• 瀑布模型有以下优点 1）为项目提供了按阶段划分的检瀑布模型。 2）当前一阶段完成后，您只需要去关注后续阶段。 3）可在迭代模型中应用瀑布模型。 增量迭代应用于瀑布模型。迭代1解决最大的问题。每次迭代产生一个可...
瀑布模型有以下优点
1）为项目提供了按阶段划分的检瀑布模型。
2）当前一阶段完成后，您只需要去关注后续阶段。
3）可在迭代模型中应用瀑布模型。
增量迭代应用于瀑布模型。迭代1解决最大的问题。每次迭代产生一个可运行的版本,同时增加更多的功能。每次迭代必须经过质量和集成测试。
4）它提供了一个模板，这个模板使得分析、设计、编码、测试和支持的方法可以在该模板下有一个共同的指导。
瀑布模型有以下缺点
1）各个阶段的划分完全固定，阶段之间产生大量的文档，极大地增加了工作量。
2）由于开发模型是线性的，用户只有等到整个过程的末期才能见到开发成果，从而增加了开发风险。
3）通过过多的强制完成日期和里程碑来跟踪各个项目阶段。
4）瀑布模型的突出缺点是不适应用户需求的变化。


展开全文
• h模型,x模型,瀑布模型The classical waterfall model is one of the oldest software lifecycle models that were developed to provide a systematic approach to the developers for developing any software....
h模型,x模型,瀑布模型The classical waterfall model is one of the oldest software lifecycle models that were developed to provide a systematic approach to the developers for developing any software. It can be said that all the other software lifecycle models were derived from this classical waterfall model just by adding some additional features and omitting some.
经典瀑布模型是最古老的软件生命周期模型之一，旨在为开发人员提供系统的方法来开发任何软件。 可以说，所有其他软件生命周期模型都是通过添加一些附加功能并省略一些功能而从此经典瀑布模型派生而来的。
The name waterfall itself defines the characteristics of the model. As a waterfall flows only downwards and cannot flow back, in the same way, the phases in the waterfall model are followed one after the other in the same sequence as mentioned. And after completing a phase and entering into another phase, we cannot go back to the previous phase.
瀑布本身定义了模型的特征。 由于瀑布仅向下流动而不能倒流，因此，以相同的方式， 瀑布模型中的各个阶段按照上述相同顺序依次进行。 在完成一个阶段并进入另一个阶段之后，我们无法返回上一个阶段。
The different phases that are included in the classical waterfall model are:
经典瀑布模型包含的不同阶段是：
Feasibility study 可行性研究 Requirement analysis and specification 需求分析和规范 Design 设计 Coding and unit testing 编码和单元测试 Integration and system testing 集成和系统测试 Maintenance 保养 An overview of these phases of the classical waterfall model can be made from the following diagram:
可以从下图概述经典瀑布模型的这些阶段 ：

Each of the phases of this model is executed one after the other. You cannot break the flow and you cannot go back to the previous phase as stated earlier.
此模型的每个阶段都一个接一个地执行。 您不能中断流程，也不能返回到前面所述的上一个阶段。
This means that if you are in the design phase, then you cannot conduct the requirement analysis and specification study for the software. That has already been earlier and now there is no scope left for making any kind of changes in the software requirements according to the classical waterfall model. All that needs to be completed before getting onto the design phase.
这意味着，如果您处于设计阶段，则无法进行软件的需求分析和规格研究。 那已经很早了，现在没有根据经典瀑布模型对软件需求进行任何形式更改的余地。 在进入设计阶段之前，所有需要完成的工作。
We can also relate this model with our many days to day activities that must be performed in a particular order. This can be well understood with the following example:
我们还可以将此模型与必须按特定顺序执行的许多日常活动联系起来。 通过以下示例可以很好地理解这一点：
Suppose you want to make a dish in a couple of hours. Then your feasibility phase and requirement analysis phase starts in the initial phase of making the dish itself. First, you need to decide what you will be making. That is your feasibility study. Now let’s say your requirements include chopping board, vegetables, flour, spices, oil, etc. You need to list them up before going to the market itself. That’s your requirements and specification phase. Now you prepare everything up and assemble in the utensil. That’s the designing part. And the cooking and tasting part becomes your coding and testing part. Final plating of the dish in the integration part and then you finally present your dish in front of the customers. After that, adding any sort of extra spices or re-heating the dish in some cases can be thought as of your maintenance part.
假设您要在几个小时内做一道菜。 然后，您的可行性阶段和需求分析阶段将从制作盘子本身的初始阶段开始。 首先，您需要决定要做什么。 那是你的可行性研究。 现在，假设您的需求包括砧板，蔬菜，面粉，香料，油等。您需要先列出它们，然后才能进入市场。 那就是您的需求和规范阶段。 现在您准备好所有东西并组装在器具中。 那是设计的部分。 烹饪和品尝部分成为您的编码和测试部分。 在集成部分对盘子进行最后的电镀，然后您最终将盘子展示给客户。 之后，在您的维护部分，可以考虑添加任何种类的额外香料或在某些情况下重新加热餐具。
So you see, if you skip any of the phase-in between or break the flow of these phases, then you will not be able to present your final dish in front of the customers on time.

