- Scrum (development)
Scrum is an iterative incremental process of software development commonly used with
agile software development . Despite the fact that "Scrum" is not an acronym, some companies implementing the process have been known to adhere to an all capital letter expression of the word, i.e. SCRUM. This may be due to one of Ken Schwaber's early papers capitalizing SCRUM in the title.cite book|title=Agile Project Management with Scrum|last=Schwaber|first=Ken|authorlink=Ken Schwaber|publisher=Microsoft Press |isbn=978-0-735-61993-7|date=1 February 2004]Although Scrum was intended to be for management of software development projects, it can be used in running software maintenance teams, or as a program management approach.
History
In 1986,
Hirotaka Takeuchi andIkujiro Nonaka described a newholistic approach which increases speed and flexibility in commercialnew product development : [cite journal|url=http://apln-richmond.pbwiki.com/f/New%20New%20Prod%20Devel%20Game.pdf|format=PDF|title=The New New Product Development Game|last=Takeuchi|first=Hirotaka|authorlink=Hirotaka Takeuchi|coauthors=Nonaka, Ikujiro|journal=Harvard Business Review|year=1986|month=January-February|accessdate=2008-09-26] They compare this new holistic approach, in which the phases strongly overlap and the whole process is performed by one cross-functional team across the different phases, to rugby, where the whole team "tries to go to the distance as a unit, passing the ball back and forth". The case studies come from the automotive, photo machine, computer and printer industries.In 1991, DeGrace and Stahl, in "Wicked Problems, Righteous Solutions" [cite book|title=Wicked problems, righteous solutions|last=DeGrace|first=Peter|coauthors=Stahl, Leslie Hulet|date=1 October 1990|isbn=978-0-135-90126-7|publisher=Prentice Hall] referred to this approach as Scrum, a rugby term mentioned in the article by Takeuchi and Nonaka. In the early 1990s,
Ken Schwaber used an approach that led to Scrum at his company, Advanced Development Methods. At the same time,Jeff Sutherland developed a similar approach at Easel Corporation and was the first to call it Scrum. [cite web|url=http://jeffsutherland.com/scrum/FirstScrum2004.pdf|format=PDF|title=Agile Development: Lessons learned from the first Scrum|last=Sutherland|first=Jeff|authorlink=Jeff Sutherland|year=2004|month=October|accessdate=2008-09-26] In 1995 Sutherland and Schwaber jointly presented a paper describing Scrum at OOPSLA '95 in Austin, its first public appearance. Schwaber and Sutherland collaborated during the following years to merge the above writings, their experiences, and industry best practices into what is now known as Scrum. In 2001 Schwaber teamed up withMike Beedle to write up the method in the bookAgile Software Development with SCRUM .Characteristics of Scrum
Scrum is a process skeleton that includes a set of practices and predefined roles. The main roles in Scrum are the "ScrumMaster" who maintains the processes and works similar to a project manager, the "Product Owner" who represents the stakeholders, and the "Team" which includes the developers.
During each "sprint", a 15-30 day period (length decided by the team), the team creates an increment of "potential shippable" (usable) software. The set of features that go into each sprint come from the "product backlog", which is a prioritized set of high level requirements of work to be done. Which backlog items go into the sprint is determined during the "sprint planning meeting". During this meeting the Product Owner informs the team of the items in the product backlog that he wants completed. The team then determines how much of this they can commit to complete during the next sprint. During the sprint, no one is able to change the sprint backlog, which means that the
requirement s are frozen for a sprint.There are several implementations of systems for managing the Scrum process which range from yellow stickers and white-boards to software packages. One of Scrum's biggest advantages is that it is very easy to learn and requires little effort to start using.
crum roles
Several roles are defined in Scrum; these are divided into two groups;
pig s andchicken s, based on a joke about a pig and a chicken.page 7]A pig and a chicken are walking down a road. The chicken looks at the pig and says, "Hey, why don't we open a restaurant?" The pig looks back at the chicken and says, "Good idea, what do you want to call it?" The chicken thinks about it and says, "Why don't we call it 'Ham and Eggs'?" "I don't think so," says the pig, "I'd be committed but you'd only be involved."
So the "pigs" are committed to building software regularly and frequently, while everyone else is a "chicken": interested in the project but really irrelevant because if it fails they're not a "pig", that is they weren't the ones that committed to doing it. The needs, desires, ideas and influences of the "chicken" roles are taken into account, but not in any way letting it affect or distort or get in the way of the actual Scrum project.
"Pig" roles
"Pigs" are the ones committed to the project and the Scrum process; they are the ones with "their bacon on the line."
