Certificate Program in Business Analytics Introduction Making India Employable
Software Development Life Cycle SDLC stands for Software Development Life Cycle. SDLC is a process that consists of a series of planned activities to develop o SDLC 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 or alter the Software Products. Making India Employable
SDLC Steps Making India Employable
Detailed SDLC process Making India Employable
Different SDLC models • There are various software development life cycle models defined and designed which are followed during the software development process. • Each process model follows a Series of steps unique to its type to ensure success in the process of software development. Making India Employable
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. Making India Employable
Iterative Model • In the Iterative model, iterative process starts with a simple implementation of a small set of the software requirements • It iteratively enhances the evolving versions until the complete system is implemented and ready to be deployed. Making India Employable
Spiral Model • The spiral model combines the idea of iterative development with the systematic, controlled aspects of the waterfall model. • This Spiral model is a combination of iterative development process model and sequential linear development model • It allows incremental releases of the product or incremental refinement through each iteration around the spiral. Making India Employable
Rapid Application Development Making India Employable
V-Model Making India Employable
Agile Making India Employable
Traditional vs RAD Making India Employable
Waterfall SDLC Model • 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 the Waterfall model, typically, the outcome of one phase acts as the input for the next phase sequentially. Making India Employable
What is Software? • Software is a program or set of programs containing instructions that provide desired functionality. • Engineering is the process of designing and building something that serves a particular purpose and finds a cost-effective solution to problems. Making India Employable
Role of Software • As a product • It delivers the computing potential across networks • It acts as an information transformer because it produces, manages, acquires, modifies, displays, or transmits information. • As a vehicle for delivering a product • It provides system functionality (e.g., payroll system) • It controls other software (e.g., an operating system) • It helps build other software (e.g., software tools) Making India Employable
Objectives of Software Engineering: • Maintainability – It should be feasible for the software to evolve to meet changing requirements. • Efficiency – The software should not make wasteful use of computing devices such as memory, processor cycles, etc. • Correctness – A software product is correct if the different requirements as specified in the SRS document have been correctly implemented. • Reusability – A software product has good reusability if the different modules of the product can easily be reused to develop new products. • Testability – Here software facilitates both the establishment of test criteria and the evaluation of the software with respect to those criteria. Making India Employable
Objectives of Software Engineering: • Reliability – It is an attribute of software quality. The extent to which a program can be expected to perform its desired function, over an arbitrary time period. • Portability – In this case, the software can be transferred from one computer system or environment to another. • Adaptability – In this case, the software allows differing system constraints and the user needs to be satisfied by making changes to the software. • Interoperability – Capability of 2 or more functional units to process data cooperatively. Making India Employable
Classification of Software Making India Employable
Classification of Software • On the basis of application: On the basis of copyright • System Software • Commercial • Networking and Web Applications Software • Shareware • Embedded Software • Freeware • Reservation Software(slot blocking) • Public Domain • Business Software • Entertainment Software • Artificial Intelligence Software • Scientific Software • Utilities Software • Document Management Software Making India Employable
Classical Waterfall Model • The classical waterfall model is the basic software development life cycle model. It is very simple but idealistic. • The classical waterfall model divides the life cycle into a set of phases. This model considers that one phase can be started after the completion of the previous phase. Making India Employable
Stages of waterfall model-Feasibility study • Feasibility Study: The main goal of this Functional phase is to determine whether it would be Technical financially and technically feasible to Operational develop the software. Economical The feasibility study involves Legal & Statutory Schedule and Timeline • understanding the problem Environmental • Determining the various possible strategies to solve the problem. • Identified solutions are analyzed based on their benefits and drawbacks, • Best solution is chosen and all the other phases are carried out as per this solution strategy. Making India Employable
Stages of waterfall model- Requirements analysis study • Requirements analysis and specification: The aim of the requirement analysis and specification phase is to understand the exact requirements of the customer and document them properly. This phase consists of two different activities. • Requirement gathering and analysis: Firstly all the requirements regarding the software are gathered from the customer and then the gathered requirements are analyzed. The goal of the analysis part is to remove incompleteness and inconsistencies and resolve with customer. • Requirement specification: These analyzed requirements are documented in a software requirement specification (SRS) document. SRS document serves as a contract between the development team and customers. Any future dispute between the customers and the developers can be settled by examining the SRS document. Making India Employable
