CH3
What is scrum?
A general agile method but its focus is on managing iterative development rather than specific practices. The whole team attends short daily meetings where all team members share information, describe their progress since the last meeting, problems that have arisen and what is planned for the following day.
What is the sprint cycle?
Assess, Select, Develop, Review.
Plan-drive vs Agile?
Plan-driven: seperate development stages in order to advance. Agile: Specs, Design, Implentation, and Testing are interleaved.
Scrum Master?
Pretty much the project manager, he is the facilitator who arranges daily meetings, tracks the backlog of work to be done, records decisions, measures progress against the backlog and communicates with customers and management outside of the team.
Test-first development?
Where tests are written as programs rather than data so that they can be executed automatically. The test includes a check that it has executed correctly. These testing components should be stand-alone, should simulate the submission of input to be tested and should check that the result meets the output specification.
Scaling out?
is concerned with how agile methods can be introduced across a large organization with many years of software development experience.
Scaling up?
is concerned with using agile methods for developing large software systems that cannot be developed by a small team.
Is an incremental delivery strategy, where you deliver the software to customers and get rapid feedback from them, realistic?
Agile
XP Release Cycle?
Continuous loop of - Select user stories for this release > Break down stories to tasks > plan release > Develop/integrate/test software > release software > Evaluate system >>>
The principles of agile methods?
Customer Involvement Incremental Delivery People not process Embrace Change Maintain simplicity
Pair programming?
In XP, programmers work in pairs, sitting together to develop code. This helps common ownership of code and spreads knowledge across the team.
Rapid SW Development?
In rapid sw development specification, design, and implementation are inter-leaved. Systems are developed as a series of versions with stakeholders involved in version evaluation.
XP programming practices?
Incremental planning Small releases Simple design Test-first development Refactoring Pair programming Collective ownership Continuous integration Sustainable pace On-site customer
In Agile Manifesto we have come to value?
Individuals and interactions over processes and tools. Working sw over comprehensive documentation. Customer collaboration over contract negotiation. Responding to change over following a plan.
Problems with agile methods?
It can be difficult to keep the interest of customers who are involved in the process. Team members may be unsuited to the intense involvement that characterizes agile methods. Prioritizing changes can be difficult where there are multiple stakeholders. Maintaining simplicity requires extra work. Contracts may be a problem as with other approaches to iterative development.
Advantages of pair programming?
It supports the idea of collective ownership and responsibility for the system. Individuals are not held responsible. It acts as an informal review process because each line of code is looked at by at least two people. It helps support refactoring, which is a process of software improvement.
What is XP Programming?
Perhaps the best-known and most widely used agile method. New versions may be built several times per day, increments are delivered to customers every 2 weeks, all tests must be run for every build and is build is only accepted if tests run successfully.
Is it important to have a very detailed specification and design before moving to implementation?
Plan-driven
XP testing difficulties?
Programmers prefer programming to testing and sometimes they take short cuts when writing tests. For example, they may write incomplete tests that do not check for all possible exceptions that may occur. Some tests can be very difficult to write incrementally. For example, in a complex user interface, it is often difficult to write unit tests for the code that implements the 'display logic' and workflow between screens. It is difficult to judge the completeness of a set of tests. Although you may have a lot of system tests, your test set may not provide complete coverage.
Refactoring?
Programming team look for possible software improvements and make these improvements even where there is no immediate need for them.
Three phases in Scrum?
The initial phase is an outline planning phase where you establish the general objectives for the project and design the software architecture. This is followed by a series of sprint cycles, where each cycle develops an increment of the system. The project closure phase wraps up the project, completes required documentation such as system help frames and user manuals and assesses the lessons learned from the project. Outline planning and architectural design > sprint cycle > project closure.
Scrum benefits?
The product is broken down into a set of manageable and understand chunks. Unstable requirements do not hold up progress. The whole team have visibility of everything and consequently team communication is improved. Customers see on-time delivery of increments and gain feedback on how the product works. Trust between customers and developers is established and a positive culture is created in which everyone expect the project to succeed.
XP and Agile Principles?
incremental development is supported through small, frequent system releases, customer involvement means full-time customer engagement with the team, people not process through pair programming, collective ownership and a process that avoids long working hours, change supported through regular system releases, maintaining simplicity through constant refactoring of code.
