UNIT -1
Overview of System Analysis and Design: Systems Development Life Cycle
System: The word System is derived from Greek word “Systema”, which means
an organized relationship between any set of components to achieve some
common cause or objective. A system is “an orderly grouping of interdependent
components linked together according to a plan to achieve a specific goal.”
Information: It’s a collection of raw material. It’s collection of data.
Characteristics of a system:
Organization:
It implies structure and order. It is the arrangement of components that helps
to achieve objectives.
Interaction:
It refers to the manner in which each component functions with other
components of the system.
Interdependence:
It means that parts of the organization or computer system depend on one
another. They are coordinated and linked together according to a plan. One
subsystem depends on the output of another subsystem for proper
functioning.
Integration: It refers to the holism of systems. It is concerned with how a
system is tied together.
Central Objective:
A system should have a central objective. Objectives may be real or stated.
Although a stated objective may be the real objective, it is not uncommon
for an organization to state one objective and operates to achieve another.
Software or System Development Life Cycle (SDLC)
System Development Life Cycle (SDLC) is a conceptual model which includes
policies and procedures for developing or altering systems throughout their life
cycles. The SDLC aims to produce high-quality software that meets or exceeds
customer expectations, reaches completion within times and cost estimates. It is
also called as Software Development Process. SDLC is a framework defining
tasks performed at each step in the software development process.
, SDLC is a process followed for a software project, within a software organization.
It consists of a detailed plan describing how to develop, maintain, replace and
alter or enhance specific software. The life cycle defines a methodology for
improving the quality of software and the overall development process.
Need of SDLC
The development team must determine a suitable life cycle model for a particular plan
and then observe to it. Without using an exact life cycle model, the development of a
software product would not be in a systematic and disciplined manner. When a team is
developing a software product, there must be a clear understanding among team
representative about when and what to do. Otherwise, it would point to chaos and
project failure
Typical Software Development Life Cycle consists of the following stages −
Stage 1: Planning and Requirement Analysis
Requirement analysis is the most important and fundamental stage in SDLC. It is
performed by the senior members of the team with inputs from the customer, the
sales department, market surveys and domain experts in the industry. This
, information is then used to plan the basic project approach and to conduct product
feasibility study in the economical, operational and technical areas.
Stage 2: Defining Requirements
Once the requirement analysis is done the next step is to clearly define and
document the product requirements and get them approved from the customer or
the market analysts. This is done through an SRS (Software Requirement
Specification) document which consists of all the product requirements to be
designed and developed during the project life cycle
Stage 3: Designing the Software
SRS is the reference for product architects to come out with the best architecture
for the product to be developed. Based on the requirements specified in SRS,
usually more than one design approach for the product architecture is proposed
and documented in a DDS - Design Document Specification.
A design approach clearly defines all the architectural modules of the product
along with its communication and data flow representation with the external and
third party modules
Stage 4: Developing the project
In this stage of SDLC the actual development starts and the product is built. The
programming code is generated as per DDS during this stage. If the design is
performed in a detailed and organized manner, code generation can be
accomplished without much hassle. Different high level programming languages
such as C, C++, Pascal, Java and PHP are used for coding. The programming
language is chosen with respect to the type of software being developed.
Stage 5: Testing the Product
This stage is usually a subset of all the stages as in the modern SDLC models, the
testing activities are mostly involved in all the stages of SDLC. However, this
stage refers to the testing only stage of the product where product defects are
reported, tracked, fixed and retested, until the product reaches the quality
standards defined in the SRS.
Stage6: Deployment
Once the software is certified, and no bugs or errors are stated, then it is deployed.
Then based on the assessment, the software may be released as it is or with
suggested enhancement in the object segment. After the software is deployed, then
its maintenance begins.
Stage7: Maintenance
Overview of System Analysis and Design: Systems Development Life Cycle
System: The word System is derived from Greek word “Systema”, which means
an organized relationship between any set of components to achieve some
common cause or objective. A system is “an orderly grouping of interdependent
components linked together according to a plan to achieve a specific goal.”
Information: It’s a collection of raw material. It’s collection of data.
Characteristics of a system:
Organization:
It implies structure and order. It is the arrangement of components that helps
to achieve objectives.
Interaction:
It refers to the manner in which each component functions with other
components of the system.
Interdependence:
It means that parts of the organization or computer system depend on one
another. They are coordinated and linked together according to a plan. One
subsystem depends on the output of another subsystem for proper
functioning.
Integration: It refers to the holism of systems. It is concerned with how a
system is tied together.
Central Objective:
A system should have a central objective. Objectives may be real or stated.
Although a stated objective may be the real objective, it is not uncommon
for an organization to state one objective and operates to achieve another.
Software or System Development Life Cycle (SDLC)
System Development Life Cycle (SDLC) is a conceptual model which includes
policies and procedures for developing or altering systems throughout their life
cycles. The SDLC aims to produce high-quality software that meets or exceeds
customer expectations, reaches completion within times and cost estimates. It is
also called as Software Development Process. SDLC is a framework defining
tasks performed at each step in the software development process.
, SDLC is a process followed for a software project, within a software organization.
It consists of a detailed plan describing how to develop, maintain, replace and
alter or enhance specific software. The life cycle defines a methodology for
improving the quality of software and the overall development process.
Need of SDLC
The development team must determine a suitable life cycle model for a particular plan
and then observe to it. Without using an exact life cycle model, the development of a
software product would not be in a systematic and disciplined manner. When a team is
developing a software product, there must be a clear understanding among team
representative about when and what to do. Otherwise, it would point to chaos and
project failure
Typical Software Development Life Cycle consists of the following stages −
Stage 1: Planning and Requirement Analysis
Requirement analysis is the most important and fundamental stage in SDLC. It is
performed by the senior members of the team with inputs from the customer, the
sales department, market surveys and domain experts in the industry. This
, information is then used to plan the basic project approach and to conduct product
feasibility study in the economical, operational and technical areas.
Stage 2: Defining Requirements
Once the requirement analysis is done the next step is to clearly define and
document the product requirements and get them approved from the customer or
the market analysts. This is done through an SRS (Software Requirement
Specification) document which consists of all the product requirements to be
designed and developed during the project life cycle
Stage 3: Designing the Software
SRS is the reference for product architects to come out with the best architecture
for the product to be developed. Based on the requirements specified in SRS,
usually more than one design approach for the product architecture is proposed
and documented in a DDS - Design Document Specification.
A design approach clearly defines all the architectural modules of the product
along with its communication and data flow representation with the external and
third party modules
Stage 4: Developing the project
In this stage of SDLC the actual development starts and the product is built. The
programming code is generated as per DDS during this stage. If the design is
performed in a detailed and organized manner, code generation can be
accomplished without much hassle. Different high level programming languages
such as C, C++, Pascal, Java and PHP are used for coding. The programming
language is chosen with respect to the type of software being developed.
Stage 5: Testing the Product
This stage is usually a subset of all the stages as in the modern SDLC models, the
testing activities are mostly involved in all the stages of SDLC. However, this
stage refers to the testing only stage of the product where product defects are
reported, tracked, fixed and retested, until the product reaches the quality
standards defined in the SRS.
Stage6: Deployment
Once the software is certified, and no bugs or errors are stated, then it is deployed.
Then based on the assessment, the software may be released as it is or with
suggested enhancement in the object segment. After the software is deployed, then
its maintenance begins.
Stage7: Maintenance
