A Study of WaterFall, a Software Development Model
According to en.wikipedia.org Waterfall “is a software development model first proposed in 1970 by w.w. Royce, in which development is seen as flowing steadily through the phase of requirements analysis, design, implementation, testing, (validation), integration, and maintenance”. Waterfall method is the first published model of a software development process (1970). The basic principle is that the different processes (Analysis, Design, Coding, and Testing) are done sequentially. Output from one process is input to the next.
Waterfall method advantages like simple, easy to understand and work with. Waterfall creates very detailed intermediate
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A disadvantage of the iterative process is that it implies that evaluation of the product occurs only after coding. This is an expensive proposition. A variation of the iterative process more appropriate to a HCI is the rapid prototyping.
The Spiral Development process encompasses other process models. The iteration of the sub-problem with the highest associated risk must be identified and solved. To solve the problem any type of "normal" development process (Waterfall, Incremental, Prototyping, etc.) might be employed. Which one is suitable all depends on the risks identified. Its disadvantage is that is almost impossible to make initial time and cost estimates.
Agile Process disadvantage is that is a Manifesto, so business people and developers must work together daily throughout the project. In our experience, most clients who outsource a project do not want intense, daily meetings with their vendor
Description of Iterative and Agile Methods
Iterative design is a design methodology-based on a cyclic process of prototyping, testing, analyzing, and refining a work in progress. In iterative design, interaction with the designed system is used as a form of research for informing and evolving a project, as successive versions, or iterations of a design are implemented.
Cost and resource needs are higher for traditional than Agile due to Waterfall’s sequential development phase of all requirements determined in the beginning, software design and finally implementation of master design. The need for all information up front takes substantial time to gather and the sequential design does not allow for project changes as the flow enters into the programming stage. With Agile, costs remain low because there exists an incremental and iterative approach to the project, meaning less time is used to collect all requirements up front, the
The project is Agile, i.e. it can quickly adapt to changes in requirements. Hence, this method has high success rates.
Using the waterfall approach the system developers will be able to focus on one piece of the system and move on each part separately. This will give the design team more time to focus on small sections of the new coding. Moving from one stage to the next means that each step has been checked thoroughly and is completed.
The rigid methods employed by the Waterfall approach makes it easy to manage because the team cannot move onto the next stage if all of the
After having reviewed definitions and perspectives by three author groups, I’m inclined to conclude that waterfall methodology is essentially defined by its insistence upon the completion of product development steps in a sequential manner in order to accommodate a client’s need for a product or tool that will enable their business to be performed in a temporally defined effective (or desired) manner. By utility, for the sake of quickly delivering a product to the satisfaction of its client, a development team who employs the waterfall method may do so because of waterfall’s logical yet rigid structure. Its step-by-step nature promotes an easy to follow guide, though many of the tasks involved in the process of its development are anything but easy. Further, waterfall’s rigid nature seems to reinforce the notion of its logic, if but for the sake of timely product completion and client budget. Due to its methodological rigidity, however, products developed by way of waterfall may tend to be rigid in their own right.
It has been observed that in software development, change is unavoidable and must be accommodated for in the life cycle. A number of alternative process models have been introduced in order to attempt to fix the issues in the Waterfall model. An early modification to the standard Waterfall method introduced prototyping as a feedback and discovery mechanism to identify misunderstandings and omissions early on in the process (Neill, 2004). Other process models attempted to further get rid of the risks of misunderstandings by breaking down projects
SC will compare traditional and various iterative implementations of the SDLC. For example, Braude and Bernstein (2011) state that the popular and mature waterfall process model promotes simple comprehension, project management, and resource distribution of small project development lifecycles. The serial nature of the traditional SDLC leans toward the gathering of all requirements at the beginning of the project whereas the majority of testing occurs at the end of the lifecycle. The waterfall model’s linear design creates disastrous risks for large projects if the project team does not understand the core requirements during the initial phase of the project or the detection of major problems occurs toward the end of the project. On the other hand, a spiral model significantly reduces risks for large projects whereas complexity causes overkill for smaller projects. The project’s physical scope, timeline, budget, and resource determine which the most optimal process model for a project. Table 1.1 displays a comparison chart that SC uses to weigh advantages and disadvantages of traditional SDLC and Agile development methodologies. SC will utilize this chart to determine which development methodology is utilized based on the primary amount of questions answered positively weighed with the clients business case requirements. “Agile software development is a
Since the method was developed for manufacturing and construction projects, it made sense in these industries that a portion of the project was fixed and unchangeable after a phase completed. Imagine the construction of a road, you prep and lay down a foundation then eventually lay down the final asphalt or concrete layer. It wouldn’t make sense to build in the ability to go back and change the foundation after the top layer was set. Obviously, software engineering is very different and therefore requires a much different approach to development. Besides slow turnaround, there were many other criticisms of the waterfall method. Some included redesign, rework, and retesting due to lack of knowledge about requirements when a project began. Also, due to the extremely long lead and delivery times, requirements changed or projects were dropped altogether leaving a company with a half-built loss on the balance sheet. An industry average put the estimated time for any software project using the Waterfall approach at 3 years. This was the environment that enabled a few forward-thinking developers to meet and design a new and better approach.
The traditional development method requires the definition and documentation of a stable set of requirements at the beginning of the project. It was inherited by other projects mainly related to construction which focused on the completion of one phase of production before moving on to the next phase, for example, laying the foundations of a building first and then proceeding with the further stages (Bowes 2014). Similarly, in Waterfall, the requirement gathering and designing work is done upfront before any coding takes place. The basic notion behind the traditional development approaches is that the projects are comparatively less complex, linear and predictable with clearly defined system boundaries which makes it simple to plan and follow without having any room for changes (Spundak 2014). Moreover, traditional development method depicts the requirements document as he key piece of documentation. The gathering of all the requirements, getting a sign off from the customer and then starting with the development of the project gives the project a limit of
Software engineering (SE) is the profession concerned with specifying, designing, developing and maintaining software applications by applying technologies and practices from computer science, project management, and other fields.
It involves four process planning, risk Analysis, engineering and evaluation. It is a mixture of both designing and prototyping. it is a bit similar to waterfall model
The waterfall model consists of five phases such as requirements, Design, implementation, verification and maintenance. The method is a sequential design process where progress is seen as flowing downwards in a steadily manner, each development phase has its own distinct goals. The model is similar to water flowing down a cliff it can only flow in one way and cannot go back up it is the same with waterfall development ,after a development phase is completed it proceeds to the next development phase you cannot go back.
Iterative Process – this process establishes a straightforward implementation of a subcategories of the software requirements and iteratively improves the progressing adaptations until the complete system is implemented. At every iteration, design adjustments are made and new useful abilities are enhanced. The simple idea behind this technique is to cultivate a system through repetitive cycles or iterative and in reduced portions at a time or incremental (TutorialsPoints, 2016).
The Waterfall Model is a sequential design process, often used in software development processes, in which progress is seen as flowing steadily downwards (like a waterfall) through the
One of the main scenarios is the implementation of the prototype model into a full-fledged working environment, which is the final product or software.