This is about software engineering.Software engineers apply engineering principles and knowledge of programming languages to build software solutions for end users. Software engineers design and develop computer games, business applications, operating systems, network control systems, and middleware—to name just a few of the many career paths available.
The document discusses several system development life cycle (SDLC) models including waterfall, iterative, incremental, spiral, RAD, concurrent, and unified process models. The key phases of SDLC are defined as preliminary survey, analysis, design, implementation, post-implementation/maintenance, and project termination. Each model takes different approaches such as sequential, iterative, incremental, or concurrent development through the SDLC phases.
The document discusses various software development process models. It describes the waterfall model, which involves sequential phases from requirements to maintenance. The main drawback is difficulty accommodating changes after a phase is complete. The document also covers prototyping, rapid application development (RAD), incremental development, and spiral development - all of which allow for more iterative processes and incorporating feedback.
Evolution of software; Characteristics of software; Software applications; Components of software; Software myths; Software problems; Software reuse; Overview of risk management; Process visibility; Professional responsibility.
The document discusses various topics related to software engineering including:
1. It defines software and describes attributes of good software such as functionality, maintainability, dependability, and usability.
2. It explains that software engineering is concerned with all aspects of software production, whereas computer science focuses more on theory and fundamentals.
3. Key attributes of good software are discussed including maintainability, dependability, efficiency, and acceptability.
4. Various software engineering models such as waterfall, prototyping, spiral, and agile models are briefly introduced.
The document discusses several software development life cycle (SDLC) models including waterfall, V-shaped, prototyping, incremental, spiral, rapid application development (RAD), dynamic systems development method (DSDM), adaptive software development, and agile methods. It provides an overview of the key characteristics, strengths, weaknesses, and types of projects that each model is best suited for. Tailored SDLC models are recommended to customize processes based on specific project needs and risks.
The document discusses several software development process models including waterfall, iterative development, prototyping, RAD, spiral, RUP, and agile processes. The waterfall model is a linear sequential process while iterative development allows for incremental improvements. Prototyping allows users to provide early feedback. RAD combines waterfall and prototyping and emphasizes rapid development. Spiral model iterates through risk analysis, development, and planning phases. RUP is object-oriented and divided into cycles. Agile processes emphasize working software, incremental delivery, flexibility, and customer involvement.
This document discusses different process models used in software development. It describes the key phases and characteristics of several common process models including waterfall, prototyping, V-model, incremental, iterative, spiral and agile development models. The waterfall model involves sequential phases from requirements to maintenance without iteration. Prototyping allows for user feedback earlier. The V-model adds verification and validation phases. Incremental and iterative models divide the work into smaller chunks to allow for iteration and user feedback throughout development.
The document discusses several system development life cycle (SDLC) models including waterfall, iterative, incremental, spiral, RAD, concurrent, and unified process models. The key phases of SDLC are defined as preliminary survey, analysis, design, implementation, post-implementation/maintenance, and project termination. Each model takes different approaches such as sequential, iterative, incremental, or concurrent development through the SDLC phases.
The document discusses various software development process models. It describes the waterfall model, which involves sequential phases from requirements to maintenance. The main drawback is difficulty accommodating changes after a phase is complete. The document also covers prototyping, rapid application development (RAD), incremental development, and spiral development - all of which allow for more iterative processes and incorporating feedback.
Evolution of software; Characteristics of software; Software applications; Components of software; Software myths; Software problems; Software reuse; Overview of risk management; Process visibility; Professional responsibility.
The document discusses various topics related to software engineering including:
1. It defines software and describes attributes of good software such as functionality, maintainability, dependability, and usability.
2. It explains that software engineering is concerned with all aspects of software production, whereas computer science focuses more on theory and fundamentals.
3. Key attributes of good software are discussed including maintainability, dependability, efficiency, and acceptability.
4. Various software engineering models such as waterfall, prototyping, spiral, and agile models are briefly introduced.
The document discusses several software development life cycle (SDLC) models including waterfall, V-shaped, prototyping, incremental, spiral, rapid application development (RAD), dynamic systems development method (DSDM), adaptive software development, and agile methods. It provides an overview of the key characteristics, strengths, weaknesses, and types of projects that each model is best suited for. Tailored SDLC models are recommended to customize processes based on specific project needs and risks.
