What is SDLC Waterfall Model? In this model, the software development activity is divided into different phases and each phase consists of series of tasks and has different objectives. Waterfall model is the pioneer of the SDLC processes. In fact it was the first model which was widely used in the software industry. It is divided into phases and output of one phase becomes input of the next phase.

It is mandatory for a phase to be completed before the next phase starts. In short, there is no overlapping in Waterfall model. In waterfall, development of one phase starts only when the previous phase is complete. Because of this nature, each phase of waterfall model is quite precise well defined. Since the phase’s falls from higher level to lower level, like a water fall, It’s named as waterfall model. Pictorial representation of waterfall model: The activities involved in different phases are as follows: S. No. Phase. Activities Performed.

Deliverables. 1Requirement Analysis. Excel Month Serial Number To Text there. Capture all the requirements. Do brainstorming and walkthrough to understand the requirements. Do the requirements feasibility test to ensure that the requirements are testable or not.

Software prototyping is the activity of creating prototypes of software applications, i.e., incomplete versions of the software program being developed. Study material for Foundation level, Premium & Free for ISTQB and ASTQB Exam, Certification questions, answers, software testing tutorials and more. What is SDLC Waterfall Model? Introduction: Waterfall model is an example of Sequential model. In this model, the software development activity is divided into. The spiral model, also known as the spiral lifecycle model, is a systems development method (SDM) used in information technology (IT). This model of development.

RUD ( Requirements Understanding Document)2. System Design. 1. As per the requirements, create the design. Capture the hardware / software requirements. Document the designs. HLD ( High Level Design document)LLD (Low level design document)3. Implementation. 1.

As per the design create the programes / code. Integrate the codes for the next phase. Unit testing of the code.

Programs. Unit test cases and results. System Testing. 1. Integrate the unit tested code and test it to make sure if it works as expected. Perform all the testing activities (Functional and non functional) to make sure that the system meets the requirements. In case of any anomaly, report it. Track your progress on testing through tools like traceability metrics, ALM5. Report your testing activities.

Test cases. Test reports. Defect reports. Updated matrices. System Deployment. Make sure that the environment is up. Make sure that there are no sev 1 defects open. Make sure that the test exit criteria are met. Deploy the application in the respective environment.

Perform a sanity check in the environment after the application is deployed to ensure the application does not break. User Manual. Environment definition / specification. System maintenance. Make sure that the application is up and running in the respective environment.

Incase user encounters and defect, make sure to note and fix the issues faced. Incase any issue is fixed; the updated code is deployed in the environment. The application is always enhanced to incorporate more features, update the environment with the latest features.

User Manual. List of production tickets. List of new features implemented. SDLC Waterfall model is used when.

Requirements are stable and not changed frequently. Application is small. There is no requirement which is not understood or not very clear. The environment is stable. The tools and technology used is stable and is not dynamic.

Resources are well trained and are available. Pros and Cons of waterfall model: Advantages of using Waterfall model are as follows: Simple and easy to understand and use. For smaller projects, waterfall model works well and yield the appropriate results. Since the phases are rigid and precise, one phase is done one at a time , it is easy to maintain.

The entry and exit criteria are well defined, so it easy and systematic to proceed with quality. Results are well documented. Disadvantages of using Waterfall model: Cannot adopt the changes in requirements. It becomes very difficult to move back to the phase. For example, if the application has now moved to testing stage and there is a change in requirement, It becomes difficult to go back and change it. Delivery of the final product is late as there is no prototype which is demonstrated intermediately. For bigger and complex projects, this model is not good as risk factor is higher.

Not suitable for the projects where requirements are changed frequently. Does not work for long and ongoing projects.

Since the testing is done at later stage, it does not allow identifying the challenges and risks in the earlier phase so the risk mitigation strategy is difficult to prepare. Conclusion: In waterfall model it is very important to take the sign off for the deliverables of each phase. As of today most of the projects are moving with Agile and Prototype models, Waterfall model still holds good for smaller projects. If requirements are straightforward and testable, Waterfall model will yield the best results.

Software prototyping - Wikipedia. Software prototyping is the activity of creating prototypes of software applications, i. It is an activity that can occur in software development and is comparable to prototyping as known from other fields, such as mechanical engineering or manufacturing. A prototype typically simulates only a few aspects of, and may be completely different from, the final product. Prototyping has several benefits: the software designer and implementer can get valuable feedback from the users early in the project.

The client and the contractor can compare if the software made matches the software specification, according to which the software program is built. It also allows the software engineer some insight into the accuracy of initial project estimates and whether the deadlines and milestones proposed can be successfully met. The degree of completeness and the techniques used in prototyping have been in development and debate since its proposal in the early 1.

