Advantages of Agile model ?

 Advantages of Agile model:

• Customer satisfaction by rapid, continuous delivery of useful software.
• People and interactions are emphasized rather than process and tools. Customers, developers and testers constantly interact with each other.
• Working software is delivered frequently (weeks rather than months).
• Face-to-face conversation is the best form of communication.
• Close, daily cooperation between business people and developers.
• Continuous attention to technical excellence and good design.
• Regular adaptation to changing circumstances.
• Even late changes in requirements are welcomed

1. Revenue

The iterative nature of agile development means features are delivered incrementally, enabling some benefits to be realised early as the product continues to develop.

2. Speed-to-market

Research suggests about 80% of all market leaders were first to market. As well as the higher revenue from incremental delivery, agile development philosophy also supports the notion of early and regular releases, and ‘perpetual beta’.

3. Quality

A key principle of agile development is that testing is integrated throughout the lifecycle, enabling regular inspection of the working product as it develops. This allows the product owner to make adjustments if necessary and gives the product team early sight of any quality issues.

4. Visibility

Agile development principles encourage active ‘user’ involvement throughout the product’s development and a very cooperative collaborative approach. This provides excellent visibility for key stakeholders, both of the project’s progress and of the product itself, which in turn helps to ensure that expectations are effectively managed.

5. Risk Management

Small incremental releases made visible to the product owner and product team through its development help to identify any issues early and make it easier to respond to change. The clear visibility in agile development helps to ensure that any necessary decisions can be taken at the earliest possible opportunity, while there’s still time to make a material difference to the outcome.

6. Flexibility / Agility

In traditional development projects, we write a big spec up-front and then tell business owners how expensive it is to change anything, particularly as the project goes on. In fear of scope creep and a never-ending project, we resist changes and put people through a change control committee to keep them to the essential minimum. Agile development principles are different. In agile development, change is accepted. In fact, it’s expected. Because the one thing that’s certain in life is change. Instead the timescale is fixed and requirements emerge and evolve as the product is developed. Of course for this to work, it’s imperative to have an actively involved stakeholder who understands this concept and makes the necessary trade-off decisions, trading existing scope for new.

7. Cost Control

The above approach of fixed timescales and evolving requirements enables a fixed budget. The scope of the product and its features are variable, rather than the cost.

8. Business Engagement/Customer Satisfaction

The active involvement of a user representative and/or product owner, the high visibility of the product and progress, and the flexibility to change when change is needed, create much better business engagement and customer satisfaction. This is an important benefit that can create much more positive and enduring working relationships.

9. Right Product

Above all other points, the ability for agile development requirements to emerge and evolve, and the ability to embrace change (with the appropriate trade-offs), the team build the right product. It’s all too common in more traditional projects to deliver a “successful” project in IT terms and find that the product is not what was expected, needed or hoped for. In agile development, the emphasis is absolutely on building the right product.

10. More Enjoyable!

The active involvement, cooperation and collaboration make agile development teams a much more enjoyable place for most people. Instead of big specs, we discuss requirements in workshops. Instead of lengthy status reports, we collaborate around a task-board discussing progress. Instead of long project plans and change management committees, we discuss what’s right for the product and project and the team is empowered to make decisions. In my experience this makes it a much more rewarding approach for everyone. In turn this helps to create highly motivated, high performance teams that are highly cooperative.

Differences Between Agile and Waterfall Methodology

The traditional waterfall methodology for software development is rapidly losing its popularity as Agile methodology is now being increasingly adopted by companies worldwide for software development.

Waterfall basically is a sequential model where software development is segregated into a sequence of pre -defined phases – including feasibility, planning, design, build, test, production, and support. On the other hand, Agile development methodology follows a linear sequential approach while providing flexibility for changing project requirements, as they occur.

