Explain Scrum - a type of an agile method?

Scrum as we all know is the agile software development methodology most in use nowadays for the development of many types of software systems and applications. It has been classified under the category of iterative and incremental development methodologies that works in an excellent way in managing the software products and projects. It also helps in management of the application development. 

Roles & Methods for Scrum Methodology

Some sets of predefined roles and methods have been defined for the scrum methodology:

1. The development team: It involves a team that is cross functional and self organized and takes care of the following processes:

          (a)    Analysis

(b)   Designing

(c)    Implementation

(d)   Testing and so on.  

At the end of each sprint, a shippable product is to be delivered by the development team. A typical development team may constitute of 3 – 9 members with self organizing skills which are required even though there is an interaction with the PMOs or project management organizations.

2. The product owner: The product owner is the representative of all the stake holders and sometimes may also represent the business. He/ she can also be regarded as the soul voice of the customer and he/ she is responsible for the following activities:

          (a)    Writing the customer centric items or user stories

(b)   Prioritizing the requirements based up on the user stories

(c)    Adding those identified requirements to the back log of the product.

This role is not supposed to be combined with the next one i.e., the scrum master.

3. The scrum master: The scrum master is responsible for ensuring that the whole process if followed and the impediments to the ability of the team are removed so as to make the delivery of the sprint goals easy and early. He is the one who facilitates the whole scrum development process. Scrum master as the name suggests should not be mistaken as the leader of the development team, he is in fact a buffer between the distracting influences and the development team. In a way he/ she make sure that the development process takes the intended route and enforces the rules to do so.

The above mentioned roles are called the core roles and there is another class of roles called the “ancillary roles” and as such they have no formal role but they have to be taken in to account. They have been mentioned below:

1. The stake holders and
2. The managers.

How Scrum is Useful?

- Scrum is quite useful when it comes to the management of the agile projects since it reinforces the interest in the agile development of the project. 

- The scrum and agile development method had come to challenge the conventional ideas regarding the agile project management. 

- Scrum methodology helps in the agile development at the steps where it becomes difficult to set the plan for upcoming processes. 

- The scrum and agile development methodology makes use of the concepts quite contrary to those used by the traditional development methods i.e., the mechanism of the empirical process control.

- Here the core management technique is constituted by the feedback loops. 

- The traditional development methods were command and control oriented.

- This mixed methodology of agile development and scrum has come to represent an entirely new radical approach that plans and manages the agile projects. 

- It has brought the level of the decision making authority to that of the operation certainties and properties.

- A project status meeting is held every day till the development continues which is called the “daily scrum”. 

- Below mentioned are some of the project management tools that support scrum:

1. Banana scrum
2. JIRA using Green Hopper plug-in
3. Mingle by thought works studios
4. Scrum Do
5. Pivotal tracker
6. Microsoft team foundation server

Estimation technique for an Agile Development

In previous posts, we have discussed various methods of estimation such as lines of code and function point. These are typically used for most software projects. But when you consider a project of very short software duration(consider a project which last just a few weeks) and also where there can be changes in requirements during the timeline of the project, it is difficult to use the lines of code or function point method. In such cases, one of the possible estimation technique is called estimation for agile development.

In a typical agile project, requirements are captured as stories or user scenarios; a different estimation method can be used for such projects. Some of the steps that are to be followed in such an agile project are:

- The estimation of each of the user stories is done on a standalone basis. Suppose the overall project has ten different user stories, we would need to do, at the minimum ten separate rounds of estimation.

- Each user story is further sub-divided into functions and tasks. Typically, each task is a separate discrete engineering unit, the start and end of which can be tracked separately from other tasks.

- Each task is a lowest unit at which estimation is done; at the end of the activity all the tasks have estimates. The engineering team is thus expected to provide estimates for each individual tasks.

- All these estimates for a user story are sum to create the total estimate for each user story.

- At a higher level, the estimates of all the user stories are summed to create the overall estimate.

Introduction to Crystal Agile Methodology and Agile Modeling

Crystal agile methodology is a software development approach. It is applicable for projects with small teams. It is a light weight approach. It is an adaptable approach. Crystal is a human powered methodology which means focus is on enhancing the work of the people. Crystal is ultra light which means it reduces the paper work, overhead involved. Crystal is stretch to fit methodology which means it grows just enough to get it to the right size. Crystal focuses on people and not processes.

Crystal consists of methodologies like Crystal Yellow, Crystal Orange, Crystal clear etc. It believes that project requires policies, practices and priorities as characteristics. Crystal methodology is based on the observation of various teams. Crystal methodology focuses on things that matter the most and make the most difference.

Agile Modeling suggests modeling is essential for all systems, but that the complexity, type, and size of the model must be in accordance with the software that is to be built. Some principles of agile methodology are:
- Agile Modeling is a practice based methodology.
- Values, principles and practices combine together for modeling.
- Agile Modeling is not a prescriptive process.
- Agile Modeling is not a complete software process.
- Agile Modeling focus on effective modeling and documentation.
- Developers using agile modeling should model with a purpose.
- Different models should be used to present different aspect and only those models should be kept that provide value.
- Traveling light is an appropriate approach for all software engineering work. Build only those models that provide value - no more, no less.
- During modeling, content is more important than representation.
- Be aware of the models and tools that are used to create them.
- The modeling approach should be able to adapt to the needs of agile team.