Prototyping can also be used by end users to describe and prove requirements that have not been considered, and that can be a key factor in the commercial relationship between developers and their clients. Prototyping can also avoid the great expense and difficulty of having to change a finished software product. The practice of prototyping is one of the points Frederick P. Brooks makes in his 1. The Mythical Man- Month and his 1. The NYU Ada/ED system was the first validated Ada implementation, certified on April 1. Details, such as security, can typically be ignored.

Develop initial prototype. The initial prototype is developed that includes only user interfaces.

Negotiation about what is within the scope of the contract/product may be necessary. If changes are introduced then a repeat of steps #3 and #4 may be needed. Dimensions of prototypes.

It provides a broad view of an entire system or subsystem, focusing on user interaction more than low- level system functionality, such as database access. Horizontal prototypes are useful for: Confirmation of user interface requirements and system scope,Demonstration version of the system to obtain buy- in from the business,Develop preliminary estimates of development time, cost and effort. Vertical prototype. It is useful for obtaining detailed requirements for a given function, with the following benefits: Refinement database design,Obtain information on data volumes and system interface needs, for network sizing and performance engineering,Clarify complex requirements by drilling down to actual system functionality.

Types of prototyping. However, all of the methods are in some way based on two major forms of prototyping: throwaway prototyping and evolutionary prototyping. Throwaway prototyping. Throwaway or rapid prototyping refers to the creation of a model that will eventually be discarded rather than becoming part of the final delivered software. After preliminary requirements gathering is accomplished, a simple working model of the system is constructed to visually show the users what their requirements may look like when they are implemented into a finished system.

It is also a rapid prototyping. Rapid prototyping involves creating a working model of various parts of the system at a very early stage, after a relatively short investigation. The method used in building it is usually quite informal, the most important factor being the speed with which the model is provided. The model then becomes the starting point from which users can re- examine their expectations and clarify their requirements.

When this goal has been achieved, the prototype model is 'thrown away', and the system is formally developed based on the identified requirements. If the users can get quick feedback on their requirements, they may be able to refine them early in the development of the software. Making changes early in the development lifecycle is extremely cost effective since there is nothing at that point to redo. If a project is changed after a considerable amount of work has been done then small changes could require large efforts to implement since software systems have many dependencies.

Speed is crucial in implementing a throwaway prototype, since with a limited budget of time and money little can be expended on a prototype that will be discarded. Another strength of throwaway prototyping is its ability to construct interfaces that the users can test.

The user interface is what the user sees as the system, and by seeing it in front of them, it is much easier to grasp how the system will function. Requirements can be identified, simulated, and tested far more quickly and cheaply when issues of evolvability, maintainability, and software structure are ignored.

This, in turn, leads to the accurate specification of requirements, and the subsequent construction of a valid and usable system from the user's perspective, via conventional software development models. One method of creating a low fidelity throwaway prototype is paper prototyping. The prototype is implemented using paper and pencil, and thus mimics the function of the actual product, but does not look at all like it.

Another method to easily build high fidelity throwaway prototypes is to use a GUI Builder and create a click dummy, a prototype that looks like the goal system, but does not provide any functionality. The usage of storyboards, animatics or drawings is not exactly the same as throwaway prototyping, but certainly falls within the same family. These are non- functional implementations but show how the system will look.

Summary: In this approach the prototype is constructed with the idea that it will be discarded and the final system will be built from scratch. The steps in this approach are: Write preliminary requirements.

Design the prototype. User experiences/uses the prototype, specifies new requirements. Repeat if necessary. Write the final requirements. Evolutionary prototyping. The main goal when using evolutionary prototyping is to build a very robust prototype in a structured manner and constantly refine it.

The reason for this approach is that the evolutionary prototype, when built, forms the heart of the new system, and the improvements and further requirements will then be built. When developing a system using evolutionary prototyping, the system is continually refined and rebuilt. A product is never . We make assumptions about the way business will be conducted and the technology base on which the business will be implemented. A plan is enacted to develop the capability, and, sooner or later, something resembling the envisioned system is delivered.

Although they may not have all the features the users have planned, they may be used on an interim basis until the final system is delivered. The partial system is sent to customer sites. As users work with the system, they detect opportunities for new features and give requests for these features to developers.

Developers then take these enhancement requests along with their own and use sound configuration- management practices to change the software- requirements specification, update the design, recode and retest. At the end, the separate prototypes are merged in an overall design. By the help of incremental prototyping the time gap between user and software developer is reduced. Extreme prototyping.

Basically, it breaks down web development into three phases, each one based on the preceding one. The first phase is a static prototype that consists mainly of HTML pages. In the second phase, the screens are programmed and fully functional using a simulated services layer. In the third phase, the services are implemented. The process is called extreme prototyping to draw attention to the second phase of the process, where a fully functional UI is developed with very little regard to the services other than their contract. Advantages of prototyping.