More about Rapid Release Methodology..............

The Rapid Release Model
The Internet enables software companies to adopt a new software development model, the Rapid Release Model. In this model, once a product is released, a new version is released on the Internet every 90 days. Each 90-day update includes both bug fixes and new features. The pace of development is no different than in the 18-month development cycle, but new features are released to customers as soon as they are ready. During an 18-month period the customer receives six updates that collectively equal or exceed what he traditionally would have received from a single, monolithic update.
Benefits to Customers
Customers benefit from the rapid release model in three ways:
(1) Higher quality
During a 90-day development cycle, new features are implemented during the first 60 days and are tested and debugged during the last 30 days. Any bugs found during testing are easier to fix because the code is still fresh in the developer's mind. During an 18-month cycle, the code in question could be more than a year old. Also, in the Rapid Release Model, the pressure to release features before they are ready is greatly reduced because the next release is already scheduled in 90 days.

The Rapid Release Model does not increase the pace of software development, but it does increase the pace of releases.

(2) Better service
Releasing an update every 90 days enables the software developer to be more responsive to the needs of its customers. For example, when an update to the operating system ships, customers know that an updated version of their software that supports the new OS will be shipping within 90 days. In addition, software companies can plan releases around major OS updates to further prevent customers from having to wait.
(3) Lower price
The Rapid Release Model is more cost effective for the software developer because it no longer maintains the old version of their product while working on a new version. In the Rapid Release Model, old versions are not maintained; they are replaced by an update that contains both bug fixes and new features. The lower cost of development is a benefit that some software companies will choose to pass on to their customers.
Benefits to Developers
Software developers also benefit from the Rapid Release Model in three ways:
(1) Enhanced competitiveness
Software companies that employ the Rapid Release Model can respond very quickly to changing market conditions, demonstrating greater market agility, the ability to be responsive to customer requirements. This makes companies on longer development cycles struggle to keep up.
(2) Reduced risk
Large, monolithic releases can be very risky because 18 months is an enormous period of time in the technology business. Market conditions today are nothing like they were two years ago. Release dates for large updates are often delayed because customer requirements change during the development cycle as new features must be added to an already complex development project. Releasing every 90 days minimizes risk by reducing the amount of time between planning a product and releasing it.
(3) More marketing opportunities
Before the Internet, marketing software required long-range planning around print advertising and magazine editorial calendars. Today, however, most software marketing takes place online, where software updates are covered on websites and in blogs where content is updated on a daily basis. In the Internet marketing game, each new release provides a fresh opportunity to grab a fleeting moment of coverage and online advertising can be focused on the benefits of each new release.

The Rapid Release Model provides more opportunities for a software product to be mentioned by the media as interesting new product releases are made available more frequently.

The Rapid Release Business Model
One challenge with the Rapid Release Model is finding the right way to sell frequent releases to customers. Clearly it would be problematic to ask a customer to purchase an update every three months. Customers would consider this onerous and corporate purchasing departments would be resistant to authorizing frequent update orders. In addition, determining the correct pricing for each small upgrade would be challenging. For these reasons, the most effective way to package and sell rapid updates is through a software maintenance model, where the customer purchases all of the updates released during a 12-month period. This enables the customer to conduct just one transaction per year while receiving an update every 90 days.

Customers do not want to purchase a software upgrade every 90 days.

The customer's concern with this model is whether the developer will stay on schedule and release an update every 90 days. The solution to this problem is to include six months of updates with every new purchase to demonstrate a commitment to the Rapid Release Model before asking the customer to purchase 12 months of updates.
By the time the six months of updates have ended the customer has received two "free" updates and is convinced of the software developer's ability to rapidly update its product.
Conclusion
The traditional 18-month development cycle is a vestige of pre-Internet sales models. Although some commercial software, such as games, require long development cycles with no updates, most software companies and their customers would benefit from a move towards shorter, faster development cycles.
Consumer benefits of this model include higher quality, better service and lower prices. Developer benefits include greater competitiveness, reduced risk and more marketing opportunities.
Developers who do remain on traditional 18-month schedules will appear slow and unresponsive when compared to their more agile competitors who adopt the Rapid Release Model.