The document discusses several software development process models including waterfall, iterative development, prototyping, RAD, spiral, RUP, and agile processes. The waterfall model is a linear sequential process while iterative development allows for incremental improvements. Prototyping allows users to provide early feedback. RAD combines waterfall and prototyping and emphasizes rapid development. Spiral model iterates through risk analysis, development, and planning phases. RUP is object-oriented and divided into cycles. Agile processes emphasize working software, incremental delivery, flexibility, and customer involvement.
This document discusses different process models used in software development. It describes the key phases and characteristics of several common process models including waterfall, prototyping, V-model, incremental, iterative, spiral and agile development models. The waterfall model involves sequential phases from requirements to maintenance without iteration. Prototyping allows for user feedback earlier. The V-model adds verification and validation phases. Incremental and iterative models divide the work into smaller chunks to allow for iteration and user feedback throughout development.
Elementary Probability theory Chapter 2.pptxethiouniverse
The document discusses various software process models including waterfall, iterative, incremental, evolutionary (prototyping and spiral), and component-based development models. It describes the key activities and characteristics of each model and discusses when each may be applicable. The waterfall model presents a linear sequential flow while evolutionary models like prototyping and spiral are iterative and incremental to accommodate changing requirements.
Software Process in Software Engineering SE3koolkampus
The document introduces software process models and describes three generic models: waterfall, evolutionary development, and component-based development. It also covers the Rational Unified Process model and discusses how computer-aided software engineering (CASE) tools can support software development processes.
Process models are not perfect, but provide road map for software engineering work. Software models provide stability, control, and organization to a process that if not managed can easily get out of control
Software process models are adapted to meet the needs of software engineers and managers for a specific project.
The document discusses several software development life cycle (SDLC) models including waterfall, V-shaped, prototyping, rapid application development (RAD), incremental, spiral, and timeboxing. It provides descriptions of each model including typical steps, strengths, weaknesses, and when each model is best suited. It also discusses capability maturity model (CMM) levels and how changing the lifecycle model can impact development speed, quality, visibility, overhead, risk, and customer relations.
This document discusses several software development models and practices. It describes the waterfall model which involves sequential stages of requirement analysis, design, implementation, testing, and maintenance. It also covers prototyping, rapid application development (RAD), and component assembly models which are more iterative in nature. The prototyping model involves creating prototypes to help define requirements, RAD emphasizes reuse and short development cycles, and component assembly focuses on reusing existing software components.
The document introduces software process models including the waterfall model, evolutionary development, and component-based software engineering. It describes the Rational Unified Process model and discusses key process activities like requirements engineering, design, implementation, testing, and evolution. Computer-aided software engineering tools are introduced as a way to support various activities in the software development process.
The document introduces software process models and describes three generic models: waterfall, evolutionary development, and component-based development. It also outlines the software development process including requirements engineering, design, implementation, testing, and evolution. The Rational Unified Process model is introduced as a modern iterative process model. Computer-aided software engineering tools are discussed as a way to support software process activities.
The document introduces software process models including the waterfall model, evolutionary development, and component-based software engineering. It describes the Rational Unified Process model and discusses key process activities like requirements engineering, design, implementation, testing, and evolution. Computer-aided software engineering tools are introduced as a way to support various activities in the software development process.
The document introduces software process models and describes three generic models: waterfall, evolutionary development, and component-based development. It also covers the Rational Unified Process model and discusses how computer-aided software engineering (CASE) tools can support software processes. Key activities like requirements, design, implementation, testing, and evolution are defined.
This document provides an overview of different software process models. It discusses the build and fix model, why models are needed to address issues like schedule and cost overruns. It covers process models as a "black box" and "white box" approach. Prescriptive models advocate an orderly approach and include activities like communication, planning, modeling etc. The waterfall model is described as having sequential phases of requirements, design, implementation, testing and maintenance. Limitations are noted. Incremental process models deliver software in increments that build on each other. RAD aims for a very short development cycle through reuse. Evolutionary models produce increasingly complete versions through iterations like prototyping, the spiral model and concurrent development.
This document provides an overview of different software process models. It discusses the build and fix model, why models are needed to address issues like schedule and cost overruns. It covers process models as a "black box" and "white box" approach. Prescriptive models advocate an orderly approach and include activities like communication, planning, modeling etc. The waterfall model is described as having sequential phases of requirements, design, implementation, testing and maintenance. Limitations are noted. Incremental process models deliver software in increments. RAD aims for a very short development cycle through reuse. Evolutionary models produce increasingly complete versions through iterations, such as with prototyping, the spiral model and concurrent development.