因此，您会看到，如果您跳过这些阶段之间的任何阶段或中断这些阶段的流程，那么您将无法按时在客户面前展示您的最终菜肴。
翻译自: https://www.includehelp.com/basics/the-classical-waterfall-model.aspxh模型,x模型,瀑布模型
展开全文
• h模型,x模型,瀑布模型What is Waterfall Model? 什么是瀑布模型？ Waterfall model is the classic Software Development Life Cycle method practiced in software development process. As the name "waterf...
h模型,x模型,瀑布模型What is Waterfall Model? 什么是瀑布模型？

Waterfall model is the classic Software Development Life Cycle method practiced in software development process. As the name "waterfall" describes, this development is flowing downwards steadily like waterfall, i.e., proceeds from one phase to another phase. This process is a sequential process or a linear process where in the output of one phase is input of another phase. So previous phase becomes important to be completed before we move to next phase. 瀑布模型是在软件开发过程中实践的经典软件开发生命周期方法。 正如“瀑布”一词所描述的，这种发展像瀑布一样稳定地向下流动，即从一个阶段发展到另一阶段。 该过程是顺序过程或线性过程，其中在一个相的输出中是另一相的输入。 因此，在进入下一阶段之前，必须完成上一阶段的工作。

Here is the diagram that describes all phases of waterfall model. 这是描述瀑布模型所有阶段的图。

Requirement Gathering and Analysis Phase: This is the first phase where requirements to produce a product are gathered and analyzed. This is the phase which involves customer. All information about the entire process are identified to be designed and delivered here. 需求收集和分析阶段：这是收集和分析生产产品的需求的第一个阶段。 这是涉及客户的阶段。 有关整个过程的所有信息都将在此处进行设计和交付。

Design Phase: The requirements from the earlier phase are documented and converted into technical design. Like what hardware, system software, technology, language are used etc. are specified. 设计阶段：记录早期阶段的需求并将其转换为技术设计。 就像指定了什么硬件，系统软件，技术，语言等。

Implement Phase:  Output from Design phase are used and implemented to achieve the goal. They are split in program units. These program units are developed independently and functionally tested. This is called Unit Testing. 实施阶段：设计阶段的输出用于实现目标。 它们分为程序单元。 这些程序单元是独立开发并经过功能测试的。 这称为单元测试。

Test Phase: Here all program units which are developed in implement phase are integrated and tested together to see end product has all desired functionalities required. 测试阶段：在这里，将在实施阶段开发的所有程序单元进行集成和测试，以查看最终产品具有所需的所有所需功能。

Deploy Phase: Once Test phase is successfully completed, it is deployed in customer environments and product is released. 部署阶段：成功完成测试阶段后，便会在客户环境中部署它并发布产品。

Maintenance Phase: If any changes are required in client environments then they are upgraded and released as patches to fix any issues that come up after deployment. 维护阶段：如果客户端环境中需要任何更改，则将它们升级并作为补丁发布，以解决部署后出现的所有问题。

Waterfall Model Pros: 瀑布模型的优点：

1. Simple, easy to understand and use. 1.简单，易于理解和使用。

2. All phases are clearly documented and understood well in the beginning of software development life cycle 2.在软件开发生命周期的开始阶段，所有阶段都被清楚地记录和很好地理解

3. Since each phase has to be completed before we move to next phase issues will be identified and corrected in initial phase itself. 3.由于在进入下一阶段之前必须完成每个阶段，因此将在初始阶段中识别并纠正问题。

4. Since requirements are well understood and analyzed in beginning of project customer involvement in later phases is minimized. 4.由于在项目开始时就可以很好地理解和分析需求，因此可以将客户在后期阶段的参与降至最低。

5. High Visibility - The output of each stage gives more visibility on where we stand on progress of development. 5.高度可见性-每个阶段的输出使我们对开发进度的立场更具可见性。

6. This approach has control over deadline as work is distributed to teams in each stage. 6.这种方法可以控制截止日期，因为工作分配到每个阶段的团队。

Waterfall Model cons: 瀑布模型的缺点：

1. Not Flexible. Because this is a rigid model, Requirements cannot be changed throughout the cycle. 1.不灵活。 由于这是一个严格的模型，因此无法在整个周期内更改需求。

2. With rapid change in technology day by day we cannot have control to change the hardware and system requirements. Since system and hardware requirements are set up by customers in the beginning. 2.随着技术的日新月异，我们无法控制更改硬件和系统要求。 由于系统和硬件要求是一开始由客户设置的。

