Requirements should be managed in a secure,
managed data store
• Change management
– The process of change management is a workflow
process whose stages can be defined and
information flow between these stages partially
automated
• Traceability management
– Automated retrieval of the links between
requirements
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Requirements Change
Management
• Should apply to all proposed changes to the
requirements
• Principal stages
– Problem analysis. Discuss requirements problem
and propose change
– Change analysis and costing. Assess effects of
change on other requirements
– Change implementation. Modify requirements
document and other documents to reflect change
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CASE Workbenches
• A coherent set of tools that is designed to
support related software process activities
such as analysis, design or testing
• Analysis and design workbenches support
system modelling during both requirements
engineering and system design
• These workbenches may support a specific
design method or may provide support for a
creating several different types of system
models
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An analysis and design
workbench
Data
dictionary
Structured
diagramming
tools
Report
generation
facilities
Code
generator
Central
information
repository
Query
language
facilities
Forms
creation
tools
Design, analysis
and checking
tools
Import/export
facilities
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Analysis workbench
components
•
•
•
•
•
•
•
•
Diagram editors
Model analysis and checking tools
Repository and associated query language
Data dictionary
Report definition and generation tools
Forms definition tools
Import/export translators
Code generation tools
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Testing Workbenches
• Testing is an expensive process phase.
• Testing workbenches provide a range of tools
to reduce the time required and total testing
costs
• Most testing workbenches are open systems
because testing needs are organizationspecific
• Difficult to integrate testing with closed design
and analysis workbenches
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Testing Workbench
Test data
generator
Specification
Source
code
Test
manager
Test data
Oracle
Dynamic
analyser
Program
being tested
Test
results
Test
predictions
Execution
report
Simulator
File
comparator
Report
generator
Test results
report
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Testing Workbench Adaptation
• Scripts may be developed for user
interface simulators and patterns for test
data generators
• Test outputs may have to be prepared
manually for comparison
• Special-purpose file comparators may
be developed
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Integrated CASE Environments -1
• Provide mechanism for sharing information among all
tools contained in the environment
• Enable changes to items to be tracked to other
information items
• Provide version control and overall configuration
management
• Allow direct access to any tool contained in the
environment
• Establish automated support for the chosen software
process model, integrating CASE tools and SCI's into
a standard work break down structure
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Integrated CASE Environments -2
• Establish automated support for the chosen software
process model, integrating CASE tools and SCI's into
a standard work break down structure
• Enable users of each tool to experience a consistent
look and feel at the human-computer interface
• Support communication among software engineers
• Collect both management and technical metrics to
improve the process and the product
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The Challenge: Putting it Together
Operating
System
Portability
Services
Integration
Framework
IPSE
CASE
Tools
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An Integration Framework
user interface layer
interface tool kit
presentation protocol
tools management services
CASE
tool
tools layer
object management layer
integration services
configuration management services
shared repository layer
CASE database
access control functions
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Integration Architecture - 1
• User Interface Layer
– interface toolkit
• contains software for UI management and library of
display objects
– common presentation protocol
• guidelines that give all CASE tools the same look and
feel (icons, mouse behavior, menu names, object names)
• Tools Layer
– tools management services
• control behavior of tools inside environment
– CASE tools themselves
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Integration Architecture - 2
• Object management layer (OML)
– performs the configuration management
function, working with the CASE repository
OML provides integration services
• Shared repository layer
– CASE database and access control
functions enabling the OML to interact with
the database
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CASE Repository Functions - 1
• Data integrity
– includes functions to validate entries to the
repository and ensure consistency among related
objects
• Information sharing
– provides mechanism for sharing information
among multiple developers and multiple tools,
controls modification of information
• Data-tool integration
– establishes shared data model and performs
configuration management functions
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CASE Repository Functions - 2
• Data-data integration
– database management system allowing access to
related objects so functions can be achieved
• Methodology enforcement
– E-R model used to define steps needed to be
conducted to build the repository contents
• Document standardization
– definition of objects in the database leads directly
to a standard approach for creation of engineering
documents
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Data Integration:
The CASE Repository
CASE Database
Shared Repository Layer
database
access control functions
Objects
Object Management Layer
integration services
SCM services
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CASE Repository Content Summary
•
•
•
•
Problem to be solved.
Problem domain.
Emerging solution.
Rules pertaining to software process
methodology.
• Project plan.
• Organizational content.
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DBMS Features Needed for
CASE Repositories
•
•
•
•
•
•
•
Non-redundant data storage
High-level access
Data independence
Transaction control
Ad hoc data queries and reports
Openness
Multi-user support
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CASE Repository Features - 1
• Storage of sophisticated data structures
– diagrams
– documents
– files
– simple variables
– information model describing relationships
and semantics of data stored in repository
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CASE Repository Features - 2
• Integrity enforcement
– business rules
– policies, constraints
– requirements on the information being
entered into repository, triggers may be
used to check the validity of the design
models in real time
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CASE Repository Features - 3
• Semantic-rich tool interface
– repository meta-model contains semantics that
enable a variety of tools to interpret meaning of
data stored in the repository
• Process/project management
– contains information about the software
application
– characteristics of each project
– organization's general process for software
development - phases, tasks, deliverables
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Configuration Management
Features Need by CASE Tools
• Versioning
• Dependency tracking and change
management
• Requirements tracing
• Configuration management
• Audit trails
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The next 3 slides come from
Sommerville’s book
50
CASE tools for
Configuration Management
• Configuration management processes are
standardized and involve applying predefined procedures
• Large amounts of data must be managed
• CASE tool support for configuration
management is essential
• Mature CASE tools to support configuration
management are available ranging from
stand-alone tools to integrated workbenches
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Change Management Tools
• Change management is a procedural process
so it can be modelled and integrated with a
version management system
• Change management tools
– Form editor to support processing the change
request forms
– Workflow system to define who does what and to
automate information transfer
– Change database that manages change proposals
and is linked to a VM system
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Version Management Tools
• Version and release identification
– Systems assign identifiers automatically when a
new version is submitted to the system
• Storage management.
– System stores the differences between versions
rather than all the version code
• Change history recording
– Record reasons for version creation
• Independent development
– Only one version at a time may be checked out for
change. Parallel working on different versions
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