ISE_Lecture Week 2-SW Process Models.pptHumzaWaris1
The document discusses various software development processes. It begins by defining a software process as a framework that describes the activities performed at each stage of a project. It then categorizes common activities as software specification, development, validation, and evolution. The document goes on to describe plan-driven and agile processes, and notes that most practical processes include elements of both. It provides details on specific process models like waterfall, V-model, prototyping, incremental development, component-based development, and spiral model.
The document discusses several software engineering process models. It begins by defining a generic process model with five framework activities: communication, planning, modeling, construction, and deployment. It then describes different types of process flows (linear, iterative, evolutionary, parallel). Next, it discusses prescriptive process models in more detail, including the waterfall model, incremental process models, and evolutionary models like prototyping and spiral. For each model, it provides an overview and highlights advantages and disadvantages.
Software development process models
Rapid Application Development (RAD) Model
Evolutionary Process Models
Spiral Model
THE FORMAL METHODS MODEL
Specialized Process Models
The Concurrent Development Model
The document discusses different software process models. It describes the waterfall model, which involves sequential phases of requirement analysis, design, implementation, testing, and maintenance. The waterfall model suggests a systematic approach but real projects rarely follow sequential phases and instead involve overlap and feedback between phases. The document also briefly describes the build-and-fix model, which develops software without specifications or design and relies on repeated modifications until requirements are met.
Miss Aster Noor introduces the concepts of software processes and process models. The chapter covers software process models like waterfall, incremental development, and integration/configuration. It discusses the core process activities of requirements engineering, development, testing, and evolution. The chapter aims to explain why processes must adapt to changes and how process improvement affects quality.
The document discusses and compares several software development life cycle (SDLC) models:
1) The waterfall model is a linear sequential flow where progress flows steadily through phases without backtracking. It is best for projects with clearly defined requirements.
2) The V-shaped model extends the waterfall model with early testing. It works well when requirements are easily understood.
3) The spiral model combines prototyping and risk assessment in cycles. It is favored for large, expensive projects built in phases.
4) The iterative model develops a system through repeated cycles and smaller portions, allowing learning from earlier versions. It produces value early and accommodates some changes.
5) The concurrent model develops tasks and states concurrently through framework
The document discusses software processes and models. It describes objectives of introducing process models and activities like requirements engineering, design, testing and evolution. Generic process models covered are waterfall, evolutionary development and component-based engineering. Iterative models like incremental delivery and spiral development are also introduced. The Rational Unified Process model and role of computer-aided software engineering in supporting process activities are also summarized.
The most common measures of central tendency are the arithmetic mean, the median, and the mode. A middle tendency can be calculated for either a finite set of values or for a theoretical distribution, such as the normal distribution. Occasionally authors use central tendency to denote "the tendency of quantitative data to cluster around some central value."[2][3]
The central tendency of a distribution is typically contrasted with its dispersion or variability; dispersion and central tendency are the often characterized properties of distributions. Analysis may judge whether data has a strong or a weak central tendency based on its dispersion.
Software Description
How to careate artchitectual design
Software quality aattribute
Software management and how to design a good software with basic tools and rules this may follow the proper road map of design and arthitevture design After analysis phase the next step is dessign in sdlc model
Elementary Probability theory Chapter 2.pptxethiouniverse
The document discusses various software process models including waterfall, iterative, incremental, evolutionary (prototyping and spiral), and component-based development models. It describes the key activities and characteristics of each model and discusses when each may be applicable. The waterfall model presents a linear sequential flow while evolutionary models like prototyping and spiral are iterative and incremental to accommodate changing requirements.
Software Process in Software Engineering SE3koolkampus
The document introduces software process models and describes three generic models: waterfall, evolutionary development, and component-based development. It also covers the Rational Unified Process model and discusses how computer-aided software engineering (CASE) tools can support software development processes.
Process models are not perfect, but provide road map for software engineering work. Software models provide stability, control, and organization to a process that if not managed can easily get out of control
Software process models are adapted to meet the needs of software engineers and managers for a specific project.