; Product Owner: The "Product Owner" represents the voice of the customer. They ensure that the Scrum Team works with the right things from a business perspective. The Product Owner writes User Stories, prioritizes them, then places them in the Product Backlog.; ScrumMaster (or Facilitator): "Scrum" is facilitated by a "ScrumMaster", whose primary job is to remove impediments to the ability of the team to deliver the sprint goal. The "ScrumMaster" is not the leader of the team (as they are self-organizing) but acts as a buffer between the team and any distracting influences. The ScrumMaster ensures that the Scrum process is used as intended. The ScrumMaster is the enforcer of rules .; Team: The team has the responsibility to deliver the product. A small team of 5-9 people with cross-functional skills to do the actual work (designer, developer etc.).
"Chicken" roles
Chicken roles are not part of the actual Scrum process, but must be taken into account. An important aspect of an Agile approach is the practice of involving users, business and stakeholders into part of the process. It is important for these people to be engaged and provide feedback into the outputs for review and planning of each sprint.
; Users: The software is being built for someone! "If software is not used" - much like 'the tree falling in a forest' riddle - "was it ever written?"; Stakeholders (Customers, Vendors): The people that will enable the project, but are only directly involved in the process at sprint reviews. ; Managers : People that will set up the environment for the product development organization.
The Scrum meeting
Each day during the sprint, a project status meeting occurs. This is called a "scrum" or "the daily standup". The scrum has specific guidelines:
* The meeting starts precisely on time. Often there are team-decided punishments for tardiness (e.g. money, push-ups, hanging a rubber chicken around your neck)
* All are welcome, but only "pigs" may speak
* The meeting istimebox ed at 15 minutes regardless of the team's size.
* All attendees should stand (it helps to keep meeting short)
* The meeting should happen at the same location and same time every dayDuring the meeting, each team member answers three questions:page 135]
* What have you done since yesterday?
* What are you planning to do by tomorrow?
* Do you have any problems preventing you from accomplishing your goal? (It is the role of the ScrumMaster to remember these impediments.)After each sprint a "sprint retrospective" is held, at which all team members reflect about the past sprint. The purpose of the retrospective is to make continuous process improvement. This meeting is timeboxed at four hours.
Scrum enables the creation of self-organizing teams by encouraging co-location of all team members, and verbal communication across all team members and disciplines that are involved in the project.
A key principle of Scrum is its recognition that during a project the customers can change their minds about what they want and need (often called requirements churn), and that unpredicted challenges cannot be easily addressed in a traditional predictive or planned manner. As such, Scrum adopts an empirical approach – accepting that the problem cannot be fully understood or defined, focusing instead on maximizing the team's ability to deliver quickly and respond to emerging requirements.
Documents
Product backlog
The product backlog is a high-level document for the entire project. It contains broad descriptions of all required features, wish-list items, etc. It is the "What" that will be built. It is open and editable by anyone. It contains rough estimates, usually in days. This estimate helps the Product Owner to gauge the timeline and, to a limited extent, priority (e.g. if "add spellcheck" feature is estimated at 3 days vs 3 months, that may affect the Product Owner's desire).
print backlog
The sprint backlog is a greatly detailed document containing information about "how" the team is going to implement the requirements for the upcoming sprint. Tasks are broken down into "hours" with no task being more than 16 hours. If a task is greater than 16 hours, it should be broken down further. Tasks on the sprint backlog are never assigned, rather tasks are signed-up for by the team members as they like.
Burn down
The
burn down chart is a publicly displayed chart showing the number of tasks remaining for the current sprint or the number of items on the sprint backlog. It should not be confused with an earned value chart. A burn down chart could be flat for most of the period covered by a sprint and yet the project could still be on schedule.Adaptive project management
Following are some general practices of Scrum:
* Customers become a part of the development team. (i.e. the customer must be genuinely interested in the output.)
* Like all other forms of agile software processes, Scrum has frequent intermediate deliveries with working functionality. This enables the customer to get working software earlier and enables the project to change its requirements according to changing needs.
* Frequent risk and mitigation plans developed by the development team itself. – Risk Mitigation, Monitoring and Management (risk analysis) at every stage and with commitment.
* Transparency in planning and module development – Let everyone know who is accountable for what and by when.
* Frequent stakeholder meetings to monitor progress – Balanced (Delivery, Customer, Employee, Process) Dashboard updates – Stakeholders' update – You have to have Advance Warning Mechanism, i.e. visibility to potential slippage / deviation ahead of time.
* No problems are swept under the carpet. No one is penalized for recognizing or describing any unforeseen problem.
* Workplaces and working hours must be energized. – "Working more hours" does not necessarily mean "producing more output."crum terminology
Wikimedia Foundation. 2010.
