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Agile Methodology Quick Memo

996worker
2022-03-14 / 0 评论 / 0 点赞 / 144 阅读 / 11,618 字
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Agile Methodology

Software Development Lifecycles (SDLCs)

Software development lifecycles (SDLCs) refer to a process for planning,
developing, testing, and deploying a software system. There are two main
types of SDLCs: formal and Agile.

SDLCType
WaterfallFormal
IncrementalFormal
V-ModelFormal
KanbanAgile
ScrumAgile
Extreme ProgrammingAgile

Agile was formed after teams were frustrated by the rigidity of formal
methods, and their inability to adapt to change easily without exceeding
cost and time constraints. For example, in Waterfall, teams complete all
the requirements work before moving to design and subsequently
development. If the requirements changed during the development phase,
the team would need to start over, costing significant time and money,
something that is not feasible in many situations.

Agile Manifesto

Agile, much like its name, focuses on being able to adapt to change
rapidly through developing software incrementally. The agile manifesto
explains the core values and principles that are the basis of Agile:

  • Individuals and interactions over processes and tools.
  • Working software over comprehensive documentation.
  • Customer collaboration over contract negotiation.
  • Responding to change over following a plan.

Scrum Framework

For this subject, you will work in agile teams following the Scrum
framework.

What is Scrum?

Scrum is a framework used to implement an Agile mindset. It focuses on ensuring teams
work together, embodying the values from the agile manifesto. Scrum is based on teams
working iteratively, in time-boxed sprints (typically 2-4 weeks), with a predetermined
set of tasks. During sprint planning, the team decides which tasks to work on during
the upcoming sprint, to ensure they maximise value to their client. If requirements
change, the teams can easily adapt as sprints are short, and the subsequent sprints
planning can re-prioritise the changed requirements.

Sprints

Sprints are a short time-boxed period in which a scrum team endeavours to complete a set
amount of work. The duration of sprints can be determined by teams, but typically duration
is between 2-4 weeks. As sprints have several ceremonies that must be
completed, teams should determine what works best for them.

Scrum Roles

Scrum teams have three key roles: product owner, scrum master, and development team members

Product Owner

The product owner ensures the team delivers the most value to the client. They have a strong
understanding of the project, which is used to prioritise user stories in upcoming sprints.

Product owners are required to maintain close ties with the client and
seek their validation and input. They are also the conduit for
communication with the client - all emails, meeting invites, etc. from
the team should be guided through the product owners to reach the
client.

Scrum Master

The scrum master is responsible for ensuring that the Scrum framework is
followed. Unlike a manager, the scrum master coaches the team rather
than leading them - scrum masters are servant leaders. They have no
authority to act as a manager in the traditional sense of being able to
allocate tasks. Instead, it is their responsibility to ensure that they
oversee how the project is tracking, and work to unblock developers to
continue meeting objectives.

Development Team

The development team refers to the team members who are implementing the
system. In your project, all team members must be a part of the
development team (including the Scrum master and product owner).

There are several other roles that teams may benefit from using. Please
note that these are not Scrum roles:

  • Quality Assurance/Testing lead: Monitors testing other initiatives
    to ensure the system is built to a high quality. Often, they are
    responsible for creating a testing plan and ensuring the testing
    objectives are met
  • Frontend lead: Oversees the frontend development of the project and
    is typically responsible for setting up and configuring the frontend
    codebase. Additionally, plays a key role in any decision-making
    about frontend architecture.
  • Backend lead: Oversees the backend development of the project and is
    typically responsible for setting up and configuring the backend
    codebase. Additionally, plays a key role in any decision-making
    about backend architecture.

Scrum Artefacts

Managing work in a scrum team involves the use of two artefacts:

  • Product backlog: Primary list of work that needs to be done which is
    maintained by the product owner.
  • Sprint backlog: The list of work that needs to be completed in the
    current sprint.

Scrum Ceremonies

Scrum ceremonies refer to a set of meetings that are used to manage the
development of a project. These ceremonies are important in facilitating
team communication and reducing the feedback loop. The table below shows
the key details of the Scrum ceremonies.

ceremonies.png

CeremonyWhenWhoPreparationDurationProcessOutcome
Sprint planningStart of each sprintDevelopment teamProduct owner should have a prioritised product backlog1 hour per week of sprint. E.g., 2-week sprints have a 2-hour session1. Product owner presents product backlog
2. Discussions with team about high priority features, which are then broken down into smaller tasks
3. Estimate the effort required for tasks.
4. Team agrees on the tasks set out for the sprint, and tasks are moved to the sprint backlog.
Populated sprint backlog in the team task tracking tool.
Stand-upWeeklyDevelopment team and supervisorNone<15 minutesEach team member says what they have done, what they will be working on and any blockers.
Sprint reviewEnd of each sprintDevelopment team and clientNone1 hourProduct owner presents the work completed in previous sprint and seeks feedback.Populated sprint review page in the team鈥檚 document repository.
Sprint retrospectiveEnd of each sprintDevelopment teamNone20 minsScrum master facilitates session to establish what the team thought went well, what did not work and what actions the team could do to improve.Populated retrospective page in the team鈥檚 document repository.

We have outlined how the scrum framework can assist teams in following
the agile manifesto. Now we will discuss how development requirements
can be represented.

Representing Requirements the Agile Way

Product requirements are a way of defining a product's purpose,
features, functionality, and behaviour. It serves as a common place to
develop and guide understanding for the technical team (the developers)
and the client to help build the product.