More about Extreme Testing or Test Driven Methodology

Extreme Programming

In Extreme Programming, rather than designing whole of the system at the start of the project, the preliminary design work is reduced to solving the simple tasks that have already been identified.
The developers communicate directly with customers and other developers to understand the initial requirements. They start with a very simple task and then get feedback by testing their software as soon as it is developed. The system is delivered to the customers as soon as possible, and the requirements are refined or added based on customer feedback. In this way, requirements evolve over a period of time, and developers are able to respond quickly to changes.
The real design effort occurs when the developers write the code to fulfill the specific engineering task. The engineering task is a part of a greater user story (which is similar to a use case). The user story concerns itself with how the overall system solves a particular problem. It represents a part of the functionality of the overall system. A group of user stories is capable of describing the system as a whole. The developers refactor the previous code iteration to establish the design needed to implement the functionality.
During the Extreme Programming development life cycle, developers usually work in pairs. One developer writes the code for a particular feature, and the second developer reviews the code to ensure that it uses simple solutions and adheres to best design principles and coding practices.
Discussion of the core practices of Extreme Programming is beyond the scope of this chapter. For more information, see the links referred to in "More Information" later in this section.
Test-driven development, which is one of the core practices in Extreme Programming, is discussed in greater detail later in this chapter.

When to Use Extreme Programming

Extreme Programming is useful in the following situations:

• When the customer does not have a clear understanding of the details of the new system. The developers interact continuously with the customer, delivering small pieces of the application to the customer for feedback, and taking corrective action as necessary.
• When the technology used to develop the system is new compared to other technologies. Frequent test cycles in Extreme Programming mitigate the risk of incompatibility with other existing systems.
• When you can afford to create automated unit and functional tests. In some situations, you may need to change the system design so that each module can be tested in isolation using automated unit tests.
• When the team size is not very large (usually 2 to 12 people). Extreme Programming is successful in part because it requires close team interaction and working in pairs. A large team would have difficulty in communicating efficiently at a fast pace. However, large teams have used Extreme Programming successfully.

More Information

For more information about the core practices in Extreme Programming, see the following resources:

• "What Is Extreme Programming?" at http://xprogramming.com/xpmag/whatisxp
• "Extreme Programming: A Gentle Introduction" at http://www.extremeprogramming.org/

More about Agile Methodology

Agile Methodology

Most software development life cycle methodologies are either iterative or follow a sequential model (as the waterfall model does). As software development becomes more complex, these models cannot efficiently adapt to the continuous and numerous changes that occur. Agile methodology was developed to respond to changes quickly and smoothly. Although the iterative methodologies tend to remove the disadvantage of sequential models, they still are based on the traditional waterfall approach. Agile methodology is a collection of values, principles, and practices that incorporates iterative development, test, and feedback into a new style of development. For an overview of agile methodology, see the Agile Modeling site at http://www.agilemodeling.com/.
The key differences between agile and traditional methodologies are as follows:

• Development is incremental rather than sequential. Software is developed in incremental, rapid cycles. This results in small, incremental releases, with each release building on previous functionality. Each release is thoroughly tested, which ensures that all issues are addressed in the next iteration.
• People and interactions are emphasized, rather than processes and tools. Customers, developers, and testers constantly interact with each other. This interaction ensures that the tester is aware of the requirements for the features being developed during a particular iteration and can easily identify any discrepancy between the system and the requirements.
• Working software is the priority rather than detailed documentation. Agile methodologies rely on face-to-face communication and collaboration, with people working in pairs. Because of the extensive communication with customers and among team members, the project does not need a comprehensive requirements document.
• Customer collaboration is used, rather than contract negotiation. All agile projects include customers as a part of the team. When developers have questions about a requirement, they immediately get clarification from customers.
• Responding to change is emphasized, rather than extensive planning. Extreme Programming does not preclude planning your project. However, it suggests changing the plan to accommodate any changes in assumptions for the plan, rather than stubbornly trying to follow the original plan.