The document discusses several software development life cycle (SDLC) models including waterfall, V-shaped, prototyping, rapid application development (RAD), incremental, spiral, and timeboxing. It provides descriptions of each model including typical steps, strengths, weaknesses, and when each model is best suited. It also discusses capability maturity model (CMM) levels and how changing the lifecycle model can impact development speed, quality, visibility, overhead, risk, and customer relations.
This document discusses several software development models and practices. It describes the waterfall model which involves sequential stages of requirement analysis, design, implementation, testing, and maintenance. It also covers prototyping, rapid application development (RAD), and component assembly models which are more iterative in nature. The prototyping model involves creating prototypes to help define requirements, RAD emphasizes reuse and short development cycles, and component assembly focuses on reusing existing software components.
The document introduces software process models including the waterfall model, evolutionary development, and component-based software engineering. It describes the Rational Unified Process model and discusses key process activities like requirements engineering, design, implementation, testing, and evolution. Computer-aided software engineering tools are introduced as a way to support various activities in the software development process.
The document introduces software process models and describes three generic models: waterfall, evolutionary development, and component-based development. It also outlines the software development process including requirements engineering, design, implementation, testing, and evolution. The Rational Unified Process model is introduced as a modern iterative process model. Computer-aided software engineering tools are discussed as a way to support software process activities.
The document introduces software process models including the waterfall model, evolutionary development, and component-based software engineering. It describes the Rational Unified Process model and discusses key process activities like requirements engineering, design, implementation, testing, and evolution. Computer-aided software engineering tools are introduced as a way to support various activities in the software development process.
The document introduces software process models and describes three generic models: waterfall, evolutionary development, and component-based development. It also covers the Rational Unified Process model and discusses how computer-aided software engineering (CASE) tools can support software processes. Key activities like requirements, design, implementation, testing, and evolution are defined.
This document provides an overview of different software process models. It discusses the build and fix model, why models are needed to address issues like schedule and cost overruns. It covers process models as a "black box" and "white box" approach. Prescriptive models advocate an orderly approach and include activities like communication, planning, modeling etc. The waterfall model is described as having sequential phases of requirements, design, implementation, testing and maintenance. Limitations are noted. Incremental process models deliver software in increments that build on each other. RAD aims for a very short development cycle through reuse. Evolutionary models produce increasingly complete versions through iterations like prototyping, the spiral model and concurrent development.
This document provides an overview of different software process models. It discusses the build and fix model, why models are needed to address issues like schedule and cost overruns. It covers process models as a "black box" and "white box" approach. Prescriptive models advocate an orderly approach and include activities like communication, planning, modeling etc. The waterfall model is described as having sequential phases of requirements, design, implementation, testing and maintenance. Limitations are noted. Incremental process models deliver software in increments. RAD aims for a very short development cycle through reuse. Evolutionary models produce increasingly complete versions through iterations, such as with prototyping, the spiral model and concurrent development.
ISE_Lecture Week 2-SW Process Models.pptHumzaWaris1
The document discusses various software development processes. It begins by defining a software process as a framework that describes the activities performed at each stage of a project. It then categorizes common activities as software specification, development, validation, and evolution. The document goes on to describe plan-driven and agile processes, and notes that most practical processes include elements of both. It provides details on specific process models like waterfall, V-model, prototyping, incremental development, component-based development, and spiral model.
The document discusses several software engineering process models. It begins by defining a generic process model with five framework activities: communication, planning, modeling, construction, and deployment. It then describes different types of process flows (linear, iterative, evolutionary, parallel). Next, it discusses prescriptive process models in more detail, including the waterfall model, incremental process models, and evolutionary models like prototyping and spiral. For each model, it provides an overview and highlights advantages and disadvantages.
Software development process models
Rapid Application Development (RAD) Model
Evolutionary Process Models
Spiral Model
THE FORMAL METHODS MODEL
Specialized Process Models
The Concurrent Development Model
The document discusses different software process models. It describes the waterfall model, which involves sequential phases of requirement analysis, design, implementation, testing, and maintenance. The waterfall model suggests a systematic approach but real projects rarely follow sequential phases and instead involve overlap and feedback between phases. The document also briefly describes the build-and-fix model, which develops software without specifications or design and relies on repeated modifications until requirements are met.
Miss Aster Noor introduces the concepts of software processes and process models. The chapter covers software process models like waterfall, incremental development, and integration/configuration. It discusses the core process activities of requirements engineering, development, testing, and evolution. The chapter aims to explain why processes must adapt to changes and how process improvement affects quality.
