technical module e - case-tools

CASE/Tools

Technical Module E

Computer-Aided Software Engineering

Computer-aided software engineering is a philosophy for using the computer to model a firm, its activities, and its development of information systems. CASE originated in 1980Offshoot of Computer Aided Design (CAD)

RepositoryA repository is an electronic storage of all of the system documentation such as

Data elementsData structuresData flowsProcess logicObject classes

It is also called central encyclopedia

CASE Repository

CASE Fundamentals

The CASE Documentation

Fig E.2: Some System Documentation Prepared by CASE

Categories of CASE/Tools

Client ServerWeb-based Personal Computers

Categories of CASE ToolsUpper CASE Tools

During strategic planning for information resources, enterprise modeling

Middle CASE ToolsIs one that is used during the analysis and design stages to document the existing and new systems.

Lower CASE ToolsIs used during the construction and installation stages

Integrated CASE ToolsCombination of all the above

Middle CASE/Tools

Data ModelsProcess Models

Object Models

Integrated CASE/ToolsSupport phased system developmentProvide project management capabilityProject Characteristics

They are unique within an organization and have defined start and end points.They have a work scope that can be decomposed into definite tasksThey have a budgetThey require the use of resourcesThey often cross organizational boundaries

CASE Documentation Examples

A data modelFig E.3: A Data Architect Entity-Relationship Diagram

CASE Documentation Examples

A process modelFig E.4: A COOL: Gen Dependency Diagram

CASE Documentation Examples

Another process modelFig E.5: A COOL: Gen Hierarchy Chart

CASE Documentation Examples

And another process modelFig E.6: A COOL: Gen Action Diagram

CASE Documentation Examples

An object modelFig E.7: A Rational Rose Class Diagram

CASE Documentation Examples

Another object modelFig E.8: A Rational Rose Sequence Diagram

CASE Documentation Examples

And another object modelFig E.9: A Rational Rose Statechart Diagram

Using CASE for Project Management

Budgeting Forecasting, analysis, corrective actionsWork breakdown structureGantt charts and network diagramsPerformance tracking graphics

How CASE affects the SDLCCan lengthen early phasesCan reduce the time required for coding, testing, and user educationShould drastically reduce maintenance time and costConsistency checking detects errors earlier in the SDLC, when they are easiest and least expensive to correct.

Consistency Checking

Consistency checking ensures that the diagrams and data repository entries are complete, do not violate any methodological rules, and are consistent within and among diagrams.

Consistency checking can detect

Unnamed or unnumbered modulesDangling modulesIncorrectly placed control structuresLack of balanceLack of appropriate keys on data structuresLack of data normalizationLack of data repository entry for a data store that appears on a DFD or vice versa.

Evolving support of CASE

Modeling tools – from ERDs and DFDs to object diagramsHardware platforms – from mainframes to client/server to Web-based systems