Here are the top 10 differences between Agile and Waterfall Methodology:

1.    The software development process is divided into different phases in the Waterfall model while Agile methodology segregates the project development lifecycle into sprints

2.    Waterfall is a structured software development methodology, and often times can be quite rigid, whereas the Agile methodology is known for its flexibility

3.    According to the Waterfall model, software development is to be completed as one single project, which is then divided into different phases, with each phase appearing only once during the SDLC. However, the Agile methodology can be considered as a collection of many different projects, which are nothing but the iterations of the different phases focusing on improving the overall software quality with feedbacks from users or the QA team

4.    If you want to use the Waterfall model for software development, then you have to be clear with all the development requirements beforehand as there is no scope of changing the requirements once the project development starts. The Agile methodology, on the other hand, is quite flexible, and allows for changes to be made in the project development requirements even after the initial planning has been completed

5.    All the project development phases such as designing, development, testing, etc. are completed once in the Waterfall model while as part of the Agile methodology, they follow an iterative development approach. As a result, planning, development, prototyping and other software development phases can appear more than once during the entire SDLC

6.    One of the major differences between Agile and Waterfall development methodology is their individual approach towards quality and testing. In the Waterfall model, the “Testing” phase comes after the “Build” phase, but, in the Agile methodology, testing is typically performed concurrently with programming or at least in the same iteration as programming

7.    While Waterfall methodology is an internal process and does not require the participation of customers, the Agile software development approach focuses on customer satisfaction and thus, involves the participation of customers throughout the development phase

8.    The Waterfall model can be regarded as a stringently sequential process, however, the Agile methodology is a highly collaborative software development process, thereby leading to better team input and faster problem solving

9.    The Waterfall model is best suited for projects which have clearly defined requirements and in which change is not expected at all, while Agile development supports a process in which the requirements are expected to change and evolve. Thus, if you are planning to develop a software that would require frequent overhauls and has to keep up with the technology landscape and customer requirements, Agile is the best approach to follow

10.  The Waterfall model exhibits a project mindset and lays its focus strictly on the completion of project development, while Agile introduces a product mindset that focuses on ensuring that the developed product satisfies its end customers, and changes itself as the requisites of customers change

What is Agile? In Software Engineering

 What is Agile? In Software Engineering

Agile SDLC model is a combination of iterative and incremental process models with focus on process adaptability and customer satisfaction by rapid delivery of working software product.

Agile Methods break the product into small incremental builds. These builds are provided in iterations. Each iteration typically lasts from about one to three weeks. Every iteration involves cross functional teams working simultaneously on various areas like planning, requirements analysis, design, coding, unit testing, and acceptance testing.

At the end of the iteration a working product is displayed to the customer and important stakeholders.

What is Agile?

Agile model believes that every project needs to be handled differently and the existing methods need to be tailored to best suit the project requirements. In agile the tasks are divided to time boxes (small time frames) to deliver specific features for a release.

Iterative approach is taken and working software build is delivered after each iteration. Each build is incremental in terms of features; the final build holds all the features required by the customer.

Here is a graphical illustration of the Agile Model:

Agile thought process had started early in the software development and started becoming popular with time due to its flexibility and adaptability.

The most popular agile methods include Rational Unified Process (1994), Scrum (1995), Crystal Clear, Extreme Programming (1996), Adaptive Software Development, Feature Driven Development, and Dynamic Systems Development Method (DSDM) (1995). These are now collectively referred to as agile methodologies, after the Agile Manifesto was published in 2001.

Following are the Agile Manifesto principles

·        Individuals and interactions - in agile development, self-organization and motivation are important, as are interactions like co-location and pair programming.

·        Working software - Demo working software is considered the best means of communication with the customer to understand their requirement, instead of just depending on documentation.

·        Customer collaboration - As the requirements cannot be gathered completely in the beginning of the project due to various factors, continuous customer interaction is very important to get proper product requirements.

·        Responding to change - agile development is focused on quick responses to change and continuous development.

what is waterfall model?

                   What is Waterfall Model design?

Waterfall approach was first SDLC Model to be used widely in Software Engineering to ensure success of the project. In "The Waterfall" approach, the whole process of software development is divided into separate phases. In Waterfall model, typically, the outcome of one phase acts as the input for the next phase sequentially.

Following is a diagrammatic representation of different phases of waterfall model.

The sequential phases in Waterfall model are:

·        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.

All these phases are cascaded to each other in which progress is seen as flowing steadily downwards (like a waterfall) through the phases. The next phase is started only after the defined set of goals are achieved for previous phase and it is signed off, so the name "Waterfall Model". In this model phases do not overlap.

Waterfall Model Application

Every software developed is different and requires a suitable SDLC approach to be followed based on the internal and external factors. Some situations where the use of Waterfall model is most appropriate are:

·        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.