The document discusses and compares several software development life cycle (SDLC) models:
1) The waterfall model is a linear sequential flow where progress flows steadily through phases without backtracking. It is best for projects with clearly defined requirements.
2) The V-shaped model extends the waterfall model with early testing. It works well when requirements are easily understood.
3) The spiral model combines prototyping and risk assessment in cycles. It is favored for large, expensive projects built in phases.
4) The iterative model develops a system through repeated cycles and smaller portions, allowing learning from earlier versions. It produces value early and accommodates some changes.
5) The concurrent model develops tasks and states concurrently through framework
The document discusses software processes and models. It describes objectives of introducing process models and activities like requirements engineering, design, testing and evolution. Generic process models covered are waterfall, evolutionary development and component-based engineering. Iterative models like incremental delivery and spiral development are also introduced. The Rational Unified Process model and role of computer-aided software engineering in supporting process activities are also summarized.
The most common measures of central tendency are the arithmetic mean, the median, and the mode. A middle tendency can be calculated for either a finite set of values or for a theoretical distribution, such as the normal distribution. Occasionally authors use central tendency to denote "the tendency of quantitative data to cluster around some central value."[2][3]
The central tendency of a distribution is typically contrasted with its dispersion or variability; dispersion and central tendency are the often characterized properties of distributions. Analysis may judge whether data has a strong or a weak central tendency based on its dispersion.
Software Description
How to careate artchitectual design
Software quality aattribute
Software management and how to design a good software with basic tools and rules this may follow the proper road map of design and arthitevture design After analysis phase the next step is dessign in sdlc model
The simplest and most common form of mathematical induction infers that a statement involving a natural number n (that is, an integer n ≥ 0 or 1) holds for all values of n. The proof consists of two steps:
The base case (or initial case): prove that the statement holds for 0, or 1.
The induction step (or inductive step, or step case): prove that for every n, if the statement holds for n, then it holds for n + 1. In other words, assume that the statement holds for some arbitrary natural number n, and prove that the statement holds for n + 1
The simplest and most common form of mathematical induction infers that a statement involving a natural number n (that is, an integer n ≥ 0 or 1) holds for all values of n. The proof consists of two steps:
The base case (or initial case): prove that the statement holds for 0, or 1.
The induction step (or inductive step, or step case): prove that for every n, if the statement holds for n, then it holds for n + 1. In other words, assume that the statement holds for some arbitrary natural number n, and prove that the statement holds for n + 1
The document discusses various requirements modeling approaches used in software engineering. It describes goals of analysis modeling such as providing the first technical representation of a system, partitioning the system, and differentiating essential from implementation information. It then summarizes four main types of modeling: flow-oriented modeling depicts how data is transformed; scenario-based modeling represents the system from the user's perspective; class-based modeling defines objects and relationships; and behavioral modeling depicts how events impact class states. Finally, it provides examples of using data flow diagrams to model a lemonade stand system.
Requirement engineering involves several key tasks: inception to establish project scope, elicitation to determine user needs, elaboration to refine requirements, negotiation to resolve conflicts, validation to verify requirements, and management of changing requirements. Effective elicitation uses techniques like interviews, scenarios, and ethnography to understand stakeholders and identify general, expected, and unexpected requirements while addressing problems of scope, understanding, volatility, and communication barriers. Requirements are further developed through analysis, modeling, prioritization, and specification documentation. Regular reviews validate that requirements define the desired system.
Cleanliness is important for health, mental well-being, social perception, and productivity. It is emphasized culturally and religiously in Pakistani society. The document discusses different types of cleanliness and how maintaining cleanliness through practices like hand washing and hygiene can reduce disease. It also notes that cleanliness is associated with purity in Islam and encouraged by sayings of the Prophet Muhammad. Barriers to cleanliness are a lack of access to water, sanitation, education, or economic constraints, but working together could help communities prioritize cleanliness.
