UNIT- 4
Information engineering
A methodology for developing an integrated information system based on the
sharing of common data, with emphasis on decision support needs as well as
transaction-processing (TP) requirements. It assumes logical data representations are
relatively stable, as opposed to the frequently changing processes that use the data.
Therefore, the logical data model, which reflects an organization’s rules and policies,
should be the basis for systems development.
Structured system analysis and design
Structured systems analysis and design methodology (SSADM) is a set of standards
for systems analysis and application design. It uses a formal methodical approach to
the analysis and design of information systems. The SSADM is an open
methodology based on the waterfall model. It has been used by many commercial
businesses, consultants, educational establishments and CASE tool developers. One
of the main features of SSADM is the intensive user involvement in the requirements
analysis stage.
The techniques used in SSADM are logical data modeling, data flow modeling and
entity behavior modeling.
• Logical Data Modeling: This involves the process of identifying, modeling
and documenting data as a part of system requirements gathering. The data
are classified further into entities and relationships.
• Data Flow Modeling: This involves tracking the data flow in an information
system. It clearly analyzes the processes, data stores, external entities and data
movement.
• Entity Behavior Modeling: This involves identifying and documenting the
events influencing each entity and the sequence in which these events happen.
Some of the important characteristics of SSADM are:
• Dividing a project into small modules with well defined objectives
• Useful during requirements specification and system design stage
• Diagrammatic representation and other useful modeling techniques
• Simple and easily understood by clients and developers
• Performing activities in a sequence
The stages of SSADM include:
, • Determining feasibility
• Investigating the current environment
• Determining business systems options
• Defining requirements
• Determining technical system options
• Creating the logical design
• Creating the physical design
Object Oriented Methodology
• It is a new system development approach, encouraging and facilitating re-use of
software components.
• It employs international standard Unified Modeling Language (UML) from the
Object Management Group (OMG).
• Using this methodology, a system can be developed on a component basis, which
enables the effective re-use of existing components; it facilitates the sharing of its
other system components.
• Object Oriented Methodology asks the analyst to determine what the objects of
the system are? What responsibilities and relationships an object has to do with
the other objects? And how they behave over time?
There are three types of Object Oriented Methodologies
1. Object Modeling Techniques (OMT)
2. Object Process Methodology (OPM)
3. Rational Unified Process (RUP)
1. Object Modeling Techniques (OMT)
• It was one of the first object oriented methodologies and was introduced by
Rumbaugh in 1991.
• OMT uses three different models that are combined in a way that is analogous to
the older structured methodologies.
Information engineering
A methodology for developing an integrated information system based on the
sharing of common data, with emphasis on decision support needs as well as
transaction-processing (TP) requirements. It assumes logical data representations are
relatively stable, as opposed to the frequently changing processes that use the data.
Therefore, the logical data model, which reflects an organization’s rules and policies,
should be the basis for systems development.
Structured system analysis and design
Structured systems analysis and design methodology (SSADM) is a set of standards
for systems analysis and application design. It uses a formal methodical approach to
the analysis and design of information systems. The SSADM is an open
methodology based on the waterfall model. It has been used by many commercial
businesses, consultants, educational establishments and CASE tool developers. One
of the main features of SSADM is the intensive user involvement in the requirements
analysis stage.
The techniques used in SSADM are logical data modeling, data flow modeling and
entity behavior modeling.
• Logical Data Modeling: This involves the process of identifying, modeling
and documenting data as a part of system requirements gathering. The data
are classified further into entities and relationships.
• Data Flow Modeling: This involves tracking the data flow in an information
system. It clearly analyzes the processes, data stores, external entities and data
movement.
• Entity Behavior Modeling: This involves identifying and documenting the
events influencing each entity and the sequence in which these events happen.
Some of the important characteristics of SSADM are:
• Dividing a project into small modules with well defined objectives
• Useful during requirements specification and system design stage
• Diagrammatic representation and other useful modeling techniques
• Simple and easily understood by clients and developers
• Performing activities in a sequence
The stages of SSADM include:
, • Determining feasibility
• Investigating the current environment
• Determining business systems options
• Defining requirements
• Determining technical system options
• Creating the logical design
• Creating the physical design
Object Oriented Methodology
• It is a new system development approach, encouraging and facilitating re-use of
software components.
• It employs international standard Unified Modeling Language (UML) from the
Object Management Group (OMG).
• Using this methodology, a system can be developed on a component basis, which
enables the effective re-use of existing components; it facilitates the sharing of its
other system components.
• Object Oriented Methodology asks the analyst to determine what the objects of
the system are? What responsibilities and relationships an object has to do with
the other objects? And how they behave over time?
There are three types of Object Oriented Methodologies
1. Object Modeling Techniques (OMT)
2. Object Process Methodology (OPM)
3. Rational Unified Process (RUP)
1. Object Modeling Techniques (OMT)
• It was one of the first object oriented methodologies and was introduced by
Rumbaugh in 1991.
• OMT uses three different models that are combined in a way that is analogous to
the older structured methodologies.
