Importance of Software Development Lifecycles

The report provides an overview of various software development models, including their advantages and disadvantages. It highlights the significance of a feasibility study in ensuring that a project is feasible and meets the requirements. The report aims to provide students with a comprehensive understanding of software development lifecycles and the importance of a feasibility study.

ASSIGNMENT 1 FRONT SHEET
Qualification BTEC Level 5 HND Diploma in Computing
Unit number and
title Unit 9: Software Development Life Cycle
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submission
Re-submission
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consequences of plagiarism. I understand that making a false declaration is a form of malpractice.
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Contents
A. Introduce............................................................................................................................... 6
B. Content.................................................................................................................................. 6
I Describe different software development lifecycles...........................................................6
1. Software development life cycle (SDLC)......................................................................6
2. Models in SDLC............................................................................................................8
II Explain how risk is managed in the Spiral lifecycle model................................................17
III Explain the purpose of a feasibility report........................................................................18
IV Discuss the components of a feasibility report.................................................................19
1. Technical feasibility................................................................................................... 19
2. Operational feasibility................................................................................................20
3. Economic feasibility...................................................................................................20
4. Legal feasibility.......................................................................................................... 20
5. Schedule feasibility....................................................................................................20
V Technical solutions that Tune Source can choose to develop the system........................21
C. CONCLUSION....................................................................................................................... 23
D. REFERENCES.........................................................................................................................24
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List of figure
Figure 1. Stages of SDLC.................................................................................................................7
Figure 2. Stages of Waterfall Model..............................................................................................9
Figure 3. Spiral model.................................................................................................................. 11
Figure 4. Stages of V-Model.........................................................................................................13
Figure 5. RAD model.................................................................................................................... 15
Figure 6. Risk Management Process............................................................................................18
Figure 7. Front end...................................................................................................................... 21
Figure 8. Back end........................................................................................................................22
List of table
Table 1. Advantages and disadvantages of Waterfall model.......................................................10
Table 2. Advantages and disadvantages of Spiral model.............................................................12
Table 3. Advantages and disadvantages of V-model....................................................................14
Table 4. Advantages and disadvantages of RAD model...............................................................16
Table 5. Comparison between development models..................................................................17
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A.Introduce
One of the necessary knowledge of a professional software engineer is to know and understand
SDLC (Software Development Life-cycle). System development life cycle models are employed
for the development of various system and inventory management system also follows the
same development life cycle. So, in this report, I will describe different software development
lifecycles and explain the importance of a feasibility study.
B. Content
I Describe different software development lifecycles
1. Software development life cycle (SDLC)
To know more about SDLC, be sure to understand the definition of Software Development
Lifecycle. SDLC is the process of identifying an information system that how to support all the
business needs, system design, development and facilitation to provide users with the
necessary things. The system development lifecycle concept applies to a range of hardware and
software configuration, as a system can be composed of hardware only, software only, or a
combination of both.
SDLC is a term used in systems engineering, information systems and software engineering to
describe a process for planning, creating, testing, and deploying an information system.
A software development life cycle is composed of a number of clearly defined and distinct work
phases which are used by system engineering. Each phase is itself composed of a series of
steps, which rely on techniques that produce deliverables.
In many ways, building an information system is similar to building a house. There are usually
six stages in this cycle:
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Figure 1. Stages of SDLC
a) Planning:
“Why build this system?”, “How to structure project?” Begin with planning, propose alternative
solutions, describe costs and benefits, and submit a preliminary plan with recommendations.
We have to discover the objectives and the nature and scope of the problem. Then we have to
focused on how the problem being studied and fits in with them. After digging into the
organization’s objectives and specific problems, several solutions may have been discovered. In
other words, during this SDLC phase, should determine the feasibility of the project and how
they can implement the project successfully with the lowest risk in mind.
b) System analysis:
“Who, what where, and when for this system?” In the analysis phase, the systems analyst
works extensively with the business users of the new system to understand their needs from
the new system. All the requirements as discussed from end users are gathered and system /
software requirement specification document is formed.
c) System Design:
“How will this system work?” This is the step where desired features and operations are
described in detail, including screen layouts, business rules, process diagrams pseudo code, and
other documentation.
d) Implementation:
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“Let’s create what we want.”
After the designation of system, the real code is written. This is the major and longest step in
project development. The actual coding starts in this phase, as per the requirements and design
phase. System is first developed in small programs called units. System is created, tested,
installed and rolled out with training program.
e) Integration and Testing:
“Did we get what we want?”