Get Success with the Latest UiPath UIPATH-ADPV1 Exam Dumps (V11.02) 2024yarusun
Are you worried about your preparation for the UiPath Power Platform Functional Consultant Certification Exam? You can come to DumpsBase to download the latest UiPath UIPATH-ADPV1 exam dumps (V11.02) to evaluate your preparation for the UIPATH-ADPV1 exam with the PDF format and testing engine software. The latest UiPath UIPATH-ADPV1 exam questions and answers go over every subject on the exam so you can easily understand them. You won't need to worry about passing the UIPATH-ADPV1 exam if you master all of these UiPath UIPATH-ADPV1 dumps (V11.02) of DumpsBase. #UIPATH-ADPV1 Dumps #UIPATH-ADPV1 #UIPATH-ADPV1 Exam Dumps
The Science of Learning: implications for modern teachingDerek Wenmoth
Keynote presentation to the Educational Leaders hui Kōkiritia Marautanga held in Auckland on 26 June 2024. Provides a high level overview of the history and development of the science of learning, and implications for the design of learning in our modern schools and classrooms.
Cross-Cultural Leadership and CommunicationMattVassar1
Business is done in many different ways across the world. How you connect with colleagues and communicate feedback constructively differs tremendously depending on where a person comes from. Drawing on the culture map from the cultural anthropologist, Erin Meyer, this class discusses how best to manage effectively across the invisible lines of culture.
Information and Communication Technology in EducationMJDuyan
(𝐓𝐋𝐄 𝟏𝟎𝟎) (𝐋𝐞𝐬𝐬𝐨𝐧 2)-𝐏𝐫𝐞𝐥𝐢𝐦𝐬
𝐄𝐱𝐩𝐥𝐚𝐢𝐧 𝐭𝐡𝐞 𝐈𝐂𝐓 𝐢𝐧 𝐞𝐝𝐮𝐜𝐚𝐭𝐢𝐨𝐧:
Students will be able to explain the role and impact of Information and Communication Technology (ICT) in education. They will understand how ICT tools, such as computers, the internet, and educational software, enhance learning and teaching processes. By exploring various ICT applications, students will recognize how these technologies facilitate access to information, improve communication, support collaboration, and enable personalized learning experiences.
𝐃𝐢𝐬𝐜𝐮𝐬𝐬 𝐭𝐡𝐞 𝐫𝐞𝐥𝐢𝐚𝐛𝐥𝐞 𝐬𝐨𝐮𝐫𝐜𝐞𝐬 𝐨𝐧 𝐭𝐡𝐞 𝐢𝐧𝐭𝐞𝐫𝐧𝐞𝐭:
-Students will be able to discuss what constitutes reliable sources on the internet. They will learn to identify key characteristics of trustworthy information, such as credibility, accuracy, and authority. By examining different types of online sources, students will develop skills to evaluate the reliability of websites and content, ensuring they can distinguish between reputable information and misinformation.
2. The Software
Process
Process defines a framework for a set
of key process areas that must be
established for effective delivery of
software engineering technology.
A structured set of activities required
to develop a software system.
3. Software process descriptions
When we describe and discuss processes, we usually talk about
the activities in these processes such as specifying a data
model, designing a user interface, etc. and the ordering of
these activities.
Process descriptions may also include:
Products, which are the outcomes of a process activity;
Roles, which reflect the responsibilities of the people
involved in the process;
Pre- and post-conditions, which are statements that are
true before and after a process activity has been enacted or
a product produced.
4. Plan-driven and agile processes
Plan-driven processes are processes where all of the
process activities are planned in advance and progress is
measured against this plan.
In agile processes, planning is incremental, and it is
easier to change the process to reflect changing customer
requirements.
In practice, most practical processes include elements of
both plan-driven and agile approaches.
There are no right or wrong software processes.
5. Software process activities
Many different software processes but all involve:
Software specification, where customers and engineers define the software
that is to be produced and the constraints on its operation.
Software development, where the software is designed and programmed.
Software validation, where the software is checked to ensure that it is what
the customer requires.
Software evolution, where the software is modified to reflect changing
customer and market requirements.
7. Software process models
A software process model is an abstract representation of a process. It
presents a description of a process from some particular perspective.
The waterfall model
Plan-driven model. Separate and distinct phases of specification and development.
Incremental development
Specification, development and validation are interleaved. May be plan-driven or
agile.
Integration and configuration
The system is assembled from existing configurable components. May be plan-driven
or agile.
In practice, most large systems are developed using a process that
incorporates elements from all of these models.
8. SDLC Model by
Summerville
Requirements Definition
System and Software Design
Implementation and Unit testing
Integration and System Testing
Operation and maintenance
10. The Waterfall Model
It is the oldest paradigm for SE. When requirements are well
defined and reasonably stable, it leads to a top-down fashion.
