Scrum Development Model

1. What is scrum?

Scrum (a British rugby competition team), software development model is a kind of agile development. It has become popular in the past one or two years.

The basic assumption of scrum is:

Developing software is like developing new products. It is impossible to define the final procedure of software products from the very beginning. R & D, creativity, and attempt errors are required in the process, therefore, there is no fixed process to ensure project success. Scrum compares the software development team to an olive team, has a clear highest goal, is familiar with the best model and technology required in the development process, has a high degree of autonomy, and closely communicates and cooperates, resolve various challenges with high elasticity and ensure that every day and every stage is clearly oriented towards the goal.

The SCRUM development process usually takes 30 days (or a shorter period of time) as a stage, starting with the requirement specifications of new products provided by the customer, the development team and the customer select the completed specification at the beginning of each stage. The development team must try its best to deliver the results 30 days later. The team will have a 15-minute meeting every day to check the progress and plan of each member, understand the difficulties encountered and try to eliminate them.

2. Advantages of scrum over traditional development models

A notable feature of the scrum model is its ability to respond to changes as quickly as possible. The following figure uses a traditional software development model (waterfall model, spiral model, or iterative model ). As the complexity of system factors (internal and external factors) increases, the possibility of project success rapidly decreases.

It is a comparison between the scrum model and the traditional model:

Three scrum Models

1) several terms about scrum

Backlog: all tasks that can be predicted, including functional and non-functional tasks.

Sprint: The time cycle of a down generation development. Generally, a maximum of 30 days is used as a cycle. during this period, the development team needs to complete a developed backlog, and the final result is an incremental and deliverable product.

Sprint backlog: the task to be completed within a sprint cycle.

Scrummaster: A team member responsible for supervising the entire scrum process and revising the plan.

Time-box: A meeting time period. For example, the time-box of each daily scrum meeting is 15 minutes.

Sprint Planning Meeting: This is done before each sprint is started. Generally, it is a day (8 hours ). The task required for this meeting is: the product owner and team members break down the backlog into small functional modules and decide how many small functional modules need to be completed in the upcoming sprint, determine the task priority of this product backlog. In addition, the Meeting also needs to discuss in detail how to complete these small functional modules as needed. The workload of these modules is calculated by hour.

Daily scrum meeting: a member of the development team, usually 15 minutes. Each developer needs to report three projects to scrummaster: what has been done today? Have you encountered any obstacles? What will we do soon? Through this meeting, the team members can understand the project progress.

Sprint Review Meeting: after each sprint ends, this team will present the Sprint's work results to the product owner and other related personnel. Generally, this meeting is 4 hours.

Sprint detail spective meeting: Summarize the final sprint. Participants of the meeting are internal personnel developed by the team. Generally, this meeting is three hours.

Ii) implementation of scrum

1) the product's backlog is divided into sprint backlog, which can be completed according to the current human and material resources.

2) Hold the sprint planning meeting, divide the tasks to be completed in the sprint, mark the priority of the tasks and assign them to each member. Note that the task here is calculated by hour instead of by day.

3) In the sprint development cycle, daily scrum meeting needs to be held every day.

4) when the entire sprint cycle ends, the sprint review meeting will be held to present the results to the product owner.

5) The team members finally hold the sprint into spective meeting to summarize the problems and experiences.

6) perform the next sprint following the same steps.

Shows the entire process.