These requirements are then represented as initiatives, epics, tasks,
and subtasks.

requirements.png

Initiatives

In this subject you will only have one concurrent project, so the
project will count as the initiative. In a larger business where there
might be 2 or more applications under development simultaneously, there
would be 2 or more initiatives to cover each development.

Epics

An epic refers to a large body of work that can be broken down into user
stories. Epics cluster user stories that have a similar higher-level
objective.

Epics are a useful way to organise and create a hierarchy out of the
work. The goal of breaking down epics into user stories is to reduce the
amount of work required for the project into small, incremental tasks so
that value is delivered throughout the life of the project through the
completion of these smaller tasks. For client-based projects, this means
that you can deliver incremental progress and demonstrate value much
easier than if the tasks remained large pieces of work.

Epics generally have a duration greater than one sprint. As the team
progresses through the project and develops a better understanding of
the project and its requirements, user stories will naturally be added
and removed from an epic. This is exactly what we want in an epic
following agile methodology: a flexible scope that changes based on
client feedback and team progress.

User Stories

A user story is the smallest unit of work in the agile framework. A user
story may have one or many subtasks, but user stories are considered the
smallest piece of work that constitutes an end goal from a user's
perspective. A user story is an end goal, not a feature, expressed from
the perspective of the software user.

As discussed, user stories refer to a way of writing requirements from
the perspective of the end-user. By doing this, requirements follow the
agile methodology and are focused on the value delivered to the
end-user.

A key component of agile software development is putting people first,
and a user story puts end-users at the centre of the conversation. User
stories use non-technical language to provide context for the
development team. From reading a user story, the developer doing the
work required for that user story knows what they are building, why they
are building, for whom they are building it, and what value it creates.

How to Write a User Story

When first created, user stories consist of only one sentence in simple
language meant to outline the desired outcome - they don't go into
detail. User stories are expanded upon later and more details are added
to the user story, as agreed by the team, as work begins on the issue.

User stories are written to be non-technical following the format:

As a [role], I want to [goal], so that I can [benefit].

As an example, a company like Facebook might create a user story for new
functionality for their website with the following format:
As an individual user, I want to upload a photo to my profile picture,
so that people who search for my name can see a photo of me.

Story Points: User Story Estimation Metric

As user stories reflect requirements that a developer must implement,
they should have a corresponding estimate for the effort required to
develop the functionality. This is necessary for time-boxed projects to
estimate the time to delivery for new functionality. However,
estimations in the Agile world are not based on time, but instead use
story points.

Story points estimate a task by considering the amount of work that
needs to be done, the difficulty of the task and any potential risk or
uncertainty involved. This is a better estimate as using the time taken
to complete a task can vary from developer to developer depending on
their level of experience.

Various scales can be used for story points. Two common methods used
are:

  • Fibonacci sequence (1, 2, 3, 5, 8...)
  • T-shirt sizing (XS, S, M, L, XL)

Regardless of which estimation technique your team chooses to use, you
should have the estimation technique documented in your team's document
repository.

Estimation Process

The estimation process occurs during sprint
planning
. There are several ways to estimate the
story points of a user story - we will look at planning poker today:

  1. All members are given cards that have a story point value. If using
    Fibonacci sequence, would have cards for 0, 1, 2, 3, 5, 8, 13...
  2. Product owner reads out a user story and clarifies details if anyone
    has any questions.
  3. Team discusses how they will handle the task and what skills are
    required to understand the approach.
  4. Each member picks a card with a story point value they feel matches
    the user story just discussed, and places it face-down.
  5. Once all team members have chosen a card, the team turns over all
    the cards and discusses.
  6. Once the team reaches a consensus on the user story's estimate, the
    product owner notes down the value.
  7. Repeat until all user stories product owner has prepared are
    complete.

The estimates should be added to your chosen task tracking tool.

User Story Prioritisation

To deliver greater value to your client, you will want to invest your
efforts in tasks that are of importance first. The importance of tasks
is decided in discussions with the client (it is not up to the
development team to decide priority). One method of displaying the
priority of a task is the MoSCoW task prioritisation method. Priorities
are broken down into different levels of priority:

  • Must have: features that must be delivered or the software will not
    create the expected value for the client;
  • Should have: features that have significant value to the client and
    should be delivered, but not considered crucial;
  • Could have: features that the client considers nice to have but will
    not have a material impact to value, if not delivered; and
  • Won't have: out-of-scope features; useful as next steps for your
    project as potential improvements for future releases.
LinkDescription
MoSCoW methodFurther discussion of the MoSCoW method.
Scrum GuideComprehensive Scrum guide.
Sprint planning meetingDetails on running your sprint planning meeting.

:::

Once written, these stories should be documented centrally in the team's
document repository:

confluence.png

User Story Mapping

User story maps are intended to spark collaboration across agile team members, while providing them
with the bigger picture of how the backlog stories fit together into a larger vision of the product your team
is building. In agile team, product work exists as discrete backlog tasks and so visual tools are extremely helpful
in communicating deadlines, goals, and the final product to developers in the team, as well as the client.
This guarantees everyone is working towards the same ultimate goal.

Once created, the Product Owner is responsible for driving the creation of the user story map. However, it is
a group exercise and should be done by the entire team. Once created, it should then be communicated to the client.

When to Create User Story Maps

The user story map can be created before or after user story prioritisation. Sometimes it can help to visualise
user stories when prioritising them.

This is an example of a user story map:

user_story_map.jpg

To aid you in creating a user story map, you can make use of templates.

Copyright

By School of Computing and Information Systems, The University of Melbourne © Copyright 2021

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