After the coding gets completed, software is tested for any discrepancies. This phase goes
through numerous steps like black box (functional + non-functional) testing and white box
testing etc.
f) Maintenance:
“Let’s get this closer to what we want.”
This is the last and final phase which can extend depending upon the project requirement. The
plan almost never turns out perfect when it meets reality. Furthermore, as real-world
conditions change, we need to update and improve our software to match.
2. Models in SDLC
There is a wide range of different SDLC models that help in different types of software
development projects, even in cases where customers do not have a clear vision of what they
need. I am going to explain the following models:
2.1 Waterfall
a) Original Waterfall model
This is linear sequential life cycle model in which each phase must be completed before the
next phase begins. One of the basic prerequisites of the Waterfall model is to get approval at
each stage before the group can move on to the next stage. This approach can be effective in
risk mitigation in the software development life cycle.
Development is seen as flowing steadily downwards through the phases of requirements
analysis, design, implementation, testing (validation), integration, and maintenance.
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Figure 2. Stages of Waterfall Model
b) Basic principles of Waterfall model
The fundamental principle of waterfall project management is simplicity.
Project is divided into sequential phases, with some overlap and splash back acceptable
between phases; emphasis is on planning, time schedules, target dates, budgets and
implementation of an entire system at one time.
Requirements and delivery products, with detailed specifications, are required from the outset.
All team members need to know their roles and the roles of others in order to fulfill their part
of the process.
Documentation should be thorough and sent to everyone involved in the project.
c) When to use Waterfall model
- The requirements and scope are well understood.
- Ample resources with required expertise are available freely.
- The client has high confidence in the organization.
- The project is short.
- It is good to use this model when the technology is well understood.
d) Advantages and disadvantages of Waterfall model
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Advantages Disadvantages
Easy to understand, easy to use. One of major drawback with this approach is
that once we are in testing phase it is difficult to
go back in previous phase and change some
requirement which was not well understood.
Simple to implement, no time consuming.
It works well for smaller projects where
requirements are very well understood.
Not suitable for the projects where
requirements are at a moderate to high risk of
changing and as well, not good model for
complex and object-oriented projects.
Good for management control (plan, staff, track) Often, the client is not very clear of what he
exactly wants from the software. Any changes
that he mentions in between may cause a lot of
confusion.
Each stage has well defined deliverable or
milestone, so there is no overlapping of phases.
Complete, a working model of the software does
not lie in the hands of the client.
It acts as template into which methods for
analysis, design, code test and maintenance can
be placed
Small changes or errors that arise in the
completed software may cause a lot of
problems.
Table 1. Advantages and disadvantages of Waterfall model
2.2 Spiral model
a) Definition:
The Spiral model is a universal software development life cycle model. This model follows four
phases, marketing planning, risk analysis, engineering and evaluation. Software has to pass
through these phases repeatedly in spirals or iterations. It is a meta-model, a model that can be
used by other models.
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Figure 3. Spiral model
b) Spiral principles
A spiral model has 4 phases described below: Planning, Risk Analysis, Engineering and
Evaluation. At the initial spiral, starting with the planning, requirements are gathered and risk is
considered. Requests are gathered during the planning phase. During the risk analysis phase, a
process is underway to identify the risks and their alternatives. A prototype is created at the
end of the risk analysis. The evaluation phase allows the client to evaluate the project outputs
so far before the project goes to the next spiral Determine Objectives, Alternatives, Constraints.
Focus is on risk assessment and on minimizing project risk by breaking a project into smaller
segments and providing more ease-of-change during the development process, as well as
providing the opportunity to evaluate risks and weigh consideration of project continuation
throughout the life cycle.
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Each cycle involves a progression through the same sequence of steps, for each part of the
product and for each of its levels of elaboration, from an overall concept-of-operation
document down to the coding of each individual program.
c) When to use Spiral model:
- New product line
- When assessing costs and risks is important
- For medium to high risk projects
- Committing to a long-term project is unwise as there can be changes to economic
priorities
- The user is not sure about their needs
- Complex requirement
d) Spiral’s advantages and disadvantages
Advantages Disadvantages
This model focuses on reducing the risks involved
in the project.
Cost and time estimations are also not very easy.
Every time a new prototype is obtained, it is
revaluated again and again by the customer, so
more customer involvement is there.