3. Small change in one phase leads to big change in each phase, as these phases are dependent on one another and eventually more time is consumed 3.一个阶段的小变化会导致每个阶段的大变化，因为这些阶段相互依赖，最终会消耗更多的时间

4. If assumptions about implementations are wrong then estimated time for each phases exceeds and fails to meet deadline. 4.如果关于实施的假设是错误的，则每个阶段的估计时间将超过且未能达到期限。

5. Resource idle time might increase as they have to be idle until previous stage is completely done. Therefore it is expensive. 5.资源闲置时间可能会增加，因为它们必须闲置，直到上一步完成为止。 因此，它是昂贵的。

6. Difficult to see the progress within phases. 6.难以分阶段看到进度。

7. Challenges, major issues, bottlenecks are identified in last stages in integration testing. So no visibility of these in the beginning and high risk. 7.在集成测试的最后阶段确定了挑战，主要问题和瓶颈。 因此，这些在开始时就没有可见性，而且风险很高。

8. Product/Software deliverables are at the end of cycle. 8.产品/软件可交付成果在周期结束时。

When to Choose waterfall Approach? 什么时候选择瀑布方式？

1. Choose this approach for small projects. 1.对于小型项目，请选择此方法。

2. This method is best suited for products which has stable definition. 2.此方法最适合分辨率稳定的产品。

3. This is best approach when the requirements are very well known and are not fluctuating. 3.当需求众所周知并且没有波动时，这是最佳方法。

4. Use this approach when Process has clear objectives and solutions. 4.当流程具有明确的目标和解决方案时，请使用此方法。

5. Use when you want to conserve the resources
5.当您想节省资源时使用
翻译自: https://www.experts-exchange.com/articles/17441/Waterfall-Model-pros-and-cons.htmlh模型,x模型,瀑布模型
展开全文
• 典型瀑布模型四个阶段The different phases that are included in the classical waterfall model are: 经典瀑布模型包含的不同阶段是： Feasibility study 可行性研究 Requirement analysis and specification ...
典型瀑布模型四个阶段The different phases that are included in the classical waterfall model are:
经典瀑布模型包含的不同阶段是：
Feasibility study 可行性研究 Requirement analysis and specification 需求分析和规范 Design 设计 Coding and unit testing 编码和单元测试 Integration and system testing 集成和系统测试 Maintenance 保养 Now, let us explain the different processes that are followed in each of these phases while the entire software development process.
现在，让我们解释整个软件开发过程中每个阶段所遵循的不同过程。
1)可行性研究 (1) Feasibility study)
In the feasibility study, we try to study the software in terms of technical and business aspects, to determine whether it would be beneficial for the company (or the organization) to build the particular software, whether the consumers will be satisfied through it or not and how much profit the software will be able to provide us.
在可行性研究中，我们尝试从技术和业务方面进行研究，以确定对公司(或组织)而言，构建特定软件是否有利，消费者是否会满意它？以及该软件能够为我们提供多少利润。
The feasibility study takes place as follows:
可行性研究如下：
A rough understanding of the project by the team leaders and heads from the client-side. 团队负责人和客户负责人对项目有一个大概的了解。 Analyzing every aspect of the client's views and reaching a state overall understanding of the project is made. 分析客户观点的各个方面，并达到对项目总体状态的理解。 Picking up the best solution. 选择最好的解决方案。  2)分析和规格 (2) Analysis and specification)
Here, all the requirements of the software are analyzed and documented properly. This is a very important phase because, in the classical waterfall model, each requirement must be documented in this phase itself because we cannot add or modify any of them in the later phases of development. This phase mainly involves two things:
在此，将对软件的所有要求进行适当的分析和记录。 这是非常重要的阶段，因为在经典瀑布模型中，每个需求都必须在该阶段本身中记录下来，因为我们不能在开发的后期阶段添加或修改其中的任何一个。 此阶段主要涉及两件事：
Requirements gathering 需求收集 Requirements specification 要求规范  3)设计 (3) Design)
In the design phase, a blueprint of the entire software is created. How the software must appear as a final product is decided in the designing phase itself. Hence, the design of the software gives an overview of the software to the developers so that they can work on that accordingly. This is done so that all the requirements are transformed into a structural manner which now makes it easier for the developers to implement.
在设计阶段，将创建整个软件的蓝图。 在最终设计阶段，将决定软件作为最终产品的外观。 因此，软件的设计向开发人员提供了软件的概述，以便他们可以相应地进行工作。 这样做是为了将所有需求转换为结构化方式，这现在使开发人员更容易实现。
The designing team can follow different approaches like the traditional approach, the procedural approach, the object-oriented approach, etc.
设计团队可以遵循不同的方法，例如传统方法，过程方法，面向对象方法等。
4)编码和单元测试 (4) Coding and unit testing)
In the coding phase, the developers code the program in any suitable programming language. While developing any feature of the software, the developers also have to test the feature on their level to check whether it is working fine or not. Therefore, the testing involved in this phase is termed as unit testing.
在编码阶段，开发人员可以使用任何合适的编程语言对程序进行编码。 在开发该软件的任何功能时，开发人员还必须在其级别上测试该功能，以检查该功能是否正常运行。 因此，此阶段涉及的测试称为单元测试。
5)集成与系统测试 (5) Integration and system testing)
Different developers work on different subprograms. Now, all these subprograms need to be integrated to get our final software. Also, when the subprograms (or modules) are integrated, then they may function in a different manner which is not expected. SO, it is the job of the tester now to check the software for each functionality. There are three testing rounds that software must undergo before the deployment of the final software. They are:
不同的开发人员从事不同的子程序。 现在，所有这些子程序都需要集成以获得最终软件。 同样，当子程序(或模块)集成在一起时，它们可能会以不同的方式起作用，这是无法预期的。 因此，现在测试人员的工作就是检查每种功能的软件。 在部署最终软件之前，软件必须经过三轮测试。 他们是：
Alpha testing 阿尔法测试 Beta testing Beta测试 Acceptance testing 验收测试  6)保养 (6) Maintenance)
After the final testing, the software may require some maintenance before getting deployed. Even after getting deployed, there can occur certain problems that may occur in the software with the use. All these are also handled and maintained in the maintenance phase of the software lifecycle.