Stages of waterfall model- Requirements analysis study Making India Employable
Stages of waterfall model- Design • Design: The goal of this phase is to convert the requirements acquired in the SRS into a format that can be coded in a programming language. It includes high-level and detailed design as well as the overall software architecture. A Software Design Document is used to document all of this effort (SDD) Making India Employable
Stages of waterfall model- Design Making India Employable
Software Design Document Contents Making India Employable
Stages of waterfall model- Coding and Unit testing • Coding and Unit testing: In the coding phase software design is translated into source code using any suitable programming language. Thus each designed module is coded. The aim of the unit testing phase is to check whether each module is working properly or not. Making India Employable
Stages of waterfall model- Coding & unit Testing Making India Employable
Stages of waterfall model- Integration and System testing • Integration and System testing: Integration of different modules are undertaken soon after they have been coded and unit tested. During each integration step, previously planned modules are added to the partially integrated system and the resultant system is tested. Finally, after all the modules have been successfully integrated and tested, the full working system is obtained and system testing is carried out on this. System testing consists of three different kinds of testing activities as described below : Making India Employable
Stages of waterfall model- Integration and System testing Making India Employable
Stages of waterfall model- Integration and System testing System testing consists of three different kinds of testing activities as described below : • Alpha testing: Alpha testing is the system testing performed by the development team. • Beta testing: Beta testing is the system testing performed by a friendly set of customers. • Gamma testing: After the software has been delivered, the customer performed acceptance(gamma) testing to determine whether to accept the delivered software or reject it. Making India Employable
Testing stages Making India Employable
Stages of waterfall model- Deployment Making India Employable
Stages of waterfall model- Maintenance • Maintenance: Maintenance is the most important phase of a software life cycle. The effort spent on maintenance is 60% of the total effort spent to develop a full software. There are basically three types of maintenance : • Corrective Maintenance: This type of maintenance is carried out to correct errors that were not discovered during the product development phase. • Perfective Maintenance: This type of maintenance is carried out to enhance the functionalities of the system based on the customer’s request. • Adaptive Maintenance: Adaptive maintenance is usually required for porting the software to work in a new environment such as working on a new computer platform or with a new operating system. Making India Employable
Stages of waterfall model- Maintenance Making India Employable
Advantages of Classical Waterfall Model • This model is very simple and is easy to understand. • Phases in this model are processed one at a time. • Each stage in the model is clearly defined. • This model has very clear and well-understood milestones. • Process, actions and results are very well documented. • Reinforces good habits: define-before- design, design-before-code. • This model works well for smaller projects and projects where requirements are well understood. Making India Employable
Drawbacks of Classical Waterfall Model • No feedback path: since evolution of software is from one phase to another phase , It assumes that no error is ever committed by developers during any phase. Therefore, it does not incorporate any mechanism for error correction. • Difficult to accommodate change requests: It is difficult to accommodate any change requests after the requirements specification phase is complete. • No overlapping of phases: This model recommends that a new phase can start only after the completion of the previous phase. But in real projects, this can’t be maintained. To increase efficiency and reduce cost, phases may overlap. Making India Employable
Spiral Model • 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. Making India Employable
Phase of the Spiral Model • Each phase of the Spiral Model is divided into four quadrants as shown in the above figure. The functions of these four quadrants are discussed Objectives determination and identify Identify and resolve Risks: During the alternative solutions: Requirements are second quadrant, all the possible gathered from the customers and the solutions are evaluated to select the best objectives are identified, elaborated, and possible solution. Then the risks analyzed at the start of every phase. associated with that solution are Then alternative solutions possible for identified and the risks are resolved the phase are proposed in this quadrant. using the best possible strategy. At the end of this quadrant, the Prototype is built for the best possible solution. Making India Employable
Phase of the Spiral Model • Each phase of the Spiral Model is divided into four quadrants as shown in the above figure. The functions of these four quadrants are discussed Develop next version of the Review and plan for the next Phase: In Product: During the third quadrant, the the fourth quadrant, the Customers identified features are developed and evaluate the so far developed version of verified through testing. At the end of the the software. In the end, planning for the third quadrant, the next version of the next phase is started. software is available. Making India Employable
Advantages of Spiral Model • Risk Handling: The projects with many unknown risks that occur as the development proceeds, in that case, Spiral Model is the best development model to follow due to the risk analysis and risk handling at every phase. • Good for large projects: It is recommended to use the Spiral Model in large and complex projects. • Flexibility in Requirements: Change requests in the Requirements at later phase can be incorporated accurately by using this model. • Customer Satisfaction: Customer can see the development of the product at the early phase of the software development and thus, they habituated with the system by using it before completion of the total product. Making India Employable
