SDLC - Day 3
Disadvantages of Iterative model:
Each phase of an iteration is rigid with no overlaps Costly system architecture or design issues may arise because not all requirements are gathered up front for the entire lifecycle
Advantages of Iterative model:
In iterative model we can only create a high-level design of the application before we actually begin to build the product and define the design solution for the entire product. Later on we can design and built a skeleton version of that, and then evolved the design based on what had been built. In iterative model we are building and improving the product step by step. Hence we can track the defects at early stages. This avoids the downward flow of the defects. In iterative model we can get the reliable user feedback. When presenting sketches and blueprints of the product to users for their feedback, we are effectively asking them to imagine how the product will work. In iterative model less time is spent on documenting and more time is given for designing.
When to use iterative model:
Requirements of the complete system are clearly defined and understood. When the project is big. Major requirements must be defined; however, some details can evolve with time.
Advantages of using Waterfall?
ADVANTAGE The advantage of waterfall development is that it allows for departmentalization and control. A schedule can be set with deadlines for each stage of development and a product can proceed through the development process model phases one by one. Development moves from concept, through design, implementation, testing, installation, troubleshooting, and ends up at operation and maintenance. Each phase of development proceeds in strict order.
What is the Iterative [it - er- rative] model - SDLC?
An iterative life cycle model does not attempt to start with a full specification of requirements. Instead, development begins by specifying and implementing just part of the software, which can then be reviewed in order to identify further requirements. This process is then repeated, producing a new version of the software for each cycle of the model. - we create rough product or product piece in one iteration, then review it and improve it in next iteration and so on until it's finished.
Disadvantages of Waterfall?
DISADVANTAGE The disadvantage of waterfall development is that it does not allow for much reflection or revision. Once an application is in the testing stage, it is very difficult to go back and change something that was not well-documented or thought upon in the concept stage.
Stage 4: Building or Developing the Product
In this stage of SDLC the actual development starts and the product is built. The programming code is generated as per DDS during this stage. If the design is performed in a detailed and organized manner, code generation can be accomplished without much hassle. Developers have to follow the coding guidelines defined by their organization and programming tools like compilers, interpreters, debuggers etc are used to generate the code. Different high level programming languages such as C, C++, Pascal, Java, and PHP are used for coding. The programming language is chosen with respect to the type of software being developed.
Stage 6: Deployment in the Market and Maintenance
Once the product is tested and ready to be deployed it is released formally in the appropriate market. Sometime product deployment happens in stages as per the organizations. business strategy. The product may first be released in a limited segment and tested in the real business environment (UAT- User acceptance testing). Then based on the feedback, the product may be released as it is or with suggested enhancements in the targeting market segment. After the product is released in the market, its maintenance is done for the existing customer base.
Stage 2: Defining Requirements
Once the requirement analysis is done the next step is to clearly define and document the product requirements and get them approved from the customer or the market analysts. This is done through .SRS. . Software Requirement Specification document which consists of all the product requirements to be designed and developed during the project life cycle.
Stage 1: Planning and Requirement Analysis
Requirement analysis is the most important and fundamental stage in SDLC. It is performed by the senior members of the team with inputs from the customer, the sales department, market surveys and domain experts in the industry. This information is then used to plan the basic project approach and to conduct product feasibility study in the economical, operational, and technical areas. Planning for the quality assurance requirements and identification of the risks associated with the project is also done in the planning stage. The outcome of the technical feasibility study is to define the various technical approaches that can be followed to implement the project successfully with minimum risks.
What is SDLC?
SDLC is a process followed for a software project, within a software organization. It consists of a detailed plan describing how to develop, maintain, replace and alter or enhance specific software. The life cycle defines a methodology for improving the quality of software and the overall development process.
Stage 3: Designing the product architecture
SRS is the reference for product architects to come out with the best architecture for the product to be developed. Based on the requirements specified in SRS, usually more than one design approach for the product architecture is proposed and documented in a DDS - Design Document Specification. This DDS is reviewed by all the important stakeholders and based on various parameters as risk assessment, product robustness, design modularity , budget and time constraints , the best design approach is selected for the product. A design approach clearly defines all the architectural modules of the product along with its communication and data flow representation with the external and third party modules (if any). The internal design of all the modules of the proposed architecture should be clearly defined with the minutest of the details in DDS.
What is V-model - SDLC?
The V - model is SDLC model where execution of processes happens in a sequential manner in V-shape. It is also known as Verification and Validation model. V - Model is an extension of the waterfall model and is based on association of a testing phase for each corresponding development stage. This means that for every single phase in the development cycle there is a directly associated testing phase. This is a highly disciplined model and next phase starts only after completion of the previous phase.
WaterFall Model Design
The whole process is divided into separate phases - typically the outcome phase acts as the input for the next step
What is the Agile Model?
This is the 7 steps split up so they can do all the planning and all the gathering and show it to the stakeholder so they can approve it. -- divide the work into smaller units or iteration [ so you plan smaller parts and deliver to your customers ] -- smaller deadlines that are given by the customer that you must follow to give them what they want -the itration is the task and as a BA we explain to them what is needed and what needs to be done to our team - when youre getting the requirements the client will tell you the first thing to do and what to get done.
Stage 5: Testing the Product
This stage is usually a subset of all the stages as in the modern SDLC models, the testing activities are mostly involved in all the stages of SDLC. However this stage refers to the testing only stage of the product where products defects are reported, tracked, fixed and retested, until the product reaches the quality standards defined in the SRS.
What is the waterfall model?
it is also refereed to as a linear sequential life cycle model [ each phase must be finish for the next to start ] first SDLC approach
what are the 5 things that all iteration should have?
planning req analysis designing building testing
What are the sequential phases of waterfall model?
• Requirement Gathering and analysis: All possible requirements of the system to be developed are captured in this phase and documented in a requirement specification doc. • System Design: The requirement specifications from first phase are studied in this phase and system design is prepared. System Design helps in specifying hardware and system requirements and also helps in defining overall system architecture. • Implementation: With inputs from system design, the system is first developed in small programs called units, which are integrated in the next phase. Each unit is developed and tested for its functionality which is referred to as Unit Testing. • Integration and Testing: All the units developed in the implementation phase are integrated into a system after testing of each unit. Post integration the entire system is tested for any faults and failures. • Deployment of system: Once the functional and non functional testing is done, the product is deployed in the customer environment or released into the market. • Maintenance: There are some issues which come up in the client environment. To fix those issues patches are released. Also to enhance the product some better versions are released. Maintenance is done to deliver these changes in the customer environment.
When is using the Waterfall SDLC good?
• Requirements are very well documented, clear and fixed. • Product definition is stable. • Technology is understood and is not dynamic. • There are no ambiguous requirements. • Ample resources with required expertise are available to support the product. • The project is short.
What are the 4 most used SDLC?
• Waterfall Model • Iterative Model • V-Model • Agile