The classic life cycle suggests a systematic, sequential approach
to software development.
11.
12. Waterfall model phases
There are separate identified phases in the waterfall model:
Requirements analysis and definition
System and software design
Implementation and unit testing
Integration and system testing
Operation and maintenance
The main drawback of the waterfall model is the difficulty of
accommodating change after the process is underway. In principle, a phase
has to be complete before moving onto the next phase.
13. Waterfall model problems
Inflexible partitioning of the
project into distinct stages makes
it difficult to respond to changing
customer requirements.
• Therefore, this model is only
appropriate when the
requirements are well-
understood and changes will be
fairly limited during the design
process.
• Few business systems have
stable requirements.
The waterfall model is mostly used
for large systems engineering
projects where a system is
developed at several sites.
• In those circumstances, the plan-
driven nature of the waterfall
model helps coordinate the
work.
14. The V-Model
A variation of waterfall model
depicts the relationship of
quality assurance actions to
the actions associated with
communication, modeling and
early code construction
activities.
Team first moves down the left
side of the V to refine the
problem requirements. Once
code is generated, the team
moves up the right side of the
V, performing a series of tests
that validate each of the
models created as the team
moved down the left side.
20. The Incremental Model
When initial requirements are reasonably well defined, but the
overall scope of the development effort prevents a purely linear
process. A convincing need to expand a limited set of new functions
to a later system release.
It combines elements of water fall model in an iterative way. Each
linear sequence produces deliverable increments of the software.
The first increment is often a CORE PRODUCT with many additional
features. Users use it and evaluate it with more modifications to
better meet the needs.
21. Incremental
development
benefits
• The amount of analysis and
documentation that has to be
redone is much less than is
required with the waterfall model.
The cost of
accommodating
changing customer
requirements is
reduced.
• Customers can comment on
demonstrations of the software
and see how much has been
implemented.
It is easier to get
customer feedback
on the development
work that has been
done.
• Customers are able to use and gain
value from the software earlier
than is possible with a waterfall
process.
More rapid delivery
and deployment of
useful software to
the customer is
possible.
22. Incremental
development
problems
• Managers need regular deliverables to
measure progress. If systems are developed
quickly, it is not cost-effective to produce
documents that reflect every version of the
system.
The process is not visible.
• Unless time and money is spent on
refactoring to improve the software, regular
change tends to corrupt its structure.
Incorporating further software changes
becomes increasingly difficult and costly.
System structure tends to degrade
as new increments are added.
23. Pros and cons
Generates working software quickly and early during the
software life cycle.
More flexible – less costly to change scope and requirements
Easier to test and debug during a smaller iteration.
Easier to manage risk because risky pieces are identified and
handled during its iteration.
Each iteration is an easily managed milestone
Each phase of an iteration is rigid and do not overlap each
other
Problems may arise pertaining to system architecture because
not all requirements are gathered up front for the entire
software life cycle.
24. RAD Model
Rapid application development (RAD) is an incremental software
development process model
It emphasizes an extremely short development cycle
The RAD model is a “high-speed” adaptation of the linear sequential
model in which rapid development is achieved by using component-
based construction. If requirements are well understood and project
scope is constrained, the RAD process enables a development team
to create a “fully functional system” within very short time
periods(60-90 days)
25. Pros and cons
Increases reusability of components
Progress can be measured.
Encourages customer feedback
Quick initial reviews occur
Reduced development time
Inapplicable to cheaper projects as cost of modeling and
automated code generation is very high.
It is suitable for systems that are component based and scalable.
Requires highly skilled developers/designers.
Requires user involvement throughout the life cycle.
27. Evolutionary Models
Software system evolves over time as requirements often change as
development proceeds. Thus, a straight line to a complete end product is not
possible. However, a limited version must be delivered to meet competitive
pressure.
Usually a set of core product or system requirements is well understood, but
the details and extension have yet to be defined.
You need a process model that has been explicitly designed to accommodate
a product that evolved over time.
It is iterative that enables you to develop increasingly more complete version
of the software.
Two types are introduced, namely Prototyping and Spiral models.
28. Evolutionary Models: Prototyping
When to use: Customer defines a set of GENERAL OBJECTIVES but does not
identify detailed requirements for functions and features. Or Developer may
be unsure of the efficiency of an algorithm, the form that human computer
interaction should take.