Agile methodology has various derivate approaches, such as Extreme Programming, Dynamic Systems Development Method (DSDM), and SCRUM. Extreme Programming is one of the most widely used approaches.

More about Prototyping methodology ....

Prototyping Model

The prototyping model assumes that you do not have clear requirements at the beginning of the project. Often, customers have a vague idea of the requirements in the form of objectives that they want the system to address. With the prototyping model, you build a simplified version of the system and seek feedback from the parties who have a stake in the project. The next iteration incorporates the feedback and improves on the requirements specification. The prototypes that are built during the iterations can be any of the following:

• A simple user interface without any actual data processing logic
• A few subsystems with functionality that is partially or completely implemented
• Existing components that demonstrate the functionality that will be incorporated into the system

The prototyping model consists of the following steps.

1. Capture requirements. This step involves collecting the requirements over a period of time as they become available.
2. Design the system. After capturing the requirements, a new design is made or an existing one is modified to address the new requirements.
3. Create or modify the prototype. A prototype is created or an existing prototype is modified based on the design from the previous step.
4. Assess based on feedback. The prototype is sent to the stakeholders for review. Based on their feedback, an impact analysis is conducted for the requirements, the design, and the prototype. The role of testing at this step is to ensure that customer feedback is incorporated in the next version of the prototype.
5. Refine the prototype. The prototype is refined based on the impact analysis conducted in the previous step.
6. Implement the system. After the requirements are understood, the system is rewritten either from scratch or by reusing the prototypes. The testing effort consists of the following:
   • Ensuring that the system meets the refined requirements
   • Code review
   • Unit testing
   • System testing

The main advantage of the prototyping model is that it allows you to start with requirements that are not clearly defined.
The main disadvantage of the prototyping model is that it can lead to poorly designed systems. The prototypes are usually built without regard to how they might be used later, so attempts to reuse them may result in inefficient systems. This model emphasizes refining the requirements based on customer feedback, rather than ensuring a better product through quick change based on test feedback.

More about Incremental or Iterative methodology

Incremental or Iterative Development

The incremental, or iterative, development model breaks the project into small parts. Each part is subjected to multiple iterations of the waterfall model. At the end of each iteration, a new module is completed or an existing one is improved on, the module is integrated into the structure, and the structure is then tested as a whole.
For example, using the iterative development model, a project can be divided into 12 one- to four-week iterations. The system is tested at the end of each iteration, and the test feedback is immediately incorporated at the end of each test cycle. The time required for successive iterations can be reduced based on the experience gained from past iterations. The system grows by adding new functions during the development portion of each iteration. Each cycle tackles a relatively small set of requirements; therefore, testing evolves as the system evolves. In contrast, in a classic waterfall life cycle, each phase (requirement analysis, system design, and so on) occurs once in the development cycle for the entire set of system requirements.
The main advantage of the iterative development model is that corrective actions can be taken at the end of each iteration. The corrective actions can be changes to the specification because of incorrect interpretation of the requirements, changes to the requirements themselves, and other design or code-related changes based on the system testing conducted at the end of each cycle.
The main disadvantages of the iterative development model are as follows:

• The communication overhead for the project team is significant, because each iteration involves giving feedback about deliverables, effort, timelines, and so on.
• It is difficult to freeze requirements, and they may continue to change in later iterations because of increasing customer demands. As a result, more iterations may be added to the project, leading to project delays and cost overruns.
• The project requires a very efficient change control mechanism to manage changes made to the system during each iteration.

More about Waterfal Model .........