The risk control demands involvement of the
highly-skilled professionals
Better productivity through reuse capabilities. This model doesn’t work for small projects.
Proper control over cost, time and manpower
requirement for a project work.
This model requires risk identification, its
projection, risk assessment and risk management
which is not an easy task.
Table 2. Advantages and disadvantages of Spiral model
2.3 V-Model
a) Definition
The V-Shaped Model is called verification and validation model and follows sequential steps as
waterfall model but here testing phases are planned parallel to corresponding phases of
development.
Business Requirement Specification -> Acceptance Testing
System requirement specification -> System Testing
High Level Design -> System Integration Testing
Low Level Design -> Component Testing
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Coding -> Unit Testing
Figure 4. Stages of V-Model
b) V-model principles
During the requirements stage, System and Acceptance test cases are defined and
documented.
These test cases are executed during the System Test and Acceptance Phase in the
Development cycle.
In the Architecture stage, the Integration test cases are identified and documented. These test
cases are executed during the Integration test phase in the development cycle.
In the Design stage, unit test cases are defined and documented by the developers. These test
cases are performed by developers during Unit Test phase in development cycle.
c) When to use V-model:
- Small and medium scale projects where requirements are clearly defined and fixed.
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- Sample technical resources are available with the required technical expertise.
d) Advantages and disadvantages of V-model
Advantages Disadvantages
Easy to use, simple to use. The model is very rigid and not flexible and does
not handle iterations or phases.
Preliminary testing activities like test planning
and test designing happens before coding, thus
lot of time and cost are saved as chances of error
become less.
As software is developed in coding phase so if any
modifications are there then requirement and
design specs need to be updated.
It avoids the downward flow of the issues and it
works for small projects where requirements are
easily understood.
It works only for small or medium projects.
Table 3. Advantages and disadvantages of V-model
2.4 Rapid Application Development
a) Definition
The Rapid Application Development Model was first proposed by IBM in 1980’s. The RAD (Rapid
Application Development) model is based on iterative prototyping and development without
specific planning. The process of writing software itself involves the planning needed to develop
a product.
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Figure 5. RAD model
b) When to use RAD model
- Wishing to create a system that could be modularized in a 2-3months period.
- It should be used if multiple designers are available to create the model and the budget
is high enough.
- RAD SDLC model should only be chosen if there are resources with high business
knowledge available and there is a need to produce the system in a short time period (2-
3 months).
c) The advantages of the RAD Model
Advantages Disadvantages
Changing requirements can be accommodated Only system that can be modularized can be
built using RAD
Progress can be measured. Requires highly skilled developers/designers.
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Iteration time can be short with use of powerful
RAD tools
Requires user involvement throughout the life
cycle.
Productivity with fewer people in a short time Suitable for project requiring shorter
development times.
Reduced development time. Management complexity is more.
Increases reusability of components. High dependency on Modelling skills.
Integration from very beginning solves a lot of
integration issues.
It can't be used for smaller projects.
Table 4. Advantages and disadvantages of RAD model
2.5 Which is most suitable for Tune Source and discuss why?
Tune Source is a company headquartered in southern California. It develops by selling digital
music to customer through kiosks in our store and via the Internet using their website. So,
choosing a model to develop software for this company is very suitable. The first thing to be
successful is the company needs to have reasonable working process, good support tools, and
the members need to “look in one direction” from which the success rate of this project is very
high. Here, this project has been able to meet the need to have highly qualified staff who are
able to work together very well. The IT department at Tune Source has become experienced
with Internet technology as it has worked with the ISP to maintain the site. Because Tune
Source is a music application software and development company, it should be; interaction
with customers and need to produce products to meet customer requirements as soon as
possible.