What step: Begins with communication by meeting with stakeholders to define
the objective, identify whatever requirements are known, outline areas where
further definition is mandatory. A quick plan for prototyping and modeling
(quick design) occur. Quick design focuses on a representation of those
aspects the software that will be visible to end users. ( interface and output).
Design leads to the construction of a prototype which will be deployed and
evaluated. Stakeholder’s comments will be used to refine requirements.
Both stakeholders and software engineers like the prototyping paradigm. Users
get a feel for the actual system, and developers get to build something
immediately. However, engineers may make compromises in order to get a
prototype working quickly. The less-than-ideal choice may be adopted forever
after you get used to it.
29. Evolutionary Models: Prototyping
prototyping, analysis and design
Construction
of prototype
communication
Quick
plan
Modeling
Quick design
Construction
of prototype
Deployment
delivery &
feedback
30. Pros and cons
Model allows a high user interface of the customer.
It provide actual look and feel of system being developed for
customer review and feedback about the system functionality.
Errors and issues can be detected very easily.
Risk of insufficient requirement analysis owing to too much
dependency on prototype.
Users may get confused in the prototypes and actual systems.
Developers may try to reuse the existing prototypes to build
the actual system, even when it’s not technically feasible.
Less-than-ideal choice has now become an integral part of the
system
31. Evolutionary Models: The Spiral
Spiral model is one of the most important Software
Development Life Cycle models, which provides support
for Risk Handling. In its diagrammatic representation, it looks
like a spiral with many loops. The exact number of loops of the
spiral is unknown and can vary from project to project. Each
loop of the spiral is called a Phase of the software
development process. The exact number of phases needed to
develop the product can be varied by the project manager
depending upon the project risks. As the project manager
dynamically determines the number of phases, so the project
manager has an important role to develop a product using
spiral model.
33. Pros and cons
Highly flexible model
Risk handling
Fast and cost-effective development
Well-suited for large scale projects and mission-critical developments
Works well for complex projects
Monitoring is easy and effective
The end product can be highly customized
Can be expensive to implement – especially if spirals continue infinitely
The risk analysis aspect of the project may require specialist expertise
Not an ideal fit for smaller or low-risk projects
Success may depend greatly on the risk analysis
Documentation can be heavy, due to the number of intermediate stages
End of project may be difficult to define beforehand
34. Three Concerns on
Evolutionary Processes
First concern is that prototyping poses a problem to project planning
because of the uncertain number of cycles required to construct the
product.
Second, it does not establish the maximum speed of the evolution. If
the evolution occur too fast, without a period of relaxation, it is
certain that the process will fall into confusion. On the other hand if
the speed is too slow then productivity could be affected.
Third, software processes should be focused on flexibility and
extensibility rather than on high quality. We should prioritize the
speed of the development over zero defects. Extending the
development in order to reach high quality could result in a late
delivery of the product when the opportunity has disappeared.
35. Integration
and
configuration
Based on software reuse where systems are
integrated from existing components or
application systems (sometimes called COTS -
Commercial-off-the-shelf) systems).
Reused elements may be configured to adapt
their behaviour and functionality to a user’s
requirements
Reuse is now the standard approach for
building many types of business system
36. Reuse-Oriented Model
The reuse-oriented model, also called reuse-oriented development (ROD)
Method of software development in which a program is refined by producing
a sequence of prototypes called models
Each model is automatically derived from the preceding one according to a
sequence of defined rules.
37. Types of reusable software
Stand-alone application systems (sometimes called COTS) that are configured
for use in a particular environment.
Collections of objects that are developed as a package to be integrated with
a component framework such as .NET or J2EE.
Web services that are developed according to service standards and which are
available for remote invocation.
40. Advantages and disadvantages
Reduced costs and risks as less software is developed from scratch
Faster delivery and deployment of system
But requirements compromises are inevitable so system may not meet real
needs of users
Loss of control over evolution of reused system elements
41. Still Other Process Models
Component based development—the process
to apply when reuse is a development
objective (COTS)
Unified Process—a “use-case driven,
architecture-centric, iterative and
incremental” software process closely
aligned with the Unified Modeling Language
(UML) to model and develop object-oriented
system iteratively and incrementally.
42. Unified Modeling
Class Diagram (View System Architecture)
Use Case Diagram (View System Functionality)
Sequence Diagram (View System Behavior)
State Diagram (View System States)