Waterfall Model

The waterfall model is one of the earliest structured models for software development. It consists of the following sequential phases through which the development life cycle progresses:

• System feasibility. In this phase, you consider the various aspects of the targeted business process, find out which aspects are worth incorporating into a system, and evaluate various approaches to building the required software.
• Requirement analysis. In this phase, you capture software requirements in such a way that they can be translated into actual use cases for the system. The requirements can derive from use cases, performance goals, target deployment, and so on.
• System design. In this phase, you identify the interacting components that make up the system. You define the exposed interfaces, the communication between the interfaces, key algorithms used, and the sequence of interaction. An architecture and design review is conducted at the end of this phase to ensure that the design conforms to the previously defined requirements.
• Coding and unit testing. In this phase, you write code for the modules that make up the system. You also review the code and individually test the functionality of each module.
• Integration and system testing. In this phase, you integrate all of the modules in the system and test them as a single system for all of the use cases, making sure that the modules meet the requirements.
• Deployment and maintenance. In this phase, you deploy the software system in the production environment. You then correct any errors that are identified in this phase, and add or modify functionality based on the updated requirements.

The waterfall model has the following advantages:

• It allows you to compartmentalize the life cycle into various phases, which allows you to plan the resources and effort required through the development process.
• It enforces testing in every stage in the form of reviews and unit testing. You conduct design reviews, code reviews, unit testing, and integration testing during the stages of the life cycle.
• It allows you to set expectations for deliverables after each phase.

The waterfall model has the following disadvantages:

• You do not see a working version of the software until late in the life cycle. For this reason, you can fail to detect problems until the system testing phase. Problems may be more costly to fix in this phase than they would have been earlier in the life cycle.
• When an application is in the system testing phase, it is difficult to change something that was not carefully considered in the system design phase. The emphasis on early planning tends to delay or restrict the amount of change that the testing effort can instigate, which is not the case when a working model is tested for immediate feedback.
• For a phase to begin, the preceding phase must be complete; for example, the system design phase cannot begin until the requirement analysis phase is complete and the requirements are frozen. As a result, the waterfall model is not able to accommodate uncertainties that may persist after a phase is completed. These uncertainties may lead to delays and extended project schedules.

Software Testing Methodologies

The best methodologies are:

AGILE SOFTWARE DEVELOPMENT

Agile Software Development

Agile development methods tend to promote teamwork and collaboration. The agile development process isn’t sequential (code, test, debug, release), like traditional development processes; nor is it iterative; it combines concepts of both.
Twelve principles underlie the Agile Manifesto, including:

• Customer satisfaction by rapid delivery of useful software
• Welcome changing requirements, even late in development.
• Working software is delivered frequently (weeks rather than months)
• Working software is the principal measure of progress
• Sustainable development, able to maintain a constant pace
• Close, daily cooperation between businesspeople and developers
• Face-to-face conversation is the best form of communication (co-location)
• Projects are built around motivated individuals, who should be trusted
• Continuous attention to technical excellence and good design
• Simplicity
• Self-organizing teams
• Regular adaptation to changing circumstances

CLEANROOM SOFTWARE ENGINEERING

The Cleanroom Software Engineering process is a software development process intended to produce software with a certifiable level of reliability:

• Cleanroom development uses on formal methods in the design and specification of a software product. A team verifies that the design correctly implements the spec.
• Development and testing is done using an iterative approach, where functionality is added to the product incrementally (as opposed to creating all of the functionality first, THEN testing it).
• Software testing is performed as a statistical experiment.

ITERATIVE SOFTWARE DEVELOPMENT

Iterative Software Development

Iterative development is at the heart of a cyclic software development process; it starts with an initial planning and ends with deployment with the cyclic interactions in between.
Iterative development is NOT the same thing as incremental development, although the two methodologies do complement each other.
Two steps are involved in iterative development:

• Initialization: Creates a base version of the system.
• Iteration: The current version of the system is analyzed, and is redesigned and implemented based on the Project Control list.

RAPID APPLICATION DEVELOPMENT (RAD)

In place of extensive planning, RAD makes heavy use of prototyping.
In Rapid Application Development, structured techniques and prototyping are especially used to define users’ requirements and to design the final system. The development process starts with the development of preliminary data models and business process models using structured techniques. In the next stage, requirements are verified using prototyping, eventually to refine the data and process models. These stages are repeated iteratively.