Below is a comparison of several development models:
Model
Features
Waterfall model Spiral model V-model RAD model
Clear
requirement
specifications
Initial level Initial level Initial level Initial level
Speed to
change
Low High Low L ow
Cost Low Expensive Low Very high
Flexibility Rigid Flexible Rigid Flexible
Reliability Good Good Excellent Good
Handle Large-
Project
Not appropriate Appropriate Not appropriate Not appropriate
Detailed
Documentation
Necessary Yes Necessary Limited
Maintenance Least Typical Least Easily maintained
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Risk
involvement
High Medium to high risk High Low
Testing After completion At the end of the
engineering phase
Test activities can
be integrated into
each stage of the
software
development life
cycle
After completion
of coding
Objective High assurance High assurance High assurance Rapid
development
Team size Large team Large team Large team Small team
Time-frame Very long Long Long short
Customer
control over
administrator
Very low Yes Yes Yes
Table 5. Comparison between development models
From the weaknesses, the RAD model is a reasonable model for this company, because, in the
process of implementing this model, it will continuously collect information from customers
and update product launches of the company them until the customer feels that the product is
the best and has met the elements and requirements they need. With the RAD model’s criteria,
“Customers are God”, customers have may types, some customers are technologically savvy,
some do not, some think consistently and some are always changing. The customer of the
project and the development team must work together through the project. One last thing a
company has when choosing this model as its development model is to enable early
identification of technology risks and to respond quickly to changing customer requirements.
Therefore, Tune Source should choose RAD model which is suitable for developing software and
music applications.
II Explain how risk is managed in the Spiral lifecycle model.
An effective risk management process is an important component of a successful IT security
program. The spiral model is a risk-oriented development process for software projects,
wherein the whole development process is guided by the involved risks. It aims at identifying
and evaluating software project risks, and helps in reducing these risks and controlling project
cost in a favor of a better controlled software project.
Many things can cause risks like poor staffing, limited range, poor design and overly optimistic
estimates.
The risk management process can be broken down into two interrelated phases, risk
assessment and risk control. The project team must be aware of potential risks so that
problems can be avoided or controlled well ahead of time. Typically, project teams create a risk
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assessment, or a document that tracks potential risks along with an evaluation of the likelihood
of the risk and its potential impact on the project.
Figure 6. Risk Management Process
In each round of the spiral model, to minimize the risk:
- Determine the goal of the part you are working on.
- Map alternatives for implementation.
- Recognize constraints on these alternatives.
- Use prototyping, analysis, etc. to gain necessary knowledge and reduce risk.
- Plan the next step.
- Finally, perform sequence of coding, testing, and integration.
III Explain the purpose of a feasibility report.
In this project, our major pre-requisite was to automate the system to handle the tasks
conveniently and cost effectively. Feasibility study helped a lot in finding out the financial and
technical requirements of the system.
A feasibility report is a document that assesses potential solutions to a business problem or
opportunity and identifies which of these solutions are viable for further analysis. A feasibility
study examines the feasibility of a proposal, business venture or idea, the main function of this
is to determine whether the project will continue or not. In business, feasibility studies work for
a number of reasons.
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As a part of the System analysis and design, it is essential to develop a feasibility report on the
proposed system. The purpose of the feasibility report is to present project parameters and
identify potential solutions to the identified problem, need or opportunity. After considering
various potential solutions, the project team expanded on each of these potential solutions,
providing sufficient details, including very high cost information, to enable the project leader to
propose all potential solutions need to be analyzed further in the next phase with the approval
body.
The feasibility report considers a given proposition to be able to operate in the long term or
subject to potential financial risk. It is also helpful in identifying potential cash flows. Another
important purpose is that it helps planners stay focused on projects and narrow down
possibilities. Accordingly, a feasibility study could provide the season of not pursuing the
project or proposition. When it comes to operational aspects, the analysis determines whether
the plan has the resources needed to be able to implement it. In addition, you may have
knowledge of trends because a feasibility study looks at today’s market and studies the
expected growth of your target business.
Feasibility studies are common in all industries. Whether a hotel, restaurant, real estate,
medical, office or industrial. Starting a feasibility study will ensure you save time and money for
the project.
A good Tune Source feasibility study will help find the company's financial condition, its
strengths and weaknesses, its market position. It also facilitates in analyzing what action plan
needs to be taken to achieve system requirements prescribed objective and what things, tools
would be required to achieve that objective. It assists in converting these plans into measurable
goals. In our project on e-commerce systems, based upon the criterion we have decided to
automate the system. Using the Web or in-store kiosks, customers will be able to search for and
purchase digital music downloads.
By implementing feasibility analysis, we have been able to build effective system within short
time span and within limited budget.
IV Discuss the components of a feasibility report.
A feasibility analysis evaluates the project’s potential for success. There are five types of
feasibility studies - the separate areas a feasibility study considers, described below.