Agile modeling becomes difficult to implement in large teams, lack of modeling skills or team members are not co-located.

How to define a practice for agile testing ?

Practice for agile testing should encompass the following features:
Conversational Test Creation
- Test case writing should be a collaborative activity including majority of the entire team. As the customers will be busy, we should have someone representing the customer.
- Defining tests is a key activity that should include programmers and customer representatives.
- It should not be done alone.

Coaching Tests
- It is a way to think about acceptance tests.
- It turns user stories into tests.
- Tests should provide goals and guidance, instant feedback and progress measurement.
- Tests should be in specified in a format that is clear enough that users or customers can understand and that is specific enough that it can be executed.
- Specification should be done by example.

Providing Test Interfaces
- Developers are responsible for providing the fixtures that automate coaching tests.
- In most cases, extreme programming teams are adding test interfaces to their products, rather than using external test tools.

Exploratory Learning
- Plan to explore, learn and understand the product with each iteration.
- Look for bugs, missing features and opportunities for improvement.
- We do not understand software until we have used it.

What are the basic components of Extreme Programming (XP) ?

The basic components of Extreme Programming (XP) are:

Test-First Programming
- Developers write unit tests before coding. It has been noted that this kind of approach motivates the coding, speeds coding and also improves design results in better designs.
- It supports a practice called re-factoring.
- Agile practitioners prefer tests to text for describing system behavior. Tests are more precise than human language and they are also a lot more likely to be updated when the design changes. How many times have you seen design documents that no longer accurately described the current workings of the software? Out-of-date design documents look pretty much like up-to-date documents. Out-of-date tests fall.
- Many open source tools like xUnit have been developed to support this methodology.

Refactoring
- It is the practice changing a software system in such a way that it does not alter the external behavior of the code yet improves its internal structure.
- Traditional development tries to understand how all the code will work together in advance. This is the design. With agile methods, this difficult process of imagining what code might look like before it is written is avoided. Instead, the code is restructured as needed to maintain a coherent design.Frequent refactoring allows less up-front planning of design.
- Agile methods replace high level design with frequent re-design. It also requires a way of ensuring whether the behavior was not changed inadvertently. That's where the tests come in.
- Make the simplest design that will work and add completely only when needed and re-factor as necessary.
- Re-factoring requires unit tests to ensure that design changes do not break existing code.

Acceptance Testing
- Make up the user experiences or user stories which are short descriptions of the features to be coded.
- Acceptance tests verify the completion of user stories.
- Ideally, they are written before coding.

How much testing is relevant in an agile scenario?

Testing is as relevant in an agile scenario if not more than a traditional software development scenario. Testing is the headlight of the agile project showing where the project is standing now and the direction it is headed. Testing provides the required and relevant information to the teams to take informed and precise decisions. The testers in agile frameworks get involved in much more than finding software bugs, anything that can bug the potential user is a issue for them but testers do not make the final call, it is the entire team that discusses over it and takes a decision over a potential issues.
A firm belief of agile practitioners is that any testing approach does not assure quality, it's the team that does or does not do it, so there is a heavy emphasis on the skill and attitude of the people involved.
Agile testing is not a game of gotcha, it's about finding ways to set goals rather than focus on mistakes.
Among the agile methodologies, XP i.e. Extreme Programming components are:
- Test First Programming
- Pair Programming
- Short iterations and release.
- Re-factoring
- User Stories
- Acceptance Testing

Test-First Programming

- Developers write unit tests before coding. It has been noted that this kind of approach motivates the coding, speeds coding and also improves design results in better designs.
- It supports a practice called re-factoring.
- Agile practitioners prefer tests to text for describing system behavior. Tests are more precise than human language and they are also a lot more likely to be updated when the design changes. How many times have you seen design documents that no longer accurately described the current workings of the software? Out-of-date design documents look pretty much like up-to-date documents. Out-of-date tests fall.
- Many open source tools like xUnit have been developed to support this methodology.

Understanding Agile Testing and Agile Development Methodologies

First Definition: Agile testers treat the developers as their customer and follow the agile manifesto. The Context driven testing principles act as a set of principles for the agile tester.
Second Definition: It can also be treated as the testing methodology followed by testing team when an entire project follows agile methodologies.

Traditional QA seems to be totally at loggerheads with the agile manifesto in the following regard where process and tools are a key part of QA and testing, QA people seem to love documentation, QA people want to see the written specification and where is testing without a plan.
The question arises is there a role for QA in agile projects or not? The answer is maybe but the roles and tasks are different.

The context driven principles guidelines for the agile tester are:
- The value of any practice depends on its context.
- There are good practices in context, but there are no best practices.
- People, working together, are the most important part of any project's context.
- Projects unfold over time in ways that are often not predictable.
- The product is a solution. If the problem is not solved, the product does not work.
- Good software testing is a challenging intellectual process.
- Only through judgment and skill, exercised cooperatively throughout the entire project, are we able to do the right times to effectively test our products.

In the second definition, we described agile testing as a testing methodology adopted when an entire project follows agile development methodology.
Some agile development methodologies that are being practiced currently are extreme programming (XP), crystal, adaptive software development (ASD), scrum, feature driven development (FDD), dynamic systems development method (DSDM) and Xbreed.