A Technical Seminar Report on Topic

SOFTWARE DEVELOPMENT LIFE CYCLE MODEL

Submitted to Babu Banarasi Das University

For the partial fulfilment of the award of the degree of

Bachelor of Honors
In

Computer Science

By

Suraj Kumar Chauhan

B.Sc.(Hons.) Computer Science 5th Semester
(University Roll No.: 1211099044)
Under the Guidance of

Dr. Gaurav Kant Shankhdhar

Assistant Professor Department of Mathematics and Computer Science School of
Basic Sciences, Babu Banarasi Das University, Lucknow.

Department of Mathematics and Computer Science

School of Basic Sciences, Babu Banarasi Das University

Lucknow 226028(U.P.),India
2024
 Software Development Life Cycle (SDLC)

The SDLC aims to produce a high-quality software that meets or exceeds

customer expectations, reaches completion within times and cost
estimates. 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. Software Development Life Cycle (SDLC)
is a process used by the software industry to design, develop and test high
quality software.

Stages of a typical SDLC

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.
• Planning for the quality assurance requirements and identification of the
risks associated with the project is also done in the planning stage. The
outcome of the technical feasibility study is to define the various technical
approaches that can be followed to implement the project successfully with
minimum risks.

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 Product Architecture

• 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.

• This DDS is reviewed by all the important stakeholders and based on

various parameters as risk assessment, product robustness, design
modularity, budget and time constraints, the best design approach is
selected for the product.

• 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 (if any). The internal design of all the
 modules of the proposed architecture should be clearly defined with the
minutest of the details in DDS.

Stage 4: Building or Developing the Product

• 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.

• Developers must follow the coding guidelines defined by their organization

and programming tools like compilers, interpreters, debuggers, etc. are used
to generate the code. 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.

Stage 6: Deployment in the Market and Maintenance

• Once the product is tested and ready to be deployed it is released formally

in the appropriate market. Sometimes product deployment happens in
stages as per the business strategy of that organization. The product may
first be released in a limited segment and tested in the real business
environment (UAT- User acceptance testing).
• Then based on the feedback, the product may be released as it is or with
suggested enhancements in the targeting market segment. After the product
is released in the market, its maintenance is done for the existing customer
base.
 Software Development Life Cycle Models

• Waterfall Model (For sample, Only this model is explained in detail)

• Iterative Model
• Evolutionary Model
• Prototype Model
• Spiral Model
• RAD Model
• Agile Model
• Incremental Model

Waterfall Model

• The Waterfall Model was the first Process Model to be introduced. It is also
referred to as a linear-sequential life cycle model. It is very simple to
understand and use. In a waterfall model, each phase must be completed
before the next phase can begin and there is no overlapping in the phases.

• The Waterfall model is the earliest SDLC approach that was used for
software development.
• The waterfall Model illustrates the software development process in a linear
sequential flow. This means that any phase in the development process
begins only if the previous phase is complete. In this waterfall model, the
phases do not overlap.

• Waterfall approach was first SDLC Model to be used widely in Software

Engineering to ensure success of the project.

• In "The Waterfall" approach, the whole process of software development is

divided into separate phases.
• In this Waterfall model, typically, the outcome of one phase acts as the input
for the next phase sequentially.

Sequential phases in Waterfall model

• Requirement Gathering and analysis − All possible requirements of the

system to be developed are captured in this phase and documented in a
requirement specification document.

• System Design − The requirement specifications from first phase are

studied in this phase and the system design is prepared. This system
design helps in specifying hardware and system requirements and helps in
defining the overall system architecture.
 • Implementation − With inputs from the system design, the system is first
developed in small programs called units, which are integrated in the next
phase. Each unit is developed and tested for its functionality, which is
referred to as Unit Testing.

Sequential phases in Waterfall model

• Integration and Testing − All the units developed in the implementation

phase are integrated into a system after testing of each unit. Post integration
the entire system is tested for any faults and failures.

• Deployment of system − Once the functional and non-functional testing is

done; the product is deployed in the customer environment or released into
the market.

• Maintenance − There are some issues which come up in the client

environment. To fix those issues, patches are released. Also to enhance the
product some better versions are released. Maintenance is done to deliver
these changes in the customer environment.

Waterfall Model - Application

Every software developed is different and requires a suitable SDLC approach to

be followed based on the internal and external factors.

Some situations where the use of Waterfall model is most appropriate are −

• Requirements are very well documented, clear and fixed.

• Product definition is stable.
• Technology is understood and is not dynamic.
• There are no ambiguous requirements.
• Ample resources with required expertise are available to support the
product.
• The project is short.

Waterfall Model - Advantages

• The advantages of waterfall development are that it allows for

departmentalization and control.
• A schedule can be set with deadlines for each stage of development and a
product can proceed through the development process model phases one by
one.
• Development moves from concept, through design, implementation,
testing, installation, troubleshooting, and ends up at operation and
maintenance.
• Each phase of development proceeds in strict order.

• Simple and easy to understand and use.

• Easy to manage due to the rigidity of the model. Each phase has specific
deliverables and a review process.
• Phases are processed and completed one at a time.
• Works well for smaller projects where requirements are very well
understood.
• Clearly defined stages.
• Well understood milestones.
• Easy to arrange tasks.
• Process and results are well documented.

Waterfall Model - Disadvantages

• The disadvantage of waterfall development is that it does not allow much

reflection or revision.
• Once an application is in the testing stage, it is very difficult to go back and
change something that was not well-documented or thought upon in the
concept stage.
• No working software is produced until late during the life cycle.
• High amounts of risk and uncertainty.
• Not a good model for complex and object-oriented projects.
• Poor model for long and ongoing projects.
• Not suitable for the projects where requirements are at a moderate to high
risk of changing. So, risk and uncertainty is high with this process model.
• It is difficult to measure progress within stages.
• Cannot accommodate changing requirements.
• Adjusting scope during the life cycle can end a project.
• Integration is done as a "big-bang. at the very end, which doesn't allow
identifying any technologies or business bottleneck or challenges early.

Summary

• There are many existing models for developing systems for different sizes
of projects and requirements.
• Waterfall model and spiral model are used commonly in developing
systems.
• Each model has advantages and disadvantages for the development of
systems , so each model tries to eliminate the disadvantages of the previous
model.

Final Conclusion

• The structure imposed by the SDLC is specifically designed to maximize

the probability of a successful software development effort.
• It is critical for the project manager to establish and monitor control
objectives during each SDLC phase while executing projects.
• On the basis of the features for a particular software project one can decide
which of these software development life cycle models should be chosen
for that particular project.
• Selecting the correct life cycle model is extremely important in a software
industry as the software has to be delivered within the time deadline and
should also have the desired quality.