在最终测试之后，该软件可能需要进行一些维护才能部署。 即使在部署之后，使用中的软件也可能会出现某些问题。 所有这些都在软件生命周期的维护阶段进行处理和维护。
翻译自: https://www.includehelp.com/basics/the-different-phases-of-the-classical-waterfall-model.aspx典型瀑布模型四个阶段
展开全文
• 软件生命周期瀑布模型Hello guys, so today we would be looking at one of the widely known and the simplest software life cycle model i.e. waterfall models, as the name suggests the reason for naming ...
• 瀑布模型（Waterfall Model）**瀑布模型（Waterfall Model） 是一个软件生命周期模型，开发过程是通过设计一系列阶段顺序展开的，从系统需求分析开始直到产品发布和维护，项目开发进程从一个阶段“流动”到下一个...
• 一、瀑布模型 1.1什么是瀑布模型 1.2特点 1.3优缺点 1.4客户需求 二、快速原型模型 2.1什么是快速原型模型 2.2优缺点 2.3快速原型模型的思想产生、原理及运用方式 2.4类型 2.5开发步骤 三、增量模型 3.1...
• Content瀑布模型(生命周期模型)原型模型增量模型 综合瀑布模型与原型模型螺旋模型喷泉模型RUP过程模型敏捷过程 详细内容 参考链接 1.瀑布模型、快速原型模型、增量模型、螺旋模型 优缺点及其适用范围. 2.软件工程 ...
• 软件研发模型-瀑布模型瀑布模型1970年Winston Royce温斯顿罗伊斯提出了著名的瀑布模型到了20世纪80年代早期它成为唯一被广泛采用的软件开发模型瀑布模型将软件生命周期划分为计划需求分析设计编码测试和运行维护这6...
• 对比十几种软件开发模型 瀑布模型 演化模型 螺旋模型 喷泉模型 快速原型模型 智能模型 混合模型 敏捷开发 极限编程XP
• 瀑布模型1）软件概念阶段 用户需求2）需求分析 软件需求3）架构设计 架构文档4）详细设计 模型设计5）编码阶段 代码文档6）测试阶段瀑布模型的特点是在每个阶段的工作都清晰详尽，容易预估风险和开发成本，每个阶段...
• 在前期需求明确的情况下尽量采用瀑布模型或改进型的瀑布模型，在用户无信息系统使用经验分析人员技能不足的情况下一定要借助原型。在不确定性因素很多，难以提前估计和计划的情况下尽量采用迭代和螺旋模型。在技术...
• 瀑布模型2. 螺旋模型3. 迭代模型4. 增量模型5. 敏捷模型 0. 软件的生命周期   软件的生命周期是指从软件产品的设想开始到软件不在使用而结束的时间。   软件的生命周期分为6个阶段，即需求分析、计划、设计、...
• **瀑布模型，原型模型，增量模型，螺旋模型，喷泉模型**，在实际项目中，通常数个模型方法共同使用
• 瀑布模型，适用于结构化的软件项目，是面向过程的软件测试模型。 具体的流程如图所示： 项目计划：投入多少人，时间进度如何安排； 需求分析：产品经理输出需求文档，项目组的人员再对这份文档进行分析，对需求...

...