RATIONAL UNIFIED PROCESS (RUP)

The Rational Unified Process is a framework intended to be customized by software development teams, for their individual needs. It was created by Rational Software (which is now part of IBM).
RUP emphasises six best practices for modern software engineering:

1. Develop iteratively, with risk as the primary iteration driver
2. Manage requirements
3. Employ a component-based architecture
4. Model software visually
5. Continuously verify quality
6. Control changes

Rational Unified Processing

SPIRAL SOFTWARE DEVELOPMENT

The Spiral Model is an iterative model that attempts to combine advantages of the top-down and bottom-up models of software design.

Spiral Software Development

The system requirements are defined in as much detail as possible. This usually involves interviewing a number of users representing all the external or internal users and other aspects of the existing system.

• A preliminary design is created for the new system. This phase is the most important part of the Spiral Model.

• A first prototype of the new system is constructed from the preliminary design.

• A second prototype is evolved by a fourfold procedure:

1. evaluating the first prototype in terms of its strengths, weaknesses, and risks;
2. defining the requirements of the second prototype;
3. planning and designing the second prototype;
4. constructing and testing the second prototype.

WATERFALL SOFTWARE DEVELOPMENT

Waterfall Software Development

The waterfall model is a sequential design process comprised of the following steps, each of which must be completed before the next starts:

1. Design
2. Construction/implementation
3. Integration
4. Testing/debugging/validation)
5. Installation
6. Maintenance

XP

Extreme Programming

Extreme Programming (XP) is intended to improve software quality and responsiveness to changing customer requirements. by advocating frequent “releases” in short development cycles, which is intended to improve productivity and introduce checkpoints where new customer requirements can be adopted. Features are not added until they are actually needed. Extreme Programming also encourages programming in pairs, along with frequent communication between members of the development team, and between the developers and clients.

Lean

Lean development could be summarized by seven principles, very close in concept to lean manufacturing principles.
Everything not adding value to the customer is considered to be waste, including:

• unnecessary code and functionality
• delay in the software development process
• unclear requirements
• bureaucracy
• slow internal communication

In order to be able to eliminate waste, one should be able to recognize and see it. If some activity could be bypassed or the result could be achieved without it, it is waste. Partially done coding eventually abandoned during the development process is waste. Extra processes and features not often used by customers are waste. Waiting for other activities, teams, processes is waste. Defects and lower quality are waste. Managerial overhead not producing real value is waste.

Scrum

Scrum is an iterative methodology used in agile software development.
During each “sprint”, typically a two to four week period (with the length being decided by the team), the team creates a potentially shippable product increment (for example, working and tested software). The set of features that go into a sprint come from the product “backlog”, which is a prioritized set of high level requirements of work to be done. Development is timeboxed such that the sprint must end on time; if requirements are not completed for any reason they are left out and returned to the product backlog. After a sprint is completed, the team demonstrates how to use the software.

V-Model

V-Model

The V-model is a software development process which may be considered an extension of the waterfall model. Instead of moving down in a linear way, the process steps are bent upwards after the coding phase, to form the typical V shape. The V-Model demonstrates the relationships between each phase of the development life cycle and its associated phase of testing.

TDD

Test-driven development (TDD) is a software development process that relies on the repetition of a very short development cycle: first the developer writes a failing automated test case that defines a desired improvement or new function, then produces code to pass that test and finally refactors the new code to acceptable standards.

Certifications

Testing / Quality / Automation / Performance / Security / Management - Certifications

1	CSQA	link

Performance / Load / Stress ......types of Testings

About Performance & Load Testing

Sl No	Title	Title
1.	Introduction
2.	Product or application performance measuring types	Different types like perf vs load vs stress
3.	What to measure & analyze	How
4.	System or setup requirements	How to monitor (monitor tools) the SUT
5.	List of Tools
6.	OpenSTA
7.	WebLoad
8.	JMeter
9.	TestMaker	It is opensource tool, can be used for functional, load & webservice testings.  It can be integrated with Selenium, JUnit, SoapUI & many other tools.
10.	Apache benchmarking ( tools & articles)	1. apache benchmark article 2. Apache benchmarking tools
11	Tools to measure the website performance
12	Tools to analyze the web pages
13	Top 15 best performance tools
14	Web page speed testing tool