1. Technical feasibility
This review focuses on the technical resources available to the organization. The technical
feasibility is also related to the evaluation of the hardware, software, and other technical
requirements of the proposed system. This technical feasibility study reports whether the exact
necessary technology and resources exist that will be used for project development. Along with
that, the feasibility study also analyzes the technical skills and capabilities of the engineering
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team, whether the existing technology can be used or not, and whether maintenance and
upgrades are easy or not for the technology. selected, etc.
Tune Source's e-commerce system can be built within the prescribed budget. It is a small but
very effective project which will handle multiple tasks simultaneously and reduce human effort,
time and cost. The IT department at Tune Source has become experienced with Internet
technology as it has worked with the ISP to maintain the site.
2. Operational feasibility
This review involves doing a study to analyze and determine whether - and to what extent - the
organization's needs can be met by project completion. The operational feasibility studies also
examine how a project plan meets the requirements identified during the requirements
analysis phase of system development.
3. Economic feasibility
In the economic feasibility study, project costs and benefits are analyzed, helping organizations
determine the viability, costs and benefits associated with the project before funding is
allocated. According to this feasibility study, a detailed analysis to be done will be the
development cost of the project, including all costs required for final development such as
required hardware and software resources, design and development costs and operating costs,
etc. It is then analyzed to see if the project will bring financial benefits to the organization.
Yes, Tune Source's e-commerce system is a cost effective and reasonable project. A meaningful
project has been created in small budget. This project will automate the entire library system
and will save lot of time, cost and effort of staff.
4. Legal feasibility
This review investigates whether any aspect of the proposed project conflicts with legal
requirements like zoning law, data protection behavior or social media law. Overall it can be
said that Legal Feasibility Study is study to know if proposed project conform legal and ethical
requirements.
Our project must comply with local data protection regulations and state laws.
5. Schedule feasibility
This rating is the most important to the success of the project; after all, a project will fail if it is
not completed on time. In the feasibility of planning, an organization estimates how much time
the project will take to complete. The scheduled feasibility also depends upon available
manpower and economic condition as well.
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V Technical solutions
a) Front-end
Figure 7. Front end
Front End is a way of calling a process using HTML, CSS, JavaScript to design and build interfaces
for websites or web applications so that users can view and interact directly on them.
Languages for Front End development include:
- HTML
- CSS
- Javascript
However, to code quickly and quickly, we can use additional frameworks or libraries such as:
Bootstrap, jQuery, AngularJS, React JS, Vue JS, EmberJS ...
b) Back-end
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Figure 8. Back end
Back-end deals with what content you're serving to the client and how you're serving that
content.
The back end of a website consists of a server, an application, and a database. A back-end
developer builds and maintains technology that powers those components, allowing the front-
end part of a website to survive.
Back End Developer is the one who decides how the website is run. Very important person.
Server-side languages for writing back-end:
- C #,
- Java
- Python
- Ruby, ...
The web frameworks come with these languages: ASP.NETMVC, Spring, Django, Rails ...
c) Capabilities and relationships between front-end and back-end website technologies
The front end of a website is the part that users interact with. Everything that you see when
you’re navigating around the Internet, from fonts and colors to dropdown menus and sliders, is
a combo of HTML, CSS, and JavaScript being controlled by your computer’s browser. Backend
developer is responsible for this ‘not visual’ part of application. If there is need to save some
information, it creates connection to DB and can do CRUD (create, read, update, delete)
operation on records.
Frontend developer is responsible for ‘visual’ part of application. The back end of a website
consists of a server, an application, and a database. A back-end developer builds and maintains
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the technology that powers those components which, together, enable the user-facing side of
the website to even exist in the first place.
Relationship between them is really close. If you want to develop good products, you have to
have a harmonious team. Cooperation between the two types of developers is important at the
start of the project. They have to set up some data schema and authorization type for the
project.
Compare front end and back end:
Front end Back end
- Markup and web languages such as
HTML, CSS, and Javascript
- Asynchronous requests and Ajax
- Specialized web editing software
- Image editing
- Accessibility
- Cross-browser issues
- Search engine optimization
- Programming and scripting such as
Python, Ruby and/ or Perl
- Server architecture
- Database administration
- Scalability
- Security
- Data transformation
- Backup
C. CONCLUSION
Software testing is an inseparable activity in software development. Knowing the soft
development model will help us to have a vision and build the correct, efficient and appropriate
test operation. In short, in this report, I described different software development lifecycles and
explained the importance of a feasibility study.
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D.REFERENCES
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disadvantages.html
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