Disadvantages of Spiral Model • Complex: The Spiral Model is much more complex than other SDLC models. • Expensive: Spiral Model is not suitable for small projects as it is expensive. • Too much dependability on Risk Analysis: The successful completion of the project is very much dependent on Risk Analysis. Without very highly experienced experts, it is going to be a failure to develop a project using this model. • Difficulty in time management: As the number of phases is unknown at the start of the project, so time estimation is very difficult. Making India Employable
V-Model The V-model is a type of SDLC model where process executes in a sequential manner in V-shape. It is also known as Verification and Validation model. It is based on the association of a testing phase for each corresponding development stage. Development of each step directly associated with the testing phase. The next phase starts only after completion of the previous phase i.e. for each development activity, there is a testing activity corresponding to it. Making India Employable
V model Verification: It involves Validation: It involves dynamic static analysis technique analysis technique (functional, (review) done without non-functional), testing done by executing code. It is the executing code. Validation is the process of evaluation of process to evaluate the software the product development after the completion of the phase to find whether development phase to determine specified requirements whether software meets the meet. customer expectations and requirements. V-Model contains Verification phases on one side of the Validation phases on the other side. Verification and Validation phases are joined by coding phase in V-shape. Thus it is called V-Model. Making India Employable
V-Model - Design Phase: • Requirement Analysis: This phase contains detailed communication with the customer to understand their requirements and expectations. This stage is known as Requirement Gathering. • System Design: This phase contains the system design and the complete hardware and communication setup for developing product. • Architectural Design: System design is broken down further into modules taking up different functionalities. The data transfer and communication between the internal modules and with the outside world (other systems) is clearly understood. • Module Design: In this phase the system breaks down into small modules. The detailed design of modules is specified, also known as Low-Level Design (LLD). Making India Employable
V-Model - • Unit Testing: Unit Test Plans are developed during module design phase. These Unit Test Plans are executed to eliminate bugs at code or unit level. • Integration testing: After completion of unit testing Integration testing is performed. In integration testing, the modules are integrated and the system is tested. Integration testing is performed on the Architecture design phase. This test verifies the communication of modules among themselves. • System Testing: System testing test the complete application with its functionality, inter dependency, and communication.It tests the functional and non-functional requirements of the developed application. • User Acceptance Testing (UAT): UAT is performed in a user environment that resembles the production environment. UAT verifies that the delivered system meets user’s requirement and system is ready for use in real world. Making India Employable
Principles of V-Model: • Large to Small: In V-Model, testing is done in a hierarchical perspective, For example, requirements identified by the project team, create High-Level Design, and Detailed Design phases of the project. As each of these phases is completed the requirements, they are defining become more and more refined and detailed. • Data/Process Integrity: This principle states that the successful design of any project requires the incorporation and cohesion of both data and processes. Process elements must be identified at each and every requirements. • Scalability: This principle states that the V-Model concept has the flexibility to accommodate any IT project irrespective of its size, complexity or duration. • Cross Referencing: Direct correlation between requirements and corresponding testing activity is known as cross-referencing. • Tangible Documentation: This principle states that every project needs to create a document. This documentation is required and applied by both the project development team and the support team. Documentation is used to maintaining the application once it is available in a production environment Making India Employable
Advantages of V-Model • This is a highly disciplined model and Phases are completed one at a time. • V-Model is used for small projects where project requirements are clear. • Simple and easy to understand and use. • This model focuses on verification and validation activities early in the life cycle thereby enhancing the probability of building an error- free and good quality product. • It enables project management to track progress accurately. Making India Employable
Disadvantages of V-Model • High risk and uncertainty. • It is not a good for complex and object-oriented projects. • It is not suitable for projects where requirements are not clear and contains high risk of changing. • This model does not support iteration of phases. • It does not easily handle concurrent events. Making India Employable
Selection of appropriate life cycle model for a project: • Selection of proper lifecycle model to complete a project is the most important task. It can be selected by keeping the advantages and disadvantages of various models in mind. The different issues that are analyzed before selecting a suitable life cycle model are given below • Characteristics of the software to be developed: • Characteristics of the development team: • Risk associated with the project: • Characteristics of the